Biology Review

Unit 2 Biochemistry

• 2.2 Bimoleucles

  • Food is a source of large molecules that are needed for life call BIOMOLECULES

• Also known as Macromolecules:

  • Carbohydrates

  • Lipids

  • Proteins

  • Nucleic Acid

• Peanut Butter can be high in Protein and Lipids

• Monomer: Building block

  • Usually referring to same type of “block” that makes up something larger

• Carbohydrates: Energy

  • Food sources like: bread, pasta, fruit, and vegetable tend to be high in carbohydrates

• Monomer: Monosaccharide

• Ex: Sugar Glucose

• Carbohydrate = -ose

  • Glucose

  • Maltose

  • Lactose

  • Sucrose

  • Fructose

• COmbining alot of monosacchride = Polysaccharide

• Lipids: fats and oils / Energy storage

  • Food sources like: butter or olive oil

  • Other lipids: Triglycerides, steriods, Phospholipids

• Proteins:

  • Food source like: beans, meat, nuts, and eggs,

  • Monomer: Amino Acids

  • Tissues like muscle tissue consist heavily of proteins,

  • Proteins create hair, collagen

  • Most enzymes can build up or break down substances

• Nucleic Acid:

  • Include DNA and RNA

  • Monomer: Nucleotide

• Carbohydrate - CHO

• Lipids - CHO

• Protein - CHON

• Nucleic Acid - CHONP

  • C - Carbon

  • H - Hydrogen

  • O - Oxygen

  • N - Nitrogen

  • P - Phosphorus

• 2.3 Enzymes

  1. Protein

  2. Catalyze

  3. Shape matters

  4. Re-usable

  5. Denatured by pH and Temperature

Unit 3 Cells

🧪 1. Cell Theory

Amoeba Sisters Video: “Cell Theory”

Three Main Tenets of Cell Theory:

1. All living things are composed of cells.

2. Cells are the basic unit of structure and function in living organisms.

3. All cells come from pre-existing cells.

Modern Additions to the Cell Theory:

• Energy flow occurs within cells.

• Cells contain hereditary information (DNA) that is passed during cell division.

• All cells are basically the same in chemical composition in organisms of similar species.

Key Scientists:

• Robert Hooke: First to coin the term “cell.”

• Anton van Leeuwenhoek: Observed living cells (bacteria and protists).

• Schleiden & Schwann: Declared all plants and animals are made of cells.

• Virchow: Proposed that all cells come from existing cells.

🧬 2. Prokaryotes vs. Eukaryotes

Amoeba Sisters Video: “Prokaryotic vs. Eukaryotic Cells”

Key Reminder: All cells (prokaryotic or eukaryotic) have:

• Cell membrane

• Cytoplasm

• DNA

• Ribosomes

🔬 3. Microbiology Lab

Common Lab Tools:

• Microscope – observe cells and microscopic organisms.

• Petri dishes and agar – grow bacterial cultures.

• Sterile swabs & loops – collect and transfer samples.

• Stains (e.g., methylene blue, Gram stain) – highlight cell structures.

Safety Procedures:

• Wear gloves, goggles, lab coats.

• Always sterilize before and after handling specimens.

• Dispose of biohazards properly.

🧫 4. Organelles & Cell Structures

Amoeba Sisters Video: “Cell Organelles”

Key Organelles and Their Functions:

🌟 5. Cell Adaptations

Definition: Structural features that help a cell perform its function efficiently.

Examples:

🧠 6. Cell Specialization (Differentiation)

Amoeba Sisters Video: “Cell Differentiation”

How It Works:

• All cells start as stem cells with the full set of DNA.

• As cells develop, certain genes are turned on or off depending on the cell's function.

• This process is called gene expression.

• Leads to specialized cells like skin cells, muscle cells, etc.

Key Terms:

• Stem Cell: An unspecialized cell that can become other cell types.

• Differentiation: The process where a cell becomes specialized.

Unit 4 Cellular Processes

🏠 1. Cell Homeostasis

Amoeba Sisters Video: “Homeostasis”

Definition:

Homeostasis is the ability of a cell (or organism) to maintain stable internal conditions despite changes in the external environment.

How Cells Maintain Homeostasis:

• Cell membrane controls what enters and exits.

• Transport proteins move substances across the membrane.

• Feedback mechanisms regulate processes like temperature, pH, glucose levels.

