Untitled Flashcards Set

Key Terms:

Hypothesis: A testable prediction or educated guess about the outcome of an experiment.

Observation:  Using your senses to gather information about the world around you.

Fact : an observation that is consistently confirmed and can be proven true.

Theory : A well-tested explanation of an aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses.

Law: A statement that describes a consistently observed phenomenon, often expressed mathematically (e.g., Newton's Laws).

Experimental Design: IMPORTANT

Independent Variable :The variable that is changed or manipulated in the experiment. The thing I’M manipulating

Dependent Variable:The variable that is measured or observed as it responds to changes in the independent variable, the thing that happpens.

Control Group: The group in an experiment that does not receive the thing (independent variable) and is used for comparison.

Experimental Group: The group that is exposed to the independent variable.

Constants: Variables that are kept the same across all groups in the experiment.

Data Collection:

Quantitative Data: Numerical data (e.g., height, weight, temperature).

Qualitative Data: Descriptive data (e.g., color, texture, behavior).

Final Notes: Experiment Conclusions

When writing a conclusion for an experiment, include the following elements:

- Restate the Hypothesis: Briefly restate your original hypothesis and state whether the results support or contradict it.

- Summarize the Results:  Discuss the findings and any patterns or trends observed.

- Interpret the Results:Provide an analysis of the data. Did the results match expectations? If not, why might that be?

- Possible Errors: Acknowledge any limitations or sources of error in the experiment that may have affected the results.

- Suggestions for Future Research: Offer ideas for improving the experiment or questions for further investigation.

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Biochemistry: Chapter 2

Chemical Bonds:

- Covalent Bond: Atoms share electrons.

- Ionic Bond: Atoms transfer electrons (one gains, one loses).

- Hydrogen Bond: Weak attraction between a hydrogen atom and an electronegative atom (e.g., in water molecules).

Octate rule- Outer shells must have 8 electrons

Water Properties:

Cohesion: Water molecules stick to each other.

- Adhesion: Water molecules stick to other surfaces.

-Surface Tension: The surface of water resists external force, it creates sort of a web. Like skipping rocks

- Polarity: Water has a partial positive charge on hydrogen and a partial negative charge on oxygen.

-H20

Biological Molecules:

- Carbohydrates: Breads,wheat. Purpose to store and release  short term energy

- Monomer: Monosaccharides (e.g., glucose), Disachardie

- Polymer: Polysaccharides (e.g., starch).

- Lipids: Store energy , long term

- Monomer: Fatty acids

- Polymer: unsaturated and saturated fatty acids

- Proteins: They do cell structure and regulation

  - Monomer: Amino acids.

  -Polymer: proteins.

- Nucleic Acids: store genetic information

  - Monomer: Nucleotides.

  - Polymer: nucleic acid

-expample:dna and rna

Enzymes: ENDS IN -ASE

-Increases the speed of chemical reactions and lower activation energy

- Substrate: The molecule that an enzyme acts on.

- Active Site: The specific region on the enzyme where the substrate binds.

- Specificity: Each enzyme is specific to a particular substrate due to its unique active site shape.

Enzyme substrate complex

Factors Affecting Enzyme Functions:

  - Temperature: Enzymes work best at a specific temperature. Too high or low can denature the enzyme, which basically deforms the ‘lock’

  What can influence this?

-fever

-ph level

Cellular Energy: Chapters 9 & 10

Photosynthesis:

Purpose: To convert light energy into chemical energy stored in glucose, which is used by plants for growth and energy.

Cells: Chapter 8

Organelles and Functions:

- Nucleus: Contains (DNA) and controls cell activities.

- Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for delivery, AMAZON WORKHOUSE

- Mitochodnria: Powerhouse of the cell, site of cellular respiration. Makes ATP

- Chloroplast: Site of photosynthesis in plant cells.

- Ribosomes: Assembly of  proteins.

- Rough Endoplasmic Reticulum: Has ribosomes; makes proteins.

- Smooth Endoplasmic Reticulum; Synthesizes lipids and detoxifies chemicals.

- Vacuoles: Stores nutrients, water.

- Vesicles: Transport materials within the cell. VEICHLE

- Cytoplasm: Glue inside the cell

- Cell Membrane: Regulates what enters and leaves the cell; provides structure.

- Cell Wall: (plant cells): Provides additional structure and protection.

- Cytoskeleton: Supports cell shape

Differences:

- Plant Cells vs Animal Cells:

Plant cells have a cell wall, chloroplasts, and a large  vacuole.

-Eukaryotic vs Prokaryotic Cells**:

Eukaryotes have membrane-bound organelles (e.g., nucleus), while prokaryotes do not.

Cell Membrane:

- Structure: Composed of a phospholipid bilayer with embedded proteins.

- Semi-Permeable:                   It allows certain molecules to pass through while blocking others.

