BIOLOGY FINAL EXAM CRAM GUIDE CELL PARTS Cell Membrane * Controls what enters and leaves the cell. * Maintains homeostasis. Cytoplasm * Jelly-like fluid where organelles are located. Nucleus * Control center. * Contains DNA. Nucleolus * Makes ribosomes. Ribosomes * Make proteins. Rough ER * Protein production and transport. Smooth ER * Makes lipids and detoxifies chemicals. Golgi Apparatus * Packages and ships proteins. Mitochondria * Powerhouse of the cell. * Produces ATP (energy). Lysosome * Digests waste and old cell parts. Vacuole * Stores water, food, and waste. ⸻ PROKARYOTES VS EUKARYOTES Prokaryotes * No nucleus * No membrane-bound organelles * Smaller * Bacteria Eukaryotes * Has nucleus * Has organelles * Plants, animals, fungi, protists ⸻ DNA & RNA DNA Bases * A = T * C = G RNA Bases * A = U * C = G If DNA is: TAC RNA becomes: AUG AUG = Start codon (Methionine) Remember: DNA → mRNA → Protein ⸻ CODON CHART Each 3 RNA letters = 1 amino acid. Example: DNA: TAC GAA mRNA: AUG CUU Protein: Methionine – Leucine ⸻ GENE TERMS Gene * Section of DNA that codes for a trait. Genotype * Genetic makeup. * Example: AA, Aa, aa Phenotype * Physical appearance. * Example: Brown eyes ⸻ HOMOZYGOUS VS HETEROZYGOUS Homozygous Dominant AA Heterozygous Aa Homozygous Recessive aa Dominant = Capital letter Recessive = Lowercase letter ⸻ PUNNETT SQUARE Aa × Aa