Examples in Cells:

• Osmoregulation: Water balance via osmosis.

• Glucose regulation: Insulin signals cells to take in glucose.

• Thermoregulation: Enzymes only function within a narrow temperature range.

🔁 2. Cell Transport

Amoeba Sisters Video: “Cell Transport”

🟢 Types of Cell Transport:

✅ Passive Transport (no energy required)

Substances move from high to low concentration (down the gradient).

🔴 Active Transport (requires ATP energy)

Moves substances from low to high concentration (against the gradient).

🌊 Osmosis and Tonicity:

⚡ 3. Cell Energy (ATP, Photosynthesis, Respiration)

Amoeba Sisters Videos:

• “ATP: The Energy Currency”

• “Photosynthesis and Cellular Respiration”

🔋 ATP: Adenosine Triphosphate

• Main energy molecule for cells.

• Energy is released when a phosphate group is broken off → becomes ADP.

🌿 Photosynthesis

Occurs in: Chloroplasts of plant cells
Purpose: Convert sunlight into chemical energy (glucose)

Equation:

6CO2+6H2O+light→C6H12O6+6O2\text{6CO}_2 + 6H_2O + \text{light} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6O_26CO2​+6H2​O+light→C6​H12​O6​+6O2​

• Reactants: Carbon dioxide, water, light

• Products: Glucose, oxygen

🔥 Cellular Respiration

Occurs in: Mitochondria of both plants and animals
Purpose: Break down glucose to release energy (ATP)

Equation:

C6H12O6+6O2→6CO2+6H2O+ATP\text{C}_6\text{H}_{12}\text{O}_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}C6​H12​O6​+6O2​→6CO2​+6H2​O+ATP

• Reactants: Glucose, oxygen

• Products: Carbon dioxide, water, ATP

Types of Respiration:

Unit 5 Deoxyribonucleic Acid

🧬 1. DNA History

Amoeba Sisters Video: “The Discovery of DNA”

🧠 Key Scientists:

🧬 2. DNA Structure

Amoeba Sisters Video: “DNA Structure and Function”

📎 DNA Basics:

• Full name: Deoxyribonucleic Acid

• Shape: Double helix (twisted ladder)

• Monomer: Nucleotide

🧱 Nucleotide Structure:

1. Phosphate group

2. Deoxyribose sugar

3. Nitrogen base

🧬 Nitrogen Base Pairs (Chargaff’s Rule):

• A pairs with T (2 hydrogen bonds)

• C pairs with G (3 hydrogen bonds)

🔁 3. DNA Replication

Amoeba Sisters Video: “DNA Replication”

⚙ Key Concepts:

• Occurs in the nucleus during the S phase of interphase.

• Purpose: To make an exact copy of DNA before cell division.

🧬 Steps:

1. Helicase unzips the DNA (breaks hydrogen bonds).

2. DNA polymerase adds complementary nucleotides (A-T, C-G).

3. Two identical DNA strands form—semi-conservative replication (each has one original strand and one new strand).

🔄 4. Protein Synthesis

Amoeba Sisters Video: “Protein Synthesis”

🧪 Overview:

Protein synthesis = Transcription + Translation

✍ Transcription (in the nucleus)

• DNA → mRNA

• Enzyme: RNA polymerase

• mRNA uses U instead of T (A-U, C-G)

🌐 Translation (at the ribosome)

• mRNA → protein

• tRNA brings amino acids to ribosome.

• Each codon (3 bases) on mRNA codes for one amino acid.

🔠 5. Codon Charts

🧬 Codons:

• 3-letter sequences on mRNA.

• Start codon: AUG (codes for methionine)

• Stop codons: UAA, UAG, UGA

🧪 How to Use a Codon Chart:

1. Use the mRNA codon, not DNA or tRNA.

2. Match the codon to its amino acid.

Example:

• DNA: TAC → mRNA: AUG → Protein: Methionine (start)

💥 6. Mutations

Amoeba Sisters Video: “Mutations”

🧬 Types of Mutations:

🔍 Effects:

• Some are neutral, harmful, or beneficial.

• Mutations in sex cells (sperm/egg) can be passed on.

🧫 7. DNA Technology

Amoeba Sisters Video: “DNA Technology”

🧪 Common Techniques:

Unit 6 Cell DIvision

🔄 1. Cell Cycle

Amoeba Sisters Video: “The Cell Cycle and Cancer”

📆 Phases of the Cell Cycle:

🧠 Key Point:

• Most of a cell’s life is spent in interphase.