Cell Transport:

- Passive Transport: Movement of molecules without energy (e.g., diffusion, osmosis).

- Active Transport : Movement of molecules requiring energy NEEDS ATP

-Facilitated defussion: diffusion that needs help (osmosis)

-Isotonic: Equal concentration of solutes inside and outside the cell.

-Hypotonic *: Lower concentration of solutes outside the cell (cell may swell). ENDOCYTOSIS

- hypertonic : Higher concentration of solutes outside the cell (cell may shrink). EXCOTOSIS

-Organelle: Chloroplast is the organelle where photosynthesis occurs.

Chemical Equation:

  6CO2 + 6H2O + light rightarrow C6H{12}O6 + 6O2

-Stages of Photosynthesis:

  1. Light Reactions (occur in the thylakoid membranes of the chloroplast):

     Reactants: Light, water

    Products: Oxygen, ATP, NADPH

  2. Calvin Cycle(occur in the stroma of the chloroplast):

     - Reactants: CO2, ATP, NADPH

     - Products: Glucose

- Water in Photosynthesis: Water is split to release oxygen during the light reactions.

- Electron Carriers: NADPH and ATP.

- Pigment: Chlorophyll, which absorbs light energy to power photosynthesis.

#### Cellular Respiration:

- Purpose: To convert chemical energy stored in glucose into ATP, the usable energy for cells.

- Stages of Cellular Respiration:

  1. Glycolysis (occurs in the cytoplasm):

     - Reactants: Glucose

     - Products: 2 Pyruvate, 2 ATP, 2 NADH

  2. Citric Acid Cycle (Krebs Cycle) (occurs in the mitochondria):

     - Reactants: Pyruvate, oxygen

     - Products: CO2, ATP, NADH, FADH2

  3. Electron Transport Chain (occurs in the mitochondria):

     - Reactants: NADH, FADH2, oxygen

     - Products: ATP, H2O

- Electron Carriers: NADH, FADH2.

- Fermentation:

  1. Lactic Acid Fermentation: Produces lactic acid and 2 ATP.

  2. Alcoholic Fermentation: Produces alcohol (ethanol) and 2 ATP (used in yeast fermentation).

- Aerobic vs Anaerobic Respiration:

  - Aerobic: Requires oxygen, produces more ATP.

  - Anaerobic: Does not require oxygen, produces less ATP.

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### Cells: Chapter 8

#### Organelles and Functions:

- Nucleus: Contains genetic material (DNA) and controls cell activities.

- Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for delivery.

- Mitochondria: Powerhouse of the cell, site of cellular respiration.

- Chloroplast: Site of photosynthesis in plant cells.

- Ribosomes: Synthesize proteins.

- Rough Endoplasmic Reticulum: Has ribosomes; makes proteins.

- Smooth Endoplasmic Reticulum: Synthesizes lipids and detoxifies chemicals.

- Vacuoles: Stores nutrients, water, and waste products.

- Vesicles: Transport materials within the cell.

- Cytoplasm: Gel-like substance where cell activities occur.

- Cell Membrane: Regulates what enters and leaves the cell; provides structure.

- Cell Wall (plant cells): Provides additional structure and protection.

- Cytoskeleton: Supports cell shape, movement, and organization.

#### Differences:

- Plant Cells vs Animal Cells: Plant cells have a cell wall, chloroplasts, and a large vacuole.

- Eukaryotic vs Prokaryotic Cells: Eukaryotes have membrane-bound organelles (e.g., nucleus), while prokaryotes do not.

#### Cell Membrane:

- Structure: Composed of a phospholipid bilayer with embedded proteins.

- Semi-Permeable: It allows certain molecules to pass through while blocking others.

#### Cell Transport:

- Passive Transport: Movement of molecules without energy (e.g., diffusion, osmosis).

- Active Transport: Movement of molecules requiring energy (e.g., sodium-potassium pump).

- Isotonic: Equal concentration of solutes inside and outside the cell.

- Hypotonic: Lower concentration of solutes outside the cell (cell may swell).

- Hypertonic: Higher concentration of solutes outside the cell (cell may shrink).

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Cell Division & Genetics: Chapters 11, 12, 15

The Cell Cycle:

- Stages

  1. Interphase: G1 (growth), S (DNA replication), G2 (preparation for mitosis).

  2. Mitosis: Prophase, Metaphase, Anaphase, Telophase.

  3. Cytokinesis: Division of the cytoplasm.

Mitosis Stages:

- Prophase : Chromosomes condense, nuclear membrane dissolves.

- Metaphase :Chromosomes line up in the middle.

- Anaphase: Chromosomes are pulled apart.

- Telophase: Nuclear membranes re-form around each set of chromosomes.

End Result of Mitosis: Two genetically identical daughter cells, each with the same number of chromosomes as the parent cell.