Biologia Komórki: Rybosomy i Siateczka Śródplazmatyczna

bio Genetics is the study of heredity and how traits are passed from parents to offspring. Gregor Mendel is known as the “Father of Genetics.” Why did Mendel use pea plants? * Easy to grow * Short generation time * Many visible traits * Can self-pollinate or cross-pollinate * Produce many offspring Examples of traits studied: * Flower colour * Seed shape * Plant height ⸻ VOCABULARY Gene * A segment of DNA that controls a trait. Allele * Different forms of the same gene. Example: P = purple flowers p = white flowers Dominant Allele * Expressed whenever it is present. * Represented by a capital letter. Example: P = purple Recessive Allele * Only expressed when two copies are present. * Represented by a lowercase letter. Example: p = white Genotype * Genetic makeup of an organism. Examples: PP Pp pp Phenotype * Physical appearance of an organism. Examples: Purple flower White flower Homozygous * Two identical alleles. Examples: PP pp Heterozygous * Two different alleles. Example: Pp Pure Breeding * Homozygous for a trait. Gamete * Sex cell (sperm or egg). ⸻ MENDEL’S LAWS Law of Dominance * A dominant allele masks a recessive allele. Example: Pp = Purple flower Law of Segregation * Alleles separate during gamete formation. * Each gamete receives only one allele. Example: Parent = Pp Gametes: P p Law of Independent Assortment * Different genes assort independently during meiosis. ⸻ MONOHYBRID CROSSES A monohybrid cross studies one trait. Example: P = Purple p = White Cross: Pp × Pp Punnett Square INCOMPLETE DOMINANCE Neither allele completely dominates. Example: Snapdragons RR = Red WW = White RW = Pink Cross: RW × RW Genotype Ratio: 1 RR : 2 RW : 1 WW Phenotype Ratio: 1 Red : 2 Pink : 1 White CODOMINANCE Both alleles are expressed equally. Example: AB Blood Type Genotype: IAIB Phenotype: AB MULTIPLE ALLELES More than two alleles exist in a population. Example: ABO Blood Group Alleles: IA IB i BLOOD TYPES Type A Genotypes: IAIA or IAi Type B Genotypes: IBIB or IBi Type AB Genotype: IAIB Type O Genotype: ii Can Type A and Type B Parents Have a Type O Child? Yes. If: Father = IAi Mother = IBi Possible Blood Types: AB A B O CELL CYCLE Purpose: * Growth * Repair * Replacement of cells Stages: G1 S G2 Mitosis Cytokinesis INTERPHASE G1 Phase Cell grows and carries out normal functions. S Phase DNA replication occurs. G2 Phase Cell prepares for division. MITOSIS Purpose: Growth and repair. Produces: 2 genetically identical diploid cells. PROPHASE Events: * Chromosomes condense * Nuclear membrane disappears * Nucleolus disappears * Spindle fibres form METAPHASE Events: * Chromosomes line up at the equator ANAPHASE Events: * Sister chromatids separate TELOPHASE Events: * Nuclear membranes reform * Chromosomes uncoil CYTOKINESIS Division of the cytoplasm. Animal Cells: Cleavage furrow forms. Plant Cells: Cell plate forms. CHROMOSOME STRUCTURE Chromosome consists of: * Two sister chromatids * One centromere DIPLOID VS HAPLOID Diploid (2n) * Two sets of chromosomes * Human body cells * 46 chromosomes Haploid (n) * One set of chromosomes * Human gametes * 23 chromosomes HOMOLOGOUS CHROMOSOMES Chromosome pairs that: * Carry the same genes * One comes from the mother * One comes from the father Humans have 23 homologous pairs. MEIOSIS Purpose: Produce gametes. Produces: 4 genetically unique haploid cells. MEIOSIS I Separates homologous chromosomes. CROSSING OVER Occurs during Prophase I. Definition: Exchange of DNA between homologous chromosomes. Importance: Creates genetic variation. RANDOM ASSORTMENT Occurs during Metaphase I. Definition: Homologous pairs line up randomly. Importance: Creates unique chromosome combinations. MEIOSIS II Separates sister chromatids. MITOSIS VS MEIOSIS Mitosis * 2 cells produced * Diploid * Genetically identical * Growth and repair Meiosis * 4 cells produced * Haploid * Genetically different * Produces gametes NONDISJUNCTION Failure of chromosomes to separate properly during meiosis. Can result in extra or missing chromosomes. DOWN SYNDROME Cause: Extra chromosome 21. Chromosome Number: 47 Usually caused by nondisjunction during meiosis. DNA DNA = Deoxyribonucleic Acid Shape: Double Helix Function: Stores genetic information. NUCLEOTIDE Three Components: * Phosphate Group * Deoxyribose Sugar * Nitrogenous Base NITROGENOUS BASES Adenine (A) Thymine (T) Cytosine (C) Guanine (G) COMPLEMENTARY BASE PAIRING A pairs with T C pairs with G DNA REPLICATION Purpose: Make identical copies of DNA. Location: Nucleus Result: Two identical DNA molecules. TRANSCRIPTION Purpose: Create mRNA from DNA. Location: Nucleus DNA → mRNA Remember: RNA uses Uracil (U) instead of Thymine (T). TRANSLATION Purpose: Make proteins. Location: Ribosome mRNA is read and amino acids are joined together to form a protein. MUTATIONS A mutation is a change in DNA sequence. Types: * Deletion * Duplication * Inversion * Translocation DELETION DNA segment removed. DUPLICATION DNA segment repeated. INVERSION DNA segment reversed. TRANSLOCATION DNA segment moves to another chromosome. SEX-LINKED TRAITS Traits located on sex chromosomes. Most are located on the X chromosome. RED-GREEN COLOUR BLINDNESS Inheritance: X-linked recessive. XC = Normal Vision Xc = Colour Blind Male: XcY Colour blind boys inherit the allele from their mother because fathers pass a Y chromosome to their sons. TAY-SACHS DISEASE Cause: Missing enzyme that breaks down lipids in nerve cells. Inheritance: Autosomal recessive. Treatment: No cure currently available. SICKLE CELL ANEMIA Cause: Mutation in hemoglobin gene. Effects: * Sickle-shaped red blood cells * Reduced oxygen transport * Blocked blood vessels Inheritance: Autosomal recessive. HUNTINGTON’S DISEASE Cause: Dominant mutation. Effects: * Nervous system degeneration * Loss of motor control * Cognitive decline Inheritance: Autosomal dominant. KARYOTYPE A photograph of chromosomes arranged in pairs. Used to: * Determine sex * Detect chromosome abnormalities * Diagnose genetic disorders PEDIGREE A family tree used to track inheritance patterns. Symbols: Square = Male Circle = Female Shaded = Has trait CLONING Producing genetically identical organisms. Uses: * Research * Agriculture * Medicine * Conservation GENETIC COUNSELLING Provides information about: * Inherited disorders * Family risk * Testing options AMNIOCENTESIS Prenatal test in which amniotic fluid is sampled and fetal cells are analyzed. Can detect: * Genetic disorders * Chromosomal disorders GMOs Genetically Modified Organisms. Definition: Organisms whose DNA has been altered through biotechnology. Advantages: * Increased crop yield * Disease resistance * Pest resistance Disadvantages: * Ethical concerns * Environmental concerns DNA REPLICATION → TRANSCRIPTION → TRANSLATION DNA (Nucleus) ↓ Replication DNA Copy DNA ↓ Transcription mRNA mRNA ↓ Translation Protein Final Product: Protein RESPIRATORY SYSTEM Function: * Brings oxygen into the body * Removes carbon dioxide * Works with the circulatory system to supply cells with oxygen Why do organisms require oxygen and produce carbon dioxide? Oxygen is required for cellular respiration. Cellular Respiration: Glucose + Oxygen → Energy (ATP) + Carbon Dioxide + Water Cells use oxygen to release energy from food. Carbon dioxide is produced as a waste product and must be removed. ⸻ PATHWAY OF AIR Nasal Cavity ↓ Pharynx ↓ Larynx ↓ Trachea ↓ Bronchi ↓ Bronchioles ↓ Alveoli ⸻ NASAL CAVITY Functions: * Warms air * Moistens air * Filters air Nasal Hairs: * Trap large particles Mucus: * Traps dust and microorganisms Blood Capillaries: * Warm incoming air ⸻ PHARYNX Common passageway for: * Air * Food Also called the throat. ⸻ UVULA Functions: * Prevents food from entering nasal cavity * Helps with speech ⸻ EPIGLOTTIS Functions: * Covers trachea during swallowing * Prevents choking ⸻ LARYNX Also called the voice box. Contains vocal cords. ⸻ TRACHEA Also called the windpipe. Contains cartilage rings that prevent collapse. Lined with: * Cilia * Mucus ⸻ CILIA Tiny hair-like structures. Function: * Sweep mucus upward toward throat ⸻ BRONCHI Two branches of the trachea leading to lungs. Right Bronchus → Right Lung Left Bronchus → Left Lung ⸻ BRONCHIOLES Smaller branches inside lungs. Lead to alveoli. ⸻ ALVEOLI Tiny air sacs. Site of gas exchange. Adaptations: * Thin walls * Moist surface * Large surface area * Rich blood supply Gas Exchange: Oxygen moves: Alveoli → Blood Carbon Dioxide moves: Blood → Alveoli By diffusion. ⸻ BREATHING MECHANICS Two main muscles: 1. Diaphragm 2. Intercostal Muscles ⸻ INHALATION (INSPIRATION) Diaphragm: * Contracts * Moves downward Intercostal Muscles: * Contract * Lift ribs upward Result: * Chest cavity volume increases * Pressure decreases * Air enters lungs ⸻ EXHALATION (EXPIRATION) Diaphragm: * Relaxes * Moves upward Intercostal Muscles: * Relax Result: * Chest cavity volume decreases * Pressure increases * Air leaves lungs ⸻ MEDULLA OBLONGATA Located in the brainstem. Function: * Controls breathing rate Responds to: * Carbon dioxide levels More CO₂: * Faster breathing Less CO₂: * Slower breathing ⸻ LUNG VOLUMES Tidal Volume * Normal amount of air breathed in and out Inspiratory Reserve Volume * Extra air inhaled after normal breath Expiratory Reserve Volume * Extra air exhaled after normal breath Residual Volume * Air remaining in lungs after maximum exhalation Vital Capacity * Maximum amount of air exhaled after deepest breath Total Lung Capacity * Total amount of air lungs can hold ⸻ CIRCULATORY SYSTEM Functions: * Transport oxygen * Transport nutrients * Remove wastes * Maintain homeostasis * Transport hormones Humans have a CLOSED circulatory system. Blood remains inside vessels. ⸻ BLOOD VESSELS ARTERIES Function: * Carry blood away from heart Characteristics: * Thick walls * High pressure * Small lumen * No valves Usually oxygen-rich Exception: Pulmonary artery ⸻ VEINS Function: * Carry blood toward heart Characteristics: * Thin walls * Low pressure * Large lumen * Valves present Usually oxygen-poor Exception: Pulmonary vein ⸻ CAPILLARIES Smallest blood vessels. Functions: * Gas exchange * Nutrient exchange * Waste exchange Walls are one cell thick. ⸻ HEART STRUCTURE Blood Flow: Body ↓ Vena Cava ↓ Right Atrium ↓ Right Ventricle ↓ Pulmonary Artery ↓ Lungs ↓ Pulmonary Vein ↓ Left Atrium ↓ Left Ventricle ↓ Aorta ↓ Body ⸻ HEART CHAMBERS Right Atrium * Receives deoxygenated blood Right Ventricle * Pumps blood to lungs Left Atrium * Receives oxygenated blood Left Ventricle * Pumps blood to body ⸻ SEPTUM Wall separating left and right sides of heart. Prevents mixing of blood. ⸻ HEART VALVES Function: * Prevent backflow of blood Types: Atrioventricular (AV) Valves Pulmonary Semilunar Valve Aortic Semilunar Valve ⸻ SA NODE Sinoatrial Node Known as: * Natural pacemaker Initiates heartbeat. ⸻ AV NODE Atrioventricular Node Receives signal from SA node. Delays impulse slightly. Allows ventricles to fill before contraction. ⸻ BLOOD Components: 1. Plasma 2. Red Blood Cells 3. White Blood Cells 4. Platelets ⸻ PLASMA Liquid component of blood. Functions: * Transport nutrients * Transport hormones * Transport wastes ⸻ RED BLOOD CELLS (ERYTHROCYTES) Function: * Carry oxygen Contain: * Hemoglobin ⸻ HEMOGLOBIN Protein in red blood cells. Function: * Binds oxygen Allows oxygen transport. ⸻ WHITE BLOOD CELLS (LEUKOCYTES) Function: * Fight infection * Defend body Part of immune system. ⸻ PLATELETS Function: * Blood clotting Prevent blood loss. ⸻ BLOOD PRESSURE Force of blood against artery walls. Measured using: Sphygmomanometer Example: 120/80 120 = Systolic Pressure 80 = Diastolic Pressure ⸻ SYSTOLIC PRESSURE Pressure when heart contracts. ⸻ DIASTOLIC PRESSURE Pressure when heart relaxes. ⸻ HYPERTENSION High blood pressure. Can increase risk of: * Stroke * Heart attack * Kidney disease ⸻ STROKE VOLUME Amount of blood pumped per heartbeat. ⸻ CARDIAC OUTPUT Amount of blood pumped per minute. Formula: Cardiac Output = Heart Rate × Stroke Volume ⸻ ECG Electrocardiogram Measures electrical activity of heart. Used to detect: * Irregular heartbeat * Heart damage ⸻ PULMONARY CIRCULATION Heart → Lungs → Heart Purpose: * Oxygenate blood ⸻ SYSTEMIC CIRCULATION Heart → Body → Heart Purpose: * Deliver oxygen to tissues ⸻ HOMEOSTASIS DURING EXERCISE Body responds by: * Increasing heart rate * Increasing breathing rate * Increasing cardiac output * Redirecting blood to muscles * Sweating to cool body Purpose: Maintain stable internal conditions. ⸻ DIGESTIVE SYSTEM Functions: * Break down food * Absorb nutrients * Eliminate waste ⸻ DIGESTIVE TRACT Mouth ↓ Pharynx ↓ Esophagus ↓ Stomach ↓ Small Intestine ↓ Large Intestine ↓ Rectum ↓ Anus ⸻ MECHANICAL DIGESTION Physical breakdown of food. Examples: * Chewing * Churning ⸻ CHEMICAL DIGESTION Chemical breakdown of food using enzymes. Examples: * Amylase * Pepsin ⸻ SALIVA Functions: 1. Moistens food 2. Contains amylase Amylase begins carbohydrate digestion. ⸻ TONGUE Functions: 1. Forms bolus 2. Pushes food for swallowing ⸻ ESOPHAGUS Moves food to stomach. Uses: Peristalsis ⸻ PERISTALSIS Wave-like muscular contractions. Move food through digestive tract. ⸻ STOMACH Functions: * Stores food * Mixes food * Begins protein digestion Produces: * HCl * Pepsin * Mucus ⸻ HCl Hydrochloric Acid Functions: * Kills bacteria * Activates pepsin ⸻ PEPSIN Function: * Digests proteins ⸻ MUCUS Function: * Protects stomach lining ⸻ CHYME Semi-liquid food mixture leaving stomach. ⸻ HEARTBURN Cause: Stomach acid enters esophagus. Usually caused by weakened cardiac sphincter. ⸻ SMALL INTESTINE Main site of: * Digestion * Absorption Adaptations: * Long length * Folds * Villi * Microvilli Large surface area increases absorption. ⸻ DUODENUM First section. Functions: * Receives bile * Receives pancreatic enzymes * Most chemical digestion ⸻ JEJUNUM Main nutrient absorption. ⸻ ILEUM Final nutrient absorption. ⸻ VILLI Finger-like projections. Function: Increase surface area. ⸻ LIVER Functions: * Produces bile * Processes nutrients * Detoxifies blood ⸻ GALL BLADDER Functions: * Stores bile * Releases bile into small intestine ⸻ PANCREAS Functions: * Produces digestive enzymes * Produces bicarbonate ⸻ BILE Function: Emulsifies fats. Breaks large fat droplets into smaller droplets. Makes fat digestion easier. ⸻ DIGESTION OF CARBOHYDRATES Mouth: * Amylase begins digestion Small Intestine: * Pancreatic amylase continues digestion End Product: Glucose ⸻ DIGESTION OF PROTEINS Stomach: * Pepsin begins digestion Small Intestine: * Trypsin continues digestion End Product: Amino Acids ⸻ DIGESTION OF LIPIDS Small Intestine: * Bile emulsifies fats * Lipase digests fats End Product: Fatty Acids + Glycerol ⸻ EVOLUTION Evolution: Change in populations over time. Individuals do NOT evolve. Populations evolve. ⸻ DARWIN Proposed: Natural Selection Book: On the Origin of Species ⸻ WALLACE Independently developed theory of natural selection. ⸻ LAMARCK Proposed: Inheritance of acquired characteristics Example: Giraffes stretch necks and pass longer necks to offspring. This theory is incorrect. ⸻ NATURAL SELECTION Requirements: 1. Variation 2. Overproduction 3. Competition 4. Differential Survival 5. Reproduction Result: Adaptation ⸻ ADAPTATION Inherited characteristic that increases survival and reproduction. ⸻ SELECTIVE ADVANTAGE A characteristic that improves survival or reproduction. Example: Antibiotic resistance ⸻ SELECTIVE PRESSURE Environmental factor that influences survival. Examples: * Predators * Disease * Climate * Competition ⸻ VARIATION Differences among individuals in a population. Sources: * Mutation * Crossing Over * Random Assortment ⸻ MUTATION Ultimate source of new alleles. Creates genetic variation. ⸻ FOSSIL Preserved remains or traces of organisms. ⸻ FOSSIL RECORD Collection of fossils showing evolutionary history. Provides evidence for evolution. ⸻ RADIOACTIVE DATING Uses radioactive isotopes to determine fossil age. ⸻ UNIFORMITARIANISM Proposed by Lyell. Earth changes gradually over long periods of time. ⸻ CATASTROPHISM Proposed by Cuvier. Earth shaped by sudden catastrophic events. ⸻ BIOGEOGRAPHY Study of species distribution around Earth. Provides evidence for evolution. ⸻ EMBRYOLOGY Study of embryos. Similar embryos suggest common ancestry. ⸻ HOMOLOGOUS STRUCTURES Same evolutionary origin. Different functions. Example: Human arm Whale flipper Bat wing Evidence of common ancestry. ⸻ ANALOGOUS STRUCTURES Different origins. Same function. Example: Bird wing Insect wing Not evidence of close ancestry. ⸻ VESTIGIAL STRUCTURES Structures with little or no function. Examples: * Human appendix * Whale pelvis Evidence of evolution. ⸻ MIMICRY One species resembles another. Example: Syrphid fly resembles wasp. Provides protection. ⸻ ARTIFICIAL SELECTION Humans select traits. Examples: * Dog breeding * Crop breeding ⸻ DIRECTIONAL SELECTION One extreme phenotype favored. Graph shifts in one direction. ⸻ STABILIZING SELECTION Average phenotype favored. Extremes selected against. ⸻ DISRUPTIVE SELECTION Both extremes favored. Middle selected against. ⸻ GENETIC DRIFT Random change in allele frequencies. Most significant in small populations. ⸻ FOUNDER EFFECT Small group starts new population. Different allele frequencies from original population. ⸻ BOTTLENECK EFFECT Population drastically reduced. Loss of genetic variation. ⸻ GENE FLOW Movement of alleles between populations. Occurs through migration. ⸻ NON-RANDOM MATING Individuals choose specific mates. Can reduce variation. ⸻ SPECIES A group of organisms that can interbreed in nature and produce fertile offspring. ⸻ SPECIATION Formation of new species. ⸻ ALLOPATRIC SPECIATION Requires: Geographic isolation Example: Mountain separates populations. ⸻ SYMPATRIC SPECIATION Occurs without geographic isolation. ⸻ PRE-ZYGOTIC ISOLATION Prevents fertilization. Examples: * Different mating seasons * Different mating songs * Different habitats ⸻ POST-ZYGOTIC ISOLATION Occurs after fertilization. Example: Sterile hybrids Example: Mule DIVERSITY Prokaryotes vs Eukaryotes PROKARYOTES * No nucleus * No membrane-bound organelles * Circular DNA * Smaller * Examples: Eubacteria, Archaebacteria EUKARYOTES * Nucleus present * Membrane-bound organelles * Linear chromosomes * Larger * Examples: Protists, Fungi, Plants, Animals Three Differences: 1. Nucleus vs no nucleus 2. Organelles vs no organelles 3. Larger vs smaller ⸻ Taxonomy Kingdom Phylum Class Order Family Genus Species Mnemonic: King Philip Came Over For Good Soup ⸻ Binomial Nomenclature Genus + Species Example: Homo sapiens Rules: * Genus capitalized * Species lowercase * Italicized Purpose: * Universal naming system * Avoids confusion * Shows relationships ⸻ Dichotomous Key Used to identify organisms using paired choices. Example: 1a Has wings → Step 2 1b No wings → Step 3 ⸻ Six Kingdoms 1. Archaebacteria 2. Eubacteria 3. Protista 4. Fungi 5. Plantae 6. Animalia ⸻ VIRUSES Virus Structure: * DNA or RNA * Capsid * Attachment proteins * Sometimes envelope Why Viruses Are Not Living: * Not made of cells * Cannot reproduce independently * No metabolism * Need host cell ⸻ DNA Virus vs RNA Virus DNA Virus: * Contains DNA * More stable RNA Virus: * Contains RNA * Mutates faster ⸻ Lytic Cycle Attachment ↓ Penetration ↓ Replication ↓ Assembly ↓ Lysis Host cell bursts. ⸻ Lysogenic Cycle Attachment ↓ Penetration ↓ Integration into host DNA ↓ Host reproduces ↓ Virus DNA copied Cell survives initially. ⸻ ARCHAEBACTERIA Characteristics: * Prokaryotic * Unicellular * Extreme environments Three Groups: Methanogens * Produce methane Halophiles * Salt-loving Thermoacidophiles * Hot acidic environments ⸻ EUBACTERIA Characteristics: * Prokaryotic * Peptidoglycan cell wall * Binary fission Examples: * E. coli * Streptococcus ⸻ Binary Fission DNA Replication ↓ Cell Growth ↓ Cell Division ↓ Two Identical Cells ⸻ Conjugation DNA transfer through pilus. Importance: * Genetic variation * Antibiotic resistance ⸻ Antibiotic Resistance Mutation ↓ Antibiotic kills susceptible bacteria ↓ Resistant bacteria survive ↓ Resistant bacteria reproduce Natural Selection ⸻ PROTISTS Characteristics: * Eukaryotic * Mostly unicellular * Aquatic Three Groups: Animal-like * Amoeba * Paramecium Plant-like * Algae * Euglena Fungus-like * Slime molds ⸻ Amoeba * Uses pseudopods * Phagocytosis ⸻ Algae * Photosynthetic * Oxygen producer ⸻ Euglena * Chloroplasts * Flagellum * Photosynthesis * Can also feed heterotrophically ⸻ Malaria Cause: Plasmodium Kingdom: Protista ⸻ FUNGI Characteristics: * Eukaryotic * Heterotrophic * Chitin cell walls * Reproduce with spores Examples: * Mushrooms * Mold * Yeast ⸻ External Digestion Release enzymes ↓ Digest food outside body ↓ Absorb nutrients ⸻ Fungi vs Plants FUNGI * Heterotrophic * Chitin * No chloroplasts PLANTS * Autotrophic * Cellulose * Chloroplasts ⸻ PLANTS Biodiversity vs Monoculture BIODIVERSITY * Many species * Stable ecosystem * Disease resistance MONOCULTURE * One crop species * Low diversity * Disease risk ⸻ Bryophytes Definition: Nonvascular plants Examples: * Mosses * Liverworts Characteristics: * No xylem * No phloem * Need water for reproduction ⸻ Vascular Plants Contain: * Xylem * Phloem ⸻ Xylem Function: Water and minerals Direction: Roots → Leaves ⸻ Phloem Function: Sugars Direction: Throughout plant ⸻ Alternation of Generations Sporophyte (2n) ↓ meiosis Spores (n) ↓ Gametophyte (n) ↓ Gametes ↓ fertilization Zygote (2n) ↓ Sporophyte ⸻ Moss Life Cycle Spores ↓ Gametophyte ↓ Egg + Sperm ↓ Zygote ↓ Sporophyte ↓ Capsule ↓ Spores Know: * Capsule * Sporophyte * Gametophyte * Spores ⸻ Fern Life Cycle Fern ↓ Sori ↓ Spores ↓ Prothallus ↓ Gametes ↓ Fertilization ↓ Young Fern Know: * Frond * Sori * Sporangia * Prothallus ⸻ Gymnosperms Characteristics: * Naked seeds * Cones * Wind pollination * Evergreen Examples: * Pine * Spruce * Fir ⸻ Angiosperms Characteristics: * Flowers * Fruit * Seeds enclosed Examples: * Apple tree * Rose * Maple ⸻ Flower Structure Anther * Produces pollen Pollen Grain * Male gamete Stigma * Receives pollen Style * Connects stigma and ovary Ovary * Contains ovules Ovule * Female gamete Petals * Attract pollinators ⸻ Plant Tissues Meristematic * Growth Dermal * Protection Ground * Photosynthesis * Storage Vascular * Transport ⸻ Leaf Structure Blade * Main leaf surface Petiole * Connects leaf to stem Cuticle * Reduces water loss Palisade Mesophyll * Photosynthesis Spongy Mesophyll * Gas exchange Veins * Xylem + Phloem ⸻ Stomata Openings in leaves. Functions: * Gas exchange * Water loss ⸻ Guard Cells Control opening and closing of stomata. ⸻ Transpiration Water loss from leaves. Functions: * Pulls water upward * Cools plant * Moves minerals ⸻ Simple vs Compound Leaves Simple: * One blade Compound: * Multiple leaflets ⸻ Monocots vs Dicots MONOCOTS * 1 cotyledon * Parallel veins * Fibrous roots * Flower parts in 3s Examples: Corn Grass DICOTS * 2 cotyledons * Net veins * Taproot * Flower parts in 4s or 5s Examples: Bean Maple ⸻ Seeds Contain: * Embryo * Stored food * Seed coat Functions: * Protection * Survival * Dispersal ⸻ Seed Dispersal Wind * Dandelion Water * Coconut Animals * Burrs Explosive * Touch-me-not ⸻ Fruit vs Vegetable Fruit: * Comes from ovary * Contains seeds Examples: Tomato Apple Pepper Vegetable: * Root, stem, leaf, or flower Examples: Carrot Celery Broccoli ⸻ Factors Affecting Plant Growth 1. Light 2. Water 3. Carbon dioxide 4. Temperature 5. Soil nutrients 6. Oxygen 7. Soil pH 8. Space 9. Pollinators 10. Disease and pests