🧬 2. Mitosis

Amoeba Sisters Video: “Mitosis: The Amazing Cell Process”

🔬 Purpose:

• Growth, repair, and asexual reproduction

• Produces 2 identical daughter cells (diploid, 2n)

🧬 Mitosis Phases (PMAT):

➗ Cytokinesis:

• Animals: Cleavage furrow pinches in.

• Plants: Cell plate forms a new wall.

🛑 3. Cell Regulation

Amoeba Sisters Video: “The Cell Cycle and Cancer”

⚖ Regulation:

• Checkpoints monitor the cell cycle.

• Cyclins and enzymes control progression.

• If something’s wrong, the cell can go into apoptosis (programmed death).

❌ Cancer:

• Uncontrolled cell division due to mutation in regulatory genes (like tumor suppressors).

• Cancer cells ignore signals to stop dividing and can form tumors.

🔁 4. Types of Reproduction

Amoeba Sisters Video: “Asexual vs. Sexual Reproduction”

🧪 Examples:

• Asexual: Binary fission, budding, mitosis in body cells.

• Sexual: Meiosis + fertilization → zygote.

🌱 5. Meiosis

Amoeba Sisters Video: “Meiosis: The Great Divide”

🎯 Purpose:

• Form gametes (sperm/egg) for sexual reproduction.

• Produces 4 genetically different haploid (n) cells.

🔢 Meiosis Summary:

• 1 cell → 4 non-identical gametes

• Chromosome number halved (diploid → haploid)

• In humans: 46 → 23 chromosomes

🧬 Meiosis Stages (Meiosis I & II):

Meiosis I:

• Prophase I: Crossing over (exchange of genetic material) → genetic diversity

• Metaphase I: Homologous chromosomes line up in pairs.

• Anaphase I: Homologous pairs pulled apart.

• Telophase I & Cytokinesis: Two haploid cells form.

Meiosis II:

• Same steps as mitosis (PMAT), but starts with 2 haploid cells → ends with 4 haploid cells.

Unit 7 Genetics

🧬 1. Introduction to Genetics

Amoeba Sisters Video: “Introduction to Heredity”

🧠 Key Concepts:

• Genetics: Study of heredity (how traits are passed from parents to offspring).

• Gene: A segment of DNA that codes for a trait.

• Allele: Different versions of a gene (e.g., blue vs. brown eyes).

• Genotype: The genetic makeup (e.g., Bb, bb).

• Phenotype: The physical trait expressed (e.g., brown eyes).

• Homozygous: Two identical alleles (BB or bb).

• Heterozygous: Two different alleles (Bb).

🌱 2. Mendelian Genetics

Amoeba Sisters Video: “Mendelian Genetics”

🧬 Gregor Mendel:

• Father of genetics

• Studied pea plants to understand dominant and recessive traits.

🧪 Mendel’s Laws:

🧮 Punnett Square Example:

• B = brown eyes, b = blue eyes

• Parent genotypes: Bb x Bb

• Results: 75% brown eyes (BB, Bb), 25% blue eyes (bb)

🌈 3. Non-Mendelian Genetics

Amoeba Sisters Video: “Non-Mendelian Inheritance”

🧬 4. Human Genetic Disorders

Amoeba Sisters Video: “Mutations and Genetic Disorders”

💡 Vocabulary:

• Autosomal: On chromosomes 1–22 (not X/Y)

• Nondisjunction: Chromosomes fail to separate during meiosis → genetic disorders

🧬 5. Pedigrees

Amoeba Sisters Video: “Pedigrees”

🔍 What is a Pedigree?

A diagram that shows how traits are inherited through a family.

♀♂ Symbols:

• Square = Male

• Circle = Female

• Shaded = Affected

• Half-shaded = Carrier (recessive)

• Horizontal line = Mating

• Vertical line = Offspring

🧬 Interpreting Inheritance:

🧪 6. Karyotypes

Amoeba Sisters Video: “Chromosomes and Karyotypes”

📊 What Is a Karyotype?

A picture of all the chromosomes in a cell arranged in pairs (used to detect abnormalities).

🧬 How to Analyze:

• Humans have 23 pairs (46 total).

• Pair 23 = sex chromosomes (XX = female, XY = male).