Meiosis:

Cell Division & Genetics: Chapters 11, 12, 15 (Continued)

#### Meiosis:

- Prophase I: Homologous chromosomes pair up and exchange genetic material through crossing over. This is important because it increases genetic diversity by creating new combinations of alleles.

- Metaphase I: Homologous chromosomes align at the cell's equator.

- Anaphase I: Homologous chromosomes are separated and pulled to opposite poles.

- Telophase I: The chromosomes reach opposite ends, and two new nuclear membranes form. The cell divides into two daughter cells.

- Meiosis II: Similar to mitosis, but without DNA replication:

  - Prophase II: Chromosomes re-condense.

  - Metaphase II: Chromosomes align in the center.

  - Anaphase II: Sister chromatids are separated.

  - Telophase II: Four non-identical haploid daughter cells are formed (gametes).

#### End Result of Meiosis: Four non-identical haploid cells, each with half the chromosome number of the original cell. In humans, this results in sperm or egg cells, each with 23 chromosomes.

#### Chromosome Number:

- Body Cells: Have a diploid number of chromosomes (2n), meaning they contain two sets of chromosomes. In humans, this is 46 chromosomes (23 pairs).

- Gametes (Sperm and Egg): Have a haploid number of chromosomes (n), meaning they contain only one set of chromosomes. In humans, gametes contain 23 chromosomes.

Genetics:

- Allele: An alternative form of a gene that can produce variations in traits (e.g., dominant or recessive alleles).

- Genotype: The genetic makeup of an organism (e.g., homozygous dominant: AA, heterozygous: Aa, homozygous recessive: aa).

- Phenotype: The observable physical expression of an organism's genotype (e.g., tall or short plants).

- Punnett Squares: A tool used to predict genetic outcomes based on allele combinations.

  - Monohybrid Cross: A cross that examines the inheritance of a single trait (e.g., Aa × Aa).

  - Dihybrid Cross: A cross that examines the inheritance of two traits (e.g., AaBb × AaBb).

#### Types of Genetic Inheritance:

- Complete Dominance: One allele completely masks the effect of the other. Example: In pea plants, T (tall) is dominant over t (short), so a plant with Tt will be tall.

- Incomplete Dominance: Neither allele is fully dominant, resulting in a blend of traits. Example: Red flowers (**RR**) × White flowers (**WW**) produce pink flowers (**RW**).

- Codominance: Both alleles are expressed equally. Example: In blood types, AB individuals express both A and B antigens.

#### Sex-Linked Traits:

- Traits that are carried on the X chromosome (or the Y chromosome, but this is rarer).

  - Example: Color blindness is an X-linked recessive trait. Since males have only one X chromosome, they are more likely to express the trait if they inherit the recessive allele. Females, with two X chromosomes, need two copies of the recessive allele to express the trait.

#### Pedigree:

- A pedigree is a diagram that tracks the inheritance of a trait through several generations.

  - Males are represented by squares, and females by circles.

  - Shaded symbols represent individuals who express the trait.

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### DNA: Chapter 13

#### Contributions to the Discovery of DNA:

- Hershey & Chase: Conducted experiments with bacteriophages (viruses that infect bacteria) to show that DNA, not protein, carries genetic information.

- Oswald Avery: Identified DNA as the molecule responsible for genetic transformation in bacteria.

- Watson & Crick: Proposed the double helix model of DNA, based on X-ray diffraction images taken by Rosalind Franklin.

- Rosalind Franklin: Used X-ray crystallography to capture images of DNA, which helped Watson and Crick determine its helical structure.

#### Structure of DNA:

- Nitrogenous Bases: DNA is made up of four nitrogenous bases:

  - Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).

  - Base Pairing:

    - Adenine (A) pairs with Thymine (T).

    - Cytosine (C) pairs with Guanine (G).

  - Chargaff’s Rule: The amount of adenine equals the amount of thymine, and the amount of cytosine equals the amount of guanine.

- DNA Backbone: Composed of phosphate groups and deoxyribose sugars. The phosphate and sugar molecules form the sides of the DNA ladder, while the nitrogenous bases form the rungs.

- Double Helix: DNA consists of two strands that twist around each other to form a double helix structure, which is stable and allows for easy replication.

#### Types of Bonds in DNA:

- Covalent Bonds: These bonds hold the phosphate and sugar molecules together in the DNA backbone.

- Hydrogen Bonds: Weak bonds that connect the nitrogenous bases between the two strands of DNA. These bonds allow the DNA to "unzip" for replication and transcription.

#### DNA Replication:

- Helicase: The enzyme that unwinds and separates the two strands of DNA.

- DNA Polymerase: The enzyme that adds complementary nucleotides to each original strand to form new DNA strands. It also proofreads to ensure accuracy.

#### Base Pairing:

- If you’re given a sequence of bases on one strand of DNA, you can determine the complementary strand using base pairing rules.

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