Biochem 406 Lecture 21: Ribosome Structure and Translation

Lecture 21: Central Dogma: Ribosome & Protein Synthesis

Translation and the Ribosome Lecture Notes

Biological Translation and Ribosome Function

Eukaryotic Translation: Ribosomes, tRNA, and Protein Synthesis

Ribosomes

MMiPeople Francesco Redi: scientist who tested spontaneous generation with rotting meat and maggot formation with an open container, sealed container, and gauze-covered container, and refuted spontaneous generation Needham: scientist who tested spontaneous generation with boiling chicken broth, sealing the container, and waiting a few days to assess for microbial growth, and supported spontaneous generation Spallanzani: scientist who tested spontaneous generation with further testing, Needham’s experiment, and tested with an open and closed container that was later opened, and refuted spontaneous generation Louis Pasteur: scientist who used swan-neck flasks in his experiment and definitively refuted spontaneous generation Anthony van Leeuwenhoek: scientist who was the first to observe eukaryotic microbes, calling them “wee animalcule” Robert Hooke: coined the term “cell” when looking at cork Matthias Schleiden: observed cells in plant tissue Theodor Schwann: observed cells in animal tissue Rudolf Virchow and Robert Remark: observed cells dividing to make new cells (not mitosis) Hippocrates: suggested disease has natural causes Thucydides: advocated for evidence-based analysis of cause and effect and suggested immunity after observing plague survivors didn't get sick again Marcus Terentius Varro: the first to propose that things we cannot see cause disease Ignaz Semmelweis: physician who observed the spread of disease among patients in different sides of the hospital and instituted hand washing between patients to reduce the spread of disease from patient to patient via healthcare workers Joseph Lister: surgeon who observed post-surgical infection and instituted hand washing and sterilization of medical equipment with 5% phenol solution for less disease Robert Koch: scientist who developed Koch’s postulates to determine the cause of disease and had a rivalry with Louis Pasteur John Snow: questioned the London cholera outbreak and asked questions to the people who had been infected about where they had been and what they had eaten or drank, and noticed that everyone who had cholera used one of two water pumps Classification of microbes What are the 2 domains that are composed of all microbes? Bacteria and Archaea What domain of life is composed only of some microbes? Eukarya What types of microbes do not fit into the domains of life? Viruses and Prions Prions: unicellular organisms in the domains Bacteria and Archaea with no nucleus and have cell walls Viruses: acellular and domainless (not alive) Eukaryotes: unicellular OR multicellular organisms, in domain Eukarya, have a nucleus, have membrane-bound organelles, and include fungi, algae, protazoa, and helminths How many times bigger are bacteria than viruses? 100x A cell is around how many times bigger than an individual bacteria? 10x Cell structures Know the function, general location, and whether they are shared with eukaryotes (if yes similarities/differences) of the following structures: 1. Nucleoid: contains chromosome(s) and nuclear-associated proteins that are usually haploid and circular near the center of the cell, which hold the DNA genetic information without a membrane Eukaryotes = have a nucleus, are diploid and linear Prokaryotes = have nucleoid, are haploid and circular 2. Ribosomes: work with mRNA protein synthesis, made up of proteins and RNA, found in cytoplasm Eukaryotes: 80S, 60 large, 40 small (18S sequencing) Prokaryotes: 70S, 50 large, 30 small (16S sequencing) 3. Cytoplasm: fluid inner layer 4. Fimbriae: short, bristle-like projections for attachment to surfaces 5. Endospores: not all bacteria have, protect bacteria in a dormant state/ harsh environment, found inside bacteria, sporulation = the process of becoming dormant, germination = process of becoming active 6. Plasma membrane: semipermeable, composed of lipids and proteins, controls transport into and out of cell, most inner layer before cytoplasm (ex: facilitated diffusion, active transport, diffusion, endocytosis (Eukaryotes), sterols (Eukaryotes), and cholesterol (Eukaryotes) Same for Eukaryotes 7. Cell wall: protects against harsh changing environments and osmotic stress, contains peptidoglycan in bacteria, contains Gram + and Gram - Steps of Gram stain: dye with crystal violet, iodine (mordant), alcohol (decolorizer), and safranin red If mycobacteria complete an acid-fast stain Gram + has LTA an TA and one membrane Gram - has LPS and 2 membranes 8. Capsule: protective protein shell, outermost layer 9. Pilus: medium projection, adheres to surfaces, does DNA gene transfer 10. Flagellum: long protein projections made of flagellin for movement (ex: 1= monotrichous, one at each end = amphitrichous, many at one end = lophotrichous, many flagella all over the cell = peritrichous 11. Plasmid: circular, double-stranded DNA not part of the chromosome, and can have 1-100 of the same or different plasmids to help with gene transfer, antibiotic resistance, and virulence factors, found anywhere in the cytoplasm Not part of Eukaryotes 12. Inclusion: not all bacteria have, helps with the storage of nutrients and other materials, has protein shell, and is found in cytoplasm (ex: lipid droplets store fats, volutin stores inorganic phosphates, sulfur inclusions store sulfur, gas bubbles store gas for buoyancy in water, magnetosomes store metals for movement) Not part of Eukaryotes; instead, they have vesicles for storage All cellular microbes have what four (4) components? Cell Membrane, Cytoplasm, Ribosomes, and DNA What is the only component of all cells that viruses have? Cytoplasm Know/ be able to identify the shapes of bacteria Round shape: coccus Rod shape: bacillus Vibrio: curved rod shape Short rods with combo of coccus and bacillus: coccobacillus Wavy spiral shape: Spirillum Coiled spiral shape: Spirochete Microbial growth Phases of growth Lag Phase: bacteria gear up for replication by increasing cell size, metabolism, and protein synthesis Log Phase: exponential growth phase, where bacteria actively replicate and are most susceptible to antibiotics Stationary Phase: growth curve flatlines bc bacteria are dying at same rate of growth, begin survival mode and sporulation, produce secondary metabolites, and produce virulence factors, and are low on space, nutrients, and oxygen Death Phase: bacteria die at exponential rate, increase amount of toxic waste, release spores, some spontaneously lyse to feed others, and persister cells refuse to die How do microbes replicate? Through binary fission, fragmentation, budding, and sexually What is a biofilm? Communities of bacteria (steps: colonization, attachment, replication, make EPS with antibiotic resistance, EPS kick bacteria out to replicate somewhere else) How does quorum sensing work? Bacteria want to work together, so they secrete autoinducers, and when you activate enough receptors, they activate a response Growth requirements – classifications and adaptations 1. Oxygen requirements Obligate Aerobes: need O2 to survive Obligate Anaerobes: die in presence of O2 Faculative: mostly need O2 but can survive without it Microaerophiles: need O2 for survival but not atmospheric O2 (low levels) Aerotolerant: can survive with or without oxygen Capnophiles: like high CO2 and low O2 2. pH requirements Acidophiles: low pH (2-4), high H+ environments, efflux pumps to remove H+ ions, changes membrane composition to withstand low pH Neutrophiles: neutral pH (7), found within body Alkaliphiles: basic pH (9-10), modified lipid protein structures, modified electron transport system that use Na+ instead of H+, high OH- environment 3. temperature requirements Psychrophiles: like freezing temperatures a below 0-15 degrees, die at or above 20 degrees, found in cold lakes or the ocean floor, have hydrophobic proteins to increase flexibility, have decreased secondary stabilizing bonds Psychrotolerant: cold not ideal but wont kill them, live between 4-25 degrees (fridge temperature) Mesophiles: moderate temperatures, 20-40 degrees, grow in body Thermophiles: hot environments 50-80 degrees, hot springs, geothermal soil Hyperthermophiles: very hot environments 80-110 degrees, found in hydrothermal vents, increased saturation in membranes, increased stabilizing bonds, alter amino acids to prevent denaturation 4. osmolarity requirements Hypertonic: more water out Hypotonic: more water in Isotonic: equal water in and out Halotolerant: dont require salt but can grow in high salt environments Halophiles: love salt, found in ocean and salt lakes, have increased cytoplasmic glycerol, have efflux pumps for salt 5. barometric requirements Barophile: survive high atmospheric environments like the bottom of the ocean (something at top of mountain has low atmospheric pressure) Microbial Metabolism Means of generating energy (do the processes require oxygen?, which gives the most energy?) Glycolysis: does not require O2 bc it can be used during fermentation, used 2 ATP, makes 4 ATP, NET 2 ATP Kreb’s cycle: requires O2; NET after 1 round= 1ATP, 1 NADH, 1FADH2 (x2 for second round) Electron transport: requires O2, biggest payout of ATP with NET 34 ATP Photosynthesis: does not require O2 as it is a waste product, can do oxygenic and anoxygenic Microbial genetics DNA Replication – enzymes and functions DNA gyrase: unwinds DNA (enzyme) Helicase: unzips DNA (enzyme) Single-stranded binding proteins: bind to DNA so doesnt close back up (protein) Single-stranded binding proteins: bind to DNA so doesnt close back up (protein) DNA polymerase III: lay down new DNA nucleotides, synthesizes leading and lagging strands 5’ →3’(enzyme) DNA polymerase I: removes RNA primers (enzyme) DNA Ligase: seals RNA primers (enzyme) Topoisomerase 4: separates 2 circular chromosomes Transcription and translation – enzymes and function 1. RNA polymerase: turns DNA→ mRNA (transcription) 2. Ribosomes: 30S small, 50S large, 70S total 3. tRNA: A,P, and E sites, bacteria links transcription and translation bc no nucleus, has anticodon at opposite long 3’ end, high energy bond, same active translation process as Eukaryotes Be able to do DNA base pairing, transcription, and translation (given codon table) Also know differences between prokaryotic and eukaryotic Replication, transcription, and translation Genetic Diversity – how does this work? 1. Transformation: uptake of plasmid into different bacteria and is incorporated into its genetic material 2. Transduction: bacteriophage inserts its plasmid into a bacteria (virus that infects a bacteria) 3. Conjugation: like plasmid transfer (ex: rolling circle replication), “bacterial sex” 4

Ribosome Structure and Prokaryotic Translation Initiation

Ribosome Structure, Function, and Translation Practice Flashcards

16S Ribosomal RNA Amplicon Sequencing

Antibiotics Targeting Bacterial Ribosomal Subunits: Mechanisms and Side Effects

Ribosome & Protein Translation: Eukaryotic

Ribosome & Protein Translation: Prokaryotic

Lecture 21: The Ribosome & Protein Synthesis

Ribosomal Initiation, Elongation, and Termination Factors in Protein Synthesis

Objectives come from your Unit 3 sheet  and the content/examples come from the PowerPoints . ⸻ UNIT 3 COMPLETE STUDY GUIDE (Based strictly on your slides + objectives) ⸻ CHAPTER 11 — CONTROLLING MICROBIAL GROWTH Difference Between Antisepsis, Disinfection, Sanitization, Sterilization, Degerming, Decontamination Sterilization Complete destruction of all microbial life including viruses and endospores. Examples from slides: • Surgical instruments • Syringes • Packaged foods Endospores must be destroyed for something to be considered sterile.  ⸻ Disinfection Destroys most vegetative pathogens on nonliving surfaces. Examples: • Disinfecting medical equipment • Hospital surfaces ⸻ Antisepsis Use of antimicrobial chemicals on living tissue. Examples: • Skin prep before surgery • Cleaning wounds ⸻ Degerming Mechanical removal of microbes by scrubbing. Example: • Handwashing ⸻ Sanitization Reduces microbial numbers to public health safe levels. Examples: • Cleaning food preparation surfaces • Restaurant sanitation ⸻ Decontamination General removal of microbes from objects or surfaces. Example: • Cleaning contaminated hospital equipment ⸻ Difference Between Static and Cidal Cidal Kills microbes. Example Bactericidal antibiotics. ⸻ Static Stops growth but does not kill. Example Bacteriostatic antibiotics. ⸻ Variables That Influence Effectiveness of Antimicrobial Methods 1. Population size Large populations require more time to kill. 2. Nature of microbes Some microbes are more resistant. Example: Bacterial endospores. 3. Temperature Higher temperature increases killing. 4. Concentration of agent 5. Contact time 6. Organic matter present Example: Blood or mucus interfering with disinfectants. 7. Mode of action of agent 8. Biofilms Biofilms protect microbes from antimicrobials.  ⸻ Most Resistant vs Least Resistant Microbes Most resistant: Bacterial endospores Reason: Thick protective layers. ⸻ Less resistant: • Mycobacteria • Gram-negative bacteria • Gram-positive bacteria • Fungi • Viruses Endospores are the target of sterilization methods.  ⸻ Mechanisms of Antimicrobial Agents Agents work by damaging: Cell wall Example Detergents and alcohol disrupt cell wall. ⸻ Cell membrane Effects • Loss of permeability • Leakage of molecules ⸻ Proteins Agents denature proteins. Examples • Heat • Alcohol • Strong acids ⸻ DNA and RNA Example Radiation damaging DNA. ⸻ Practical Concerns When Choosing Control Method Consider: • Does item require sterilization or disinfection? • Can item tolerate heat, pressure, radiation, chemicals? • Cost effectiveness • Safety • Ability of agent to penetrate surfaces.  ⸻ PHYSICAL AND MECHANICAL METHODS ⸻ Pasteurization vs Sterilization Pasteurization: Reduces microbial numbers but does not sterilize. Used for: Milk and beverages. Sterilization: Destroys all microbes including endospores. ⸻ Boiling Kills many pathogens but may not destroy endospores. ⸻ Autoclaving Uses steam under pressure. Conditions from slides: 121°C 15 minutes 15 psi Mechanism: Denatures proteins and disrupts metabolism.  ⸻ Most Rigorous Heat Method Incineration (dry heat) Burns microbes completely. ⸻ Ionizing Radiation vs UV Radiation Ionizing radiation Examples: Gamma rays X-rays Effect: Destroys DNA and proteins. Highly penetrating. ⸻ UV radiation Example: Germicidal lamps. Mechanism: Forms pyrimidine dimers (thymine dimers). Effect: DNA replication blocked.  ⸻ Filtration Removes microbes from liquids or air. Examples: • Water purification • Milk filtration • Air filtration systems • HEPA filters • N95 masks HEPA filters remove 99.97% of particles.  ⸻ Osmotic Pressure High salt or sugar removes water from microbes. Examples: Salt: Cured meats Sugar: Jams and jellies Causes plasmolysis and prevents growth.  ⸻ Cold and Drying Cold: Slows microbial metabolism but rarely kills microbes. Drying (desiccation): Removes water necessary for microbial metabolism. Example: Freeze drying (lyophilization).  ⸻ CHEMICAL METHODS ⸻ Characteristics of Good Chemical Antimicrobials • Rapid action • Effective at low concentrations • Broad spectrum • Stable • Non-toxic to tissues • Affordable • Effective in presence of organic matter  ⸻ Major Chemical Agents ⸻ Halogens Examples: • Chlorine • Iodine Common example: Household bleach (sodium hypochlorite) Mechanism: Oxidizes cellular molecules and damages enzymes.  ⸻ Phenols Mechanism: Disrupt cell membranes and denature proteins. Examples: Phenolic disinfectants. ⸻ Alcohols Examples: • Ethanol • Isopropanol Mechanism: Denature proteins and disrupt membranes. Common use: Hand sanitizers. ⸻ Quats Quaternary ammonium compounds. Mechanism: Disrupt membranes. Example: Lysol wipes ⸻ Peroxides Example: Hydrogen peroxide. Mechanism: Forms reactive oxygen molecules that damage cells. ⸻ Detergents / Surfactants Mechanism: Break down lipid membranes. Examples: Soap and cleaning detergents.  ⸻ CHAPTER 12 — ANTIBIOTICS ⸻ Alexander Fleming Discovered penicillin in 1928 from the fungus Penicillium.  ⸻ Characteristics of a Good Antimicrobial Drug • Selective toxicity • High therapeutic index • Targets unique microbial structures • Effective against pathogen • Minimal harm to microbiota  ⸻ Selective Toxicity Ability of a drug to kill microbes without harming host cells. Example: Penicillin targets bacterial cell walls, which human cells lack. ⸻ Susceptibility Tests ⸻ Kirby-Bauer Disc diffusion test. Antibiotic discs placed on bacterial culture. Zone of inhibition measured. Results: Sensitive Resistant  ⸻ MIC Minimum inhibitory concentration. Smallest drug concentration preventing visible growth. ⸻ MBC Minimum bactericidal concentration. Smallest concentration that kills bacteria. ⸻ Therapeutic Index TI = toxic dose / therapeutic dose Example from slides: TI of 10 safer than TI of 1.1.  ⸻ Antibiotic Mechanisms ⸻ Cell Wall Inhibitors Example: Penicillin Mechanism: Prevents cross-linking of NAM-NAG peptidoglycan. Cell bursts due to osmotic pressure. Other examples: • Methicillin • Cephalosporins  ⸻ Cell Membrane Disruption Examples: • Polymyxin • Daptomycin • Colistin Mechanism: Creates pores causing leakage.  ⸻ Protein Synthesis Inhibitors Example: Tetracycline Mechanism: Blocks 30S ribosomal subunit. Other examples: • Erythromycin • Azithromycin • Chloramphenicol  ⸻ DNA / RNA Inhibitors Example: Fluoroquinolones Examples: • Ciprofloxacin • Levofloxacin Mechanism: Inhibit DNA gyrase. ⸻ Metabolic Pathway Inhibitors Example: Sulfa drugs Block folic acid synthesis. Example drug: Bactrim.  ⸻ Drugs for Eukaryotic Pathogens ⸻ Antifungals Examples: • Fluconazole • Amphotericin B • Azoles Target ergosterol in fungal membranes. ⸻ Antiprotozoal Drugs Examples: • Metronidazole • Chloroquine ⸻ Antihelminthic Drugs Examples: • Pyrantel • Mebendazole • Ivermectin  ⸻ Antiviral Drugs Targets: • Viral attachment • Viral transcription/translation • Viral assembly or release Examples: Acyclovir Blocks viral DNA replication. Tamiflu Prevents influenza virus release.  ⸻ HIV Drugs Target steps in HIV replication: 1 Reverse transcriptase 2 Integrase 3 Protease 4 Viral attachment Combination therapy prevents resistance. ⸻ Antibiotic Resistance ⸻ How Resistance Develops • Mutation • Natural selection • Overuse of antibiotics ⸻ Mechanisms of Resistance • Drug-destroying enzymes • Efflux pumps • Target modification • Reduced permeability  ⸻ CHAPTER 13 — MICROBIOTA ⸻ Normal Microbiota Microorganisms living on body surfaces without causing disease. Examples from slides: Skin: Staphylococcus epidermidis Gut: Escherichia coli Breast milk microbes: • Bifidobacterium • Lactobacillus • Streptococcus • Clostridium  ⸻ Benefits of Microbiota • Produce vitamins • Digest food • Stimulate immune system • Produce neurotransmitters • Prevent pathogen colonization  ⸻ Dysbiosis Imbalance in microbiota. Associated diseases: • Diabetes • Obesity • Cancer • Asthma • Allergies • Heart disease  ⸻ Microbiota Development Microbiota develop: 1 During birth 2 Through breast milk 3 Environmental exposure Stable microbiome forms by age 3. ⸻ Probiotics vs Prebiotics Probiotics: Live microbes that improve microbiota. Example: Yogurt. ⸻ Prebiotics: Food that feeds beneficial microbes. Examples: • Garlic • Onions • Asparagus • Agave • Artichokes  ⸻ Fecal Microbiota Transplant Transfer of microbiota from healthy donor. Used for: Clostridioides difficile infections Success rate: 70–90%.  ⸻ Virulence Factors Examples: Adhesion structures: Capsules, fimbriae Exoenzymes: Hyaluronidase Coagulase Biofilms increase resistance.  ⸻ Toxins ⸻ Exotoxins Secreted protein toxins. Examples: • Cytotoxins • Neurotoxins • Enterotoxins ⸻ Endotoxins Found in gram-negative bacteria. Example: LPS containing lipid A. Effects: • Fever • Inflammation • Shock  ⸻ CHAPTER 14 — EPIDEMIOLOGY ⸻ Epidemiology Study of disease frequency, distribution, and control in populations.  ⸻ Epidemiological Terms Index case: First identified patient. Incidence: Number of new cases. Prevalence: Total existing cases. Mortality rate: Deaths in a population. Case fatality rate: Deaths among infected individuals.  ⸻ Disease Occurrence Sporadic: Random cases. Endemic: Constant presence. Outbreak: Localized increase. Epidemic: Large regional increase. Pandemic: Worldwide epidemic.  ⸻ Healthcare-Associated Infections (HAIs) Common examples: • CAUTI Catheter-associated urinary tract infection • CLABSI Central line bloodstream infection • Surgical site infections • Ventilator associated infections  ⸻ Causes of HAIs • Low patient immunity • Antibiotic resistant organisms • Invasive procedures • Healthcare worker transmission Example: Healthcare workers moving between patients.  ⸻ Prevention of HAIs • Medical asepsis • Surgical asepsis • Universal precautions • Infection control officers Examples: • Needlestick precautions • Surface decontamination • Barrier protection  ⸻ If you want, I can also give you the 20–30 questions your professor is MOST likely to put on the exam from these slides. Micro professors tend to repeat the same exact conceptual questions every semester, and your slides have some really obvious ones.

BCH311 L11 Ribosome, protein synthesis