• Look for extra or missing chromosomes (e.g., Trisomy 21 = Down Syndrome)

Unit 8 Evolution

🧬 1. History of Evolution

Amoeba Sisters Video: “Natural Selection and Adaptations”

🌍 Key Scientists:

🦎 Natural Selection:

• Variation exists in populations

• Struggle to survive (competition)

• Some traits increase fitness

• These traits get passed on more often

👥 2. Populations and Evolution

Amoeba Sisters Video: “Population Genetics and Evolution”

🧠 Terms to Know:

• Gene pool: All the alleles in a population

• Genetic drift: Random change (bottleneck/founder effects)

• Gene flow: Movement of genes in/out of a population

• Mutation: Source of variation

• Natural selection: Favors certain traits

📊 Types of Selection:

🧫 3. Immunology

Amoeba Sisters Video: “Immune System”

🛡 Immune System Overview:

• First line: Skin, mucus, stomach acid

• Second line: Inflammatory response (nonspecific)

• Third line: Specific immune response (antibodies, memory cells)

🔑 Cells & Terms:

🧠 4. Evidence for Evolution

Amoeba Sisters Video: “Evidence for Evolution”

🔍 Types of Evidence:

🧬 5. Classification

Amoeba Sisters Video: “Classification”

🔢 Taxonomic Levels:

(Dear King Philip Came Over For Great Spaghetti)
Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species

• Organisms are grouped by shared characteristics and DNA similarities.

• Binomial nomenclature: Genus + species (e.g., Homo sapiens)

🌳 6. Cladograms & Dichotomous Keys

Amoeba Sisters Videos: “Cladograms” and “Dichotomous Keys”

🧬 Cladogram:

• A branching diagram showing evolutionary relationships

• Closer branches = more closely related

• Shared derived traits appear along the branches

Example:

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┌───Lizard ───┤ └─┬───Bird └───Mammal

Bird and mammal share a more recent ancestor than with lizard.

🔎 Dichotomous Key:

• Series of paired statements used to identify organisms

• You follow the path based on observable traits

Example:
1a. Has feathers → go to 2
1b. No feathers → go to 3
2a. Cannot fly → Ostrich
2b. Can fly → Robin

Unit 9 Ecology

🌿 1. Interrelationships in Ecosystems

Amoeba Sisters Video: “Ecosystem Ecology”

🌎 Key Terms:

🧬 Types of Species Interactions:

🔥 2. Energy Flow in Ecosystems

Amoeba Sisters Video: “Food Webs and Energy Pyramids”

🔗 Food Chains & Webs:

• Producers (autotrophs): Make own food (plants, algae)

• Consumers (heterotrophs): Eat others

  • Primary (herbivores) → Secondary (carnivores) → Tertiary (top predators)

• Decomposers: Break down dead material (fungi, bacteria)

🔺 Energy Pyramid:

• Only ~10% of energy is passed to the next level

• Energy is lost as heat

🔁 3. Cycling of Matter

Amoeba Sisters Video: “Biogeochemical Cycles”

🌧 Water Cycle:

• Evaporation → Condensation → Precipitation → Runoff/Infiltration

🌿 Carbon Cycle:

• Photosynthesis: CO₂ → glucose

• Respiration: glucose → CO₂

• Burning fossil fuels increases atmospheric CO₂

🧬 Nitrogen Cycle:

• Nitrogen-fixing bacteria convert nitrogen into usable forms for plants

• Decomposers return nitrogen to soil

• Lightning also fixes nitrogen

👥 4. Population Dynamics

Amoeba Sisters Video: “Population Ecology”

📈 Factors Affecting Populations:

🧮 Carrying Capacity:

• Max number of individuals ecosystem can support

• Limiting factors determine capacity

📊 Growth Patterns:

🌱 5. Adaptations of Plants & Animals

Amoeba Sisters Video: “Natural Selection and Adaptations”

🧠 Types of Adaptations:

🌿 Plants:

• Waxy cuticle to reduce water loss

• Deep roots for water access

• Thorns for defense

🐾 Animals:

• Camouflage, mimicry, thick fur, webbed feet

🌍 6. Human Impact on the Environment

Amoeba Sisters Video: “Human Impact”

🌪 Negative Impacts:

✅ 7. Sustainable Practices

Amoeba Sisters Video: “Sustainability”

🌿 Sustainability Means:

Meeting today’s needs without compromising future generations

♻ Examples: