Pre-AP Biology 2025 Final Exam Review Flashcards

Exam Breakdown

3.1: Chemistry of Life

1. Macromolecules (3-1 Notes)

   • a. Identify the four macromolecules:

     • i. Describe their basic structure, monomers, and functions.

     • Carbohydrates: Composed of monosaccharides, provide energy and structural support.

     • Lipids: Composed of glycerol and fatty acids, store energy, form cell membranes, and act as hormones.

     • Proteins: Composed of amino acids, perform a wide variety of functions including enzymatic catalysis, transport, and structural support.

     • Nucleic Acids: Composed of nucleotides, store and transmit genetic information.

2. Enzymes (3-2 Notes)

   • a. Identify the function of enzymes.

     • Enzymes act as biological catalysts to speed up chemical reactions.

   • b. Describe how enzymes function:

     • i. Substrate, active site, product.

     • Substrate: The molecule upon which an enzyme acts.

     • Active Site: The region of an enzyme where the substrate binds and the reaction occurs.

     • Product: The result of the enzymatic reaction.

3. Energy of Life (3-3 Notes)

   • a. Describe the function of ATP.

     • ATP (Adenosine Triphosphate) is the primary energy currency of the cell, providing energy for various cellular processes.

   • b. Describe how ATP holds energy - ADP to ATP.

     • ATP stores energy in the phosphate bonds. When ATP is hydrolyzed to ADP (Adenosine Diphosphate) and a phosphate group, energy is released.

     • The energy is used for cellular activities, and ADP can be converted back to ATP through cellular respiration or photosynthesis.

3.2: Cellular Energy

1. Photosynthesis (3-4 Notes)

   • a. Describe the difference between autotrophs and heterotrophs.

     • Autotrophs: Organisms that produce their own food using light or chemical energy (e.g., plants, algae, cyanobacteria).

     • Heterotrophs: Organisms that obtain energy by consuming other organisms (e.g., animals, fungi).

   • b. Identify the equation for photosynthesis:

     • 6CO2 + 6H2O + Light Energy \rightarrow C6H{12}O6 + 6O2

   • c. Identify the two reactions in photosynthesis:

     • Light-dependent reactions

     • Light-independent reactions (Calvin Cycle)

   • d. Describe the light-dependent reactions of photosynthesis:

     • i. Purpose: Convert light energy into chemical energy (ATP and NADPH).

     • Occur in the thylakoid membranes of chloroplasts.

     • Involve the absorption of light by chlorophyll and other pigments.

     • Water is split, releasing oxygen, protons, and electrons.

     • ATP and NADPH are produced through electron transport and chemiosmosis.

   • e. Describe the light-independent reactions of photosynthesis:

     • i. Purpose: Use ATP and NADPH to convert CO_2 into glucose.

     • Occur in the stroma of chloroplasts.

     • Involve the Calvin Cycle, a series of reactions that fix CO_2, reduce it using ATP and NADPH, and regenerate the starting molecule.

     • Glucose is produced as the final product.

2. Cellular Respiration (3-5 Notes)

   • a. Identify the equation for cellular respiration:

     • C6H{12}O6 + 6O2 \rightarrow 6CO2 + 6H2O + Energy (ATP)

   • b. Identify the three steps in cellular respiration:

     • Glycolysis

     • Krebs Cycle (Citric Acid Cycle)

     • Electron Transport Chain (ETC)

   • f. Describe glycolysis:

     • i. Purpose: Break down glucose into pyruvate, producing a small amount of ATP and NADH.

     • Occurs in the cytoplasm.

     • Glucose is broken down into two molecules of pyruvate.

     • Produces 2 ATP molecules and 2 NADH molecules.

   • g. Describe the Krebs cycle:

     • i. Purpose: Further oxidize pyruvate, producing CO_2, ATP, NADH, and FADH2.

     • Occurs in the mitochondrial matrix.

     • Pyruvate is converted to acetyl-CoA, which enters the cycle.

     • Produces 2 ATP molecules, 6 NADH molecules, and 2 FADH2 molecules per glucose molecule.

   • h. Describe the electron transport chain:

     • i. Purpose: Use NADH and FADH2 to generate a large amount of ATP through oxidative phosphorylation.

     • Occurs in the inner mitochondrial membrane.

     • Electrons from NADH and FADH2 are passed along a series of protein complexes.

     • Energy is used to pump protons across the membrane, creating a gradient.

     • ATP synthase uses the proton gradient to produce ATP (oxidative phosphorylation).

     • Produces approximately 32 ATP molecules per glucose molecule.

3.3: Cell Growth, Division, and Homeostasis

1. Cell Structure (3-6 Notes)

   • a. Compare and contrast eukaryotes and prokaryotes.

     • Eukaryotes: Have a nucleus and other membrane-bound organelles (e.g., animals, plants, fungi, protists).

     • Prokaryotes: Do not have a nucleus or membrane-bound organelles (e.g., bacteria, archaea).

   • b. Identify and describe the functions of cell organelles.

     • Nucleus: Contains DNA and controls cell activities.

     • Mitochondria: Generates ATP through cellular respiration.

     • Ribosomes: Synthesizes proteins.

     • Endoplasmic Reticulum: Involved in protein and lipid synthesis.

     • Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.

     • Lysosomes: Digests cellular waste and debris.

     • Vacuoles: Stores water, nutrients, and waste.

     • Chloroplasts (in plant cells): Conducts photosynthesis.

     • Cell Wall (in plant cells): Provides structural support and protection.

2. Homeostasis (3-7 Notes)

   • a. Identify levels of organization in a multi-celled organism:

     • Cell → Tissue → Organ → Organ System → Organism

   • b. Describe negative and positive feedback:

     • i. Identify examples of negative feedback:

     • Body temperature regulation: If body temperature rises, the body sweats to cool down; if it drops, the body shivers to generate heat.

     • Blood glucose regulation: Insulin lowers blood glucose levels when they are high; glucagon raises blood glucose levels when they are low.

     • ii. Identify examples of positive feedback:

     • Blood clotting: Platelets activate more platelets to form a clot.

     • Childbirth: Uterine contractions stimulate the release of oxytocin, which further stimulates contractions.

   • c. Identify the stages of a negative feedback loop:

     • i. Stimulus, receptor, control center, effector, response.

     • Stimulus: A change in the internal environment.

     • Receptor: Detects the change.

     • Control Center: Processes the information and determines the appropriate response.

     • Effector: Carries out the response.

     • Response: Returns the internal environment to the normal range.

Unit 4: Genetics

4.1: Structure and Synthesis of DNA

1. Discovering DNA (4-1 Notes)

   • a. Describe DNA.

     • DNA (Deoxyribonucleic Acid) is the molecule that carries genetic information.

   • b. Describe the work of the scientists that contributed to the discovery of DNA:

     • i. Griffith: Discovered transformation in bacteria.

     • ii. Hershey and Chase: Proved that DNA is the genetic material.

     • iii. Chargaff: Discovered that the amount of adenine (A) equals the amount of thymine (T), and the amount of guanine (G) equals the amount of cytosine (C).

     • iv. Franklin: Used X-ray diffraction to reveal the helical structure of DNA.

     • v. Watson and Crick: Developed the double helix model of DNA.

     • vi. Messelson and Stahl: Demonstrated that DNA replication is semi-conservative.

2. The Structure and Function of DNA (4-2 Notes)

   • a. Identify the structural components of DNA:

     • Deoxyribose sugar, phosphate group, nitrogenous base (A, T, C, G).

     • i. What is the role of DNA?

     • Store genetic information.

     • ii. How does DNA replicate? Where does DNA replication take place?

     • DNA replication is semi-conservative and takes place in the nucleus.

     • Enzymes involved include DNA polymerase, helicase, and ligase.

     • iii. Why is DNA an important molecule?

     • It carries the instructions for building and operating a cell.

4.2: Protein Synthesis

1. Protein Synthesis (4-3 Notes)

   • a. Describe the overall goal of protein synthesis.

     • To create proteins from DNA instructions.

     • Involves transcription and translation.

     • i. Describe translation, including the enzymes involved. Where does translation take place?

     • Translation is the process of converting mRNA into a protein. It takes place in the ribosome.

     • Enzymes involved include aminoacyl-tRNA synthetases, peptidyl transferase, and release factors.

     1. Initiation

     2. Elongation

     3. Termination

2. Mutations (4-4 Notes)

   • a. Identify the different types of mutations.

     • i. Identify the types of gene mutations:

     1. What is a point mutation?

     • A single base change in DNA.

     • Includes substitutions, insertions, and deletions.

     1. What is a frameshift mutation?

     • An insertion or deletion of bases that shifts the reading frame.

     • a. Insertion

     • b. Deletion

   • b. What are the possible effects of mutations?

     • Silent: No change in the amino acid sequence.

     • Missense: Results in a different amino acid.

     • Nonsense: Results in a premature stop codon.

     • Frameshift: Alters the reading frame, leading to a completely different amino acid sequence.

4.3: Passing of Traits and Inheritance Patterns

1. Reproductive Strategies (4-5 Notes)

   • a. Describe the two types of reproductive strategies:

     • i. Describe asexual reproduction - what type of organisms reproduce asexually?

     • Asexual reproduction involves one parent and produces genetically identical offspring.

     • Bacteria, archaea, and some eukaryotes reproduce asexually

     1. Describe binary fission

     • Cell division in prokaryotes.

     1. Describe budding

     • A new organism grows from an outgrowth or bud on the parent.

     1. Describe fragmentation

     • A parent organism breaks into fragments, each capable of growing independently into a new organism.

       • ii. Describe sexual reproduction - what type of organisms reproduce sexually?

       • Sexual reproduction involves two parents and produces genetically diverse offspring.

       • Most eukaryotes reproduce sexually.

     1. What is a gamete?

     • A haploid sex cell (sperm or egg).

2. Meiosis (4-6 Notes)

   • a. What is meiosis?

     • A type of cell division that reduces the chromosome number by half, producing haploid gametes.

   • b. Identify the difference between sister chromatids and homologous chromosomes.

     • Sister chromatids are identical copies of a single chromosome.

     • Homologous chromosomes are chromosome pairs (one from each parent) that are similar but not identical.

   • c. Describe meiosis I, including the different phases.

     • Prophase I: Chromosomes condense, homologous chromosomes pair up, crossing over occurs.

     • Metaphase I: Homologous chromosome pairs align at the metaphase plate.

     • Anaphase I: Homologous chromosomes separate and move to opposite poles.

     • Telophase I: Chromosomes arrive at the poles, and the cell divides.

   • d. Describe meiosis II, including the different phases.

     • Prophase II: Chromosomes condense.

     • Metaphase II: Chromosomes align at the metaphase plate.

     • Anaphase II: Sister chromatids separate and move to opposite poles.

     • Telophase II: Chromosomes arrive at the poles, and the cell divides.

   • e. What is the end goal of meiosis?

     • To produce four haploid gametes from one diploid cell.

   • f. Identify the types of chromosomal mutations:

     • i. Deletion

     • ii. Duplication

     • iii. Inversion

     • iv. Translocation

3. Mendelian Inheritance (4-7 Notes)

   • a. Why is Gregor Mendel an important scientist?

     • He is considered the father of genetics for his work on pea plants.

   • b. Describe Mendel’s three conclusions:

     • i. Theory of Particulate Inheritance

     • ii. The Principle of Dominance

     • iii. The Principle of Independent Assortment

   • c. What is a gene?

     • A unit of heredity that is transferred from a parent to offspring and determines a characteristic.

   • d. What is a genotype?

     • The genetic makeup of an organism.

   • e. What is a phenotype?

     • The observable characteristics of an organism.

   • f. What is the difference between homozygous and heterozygous?

     • Homozygous: having two identical alleles for a gene.

     • Heterozygous: having two different alleles for a gene.

     • i. Identify the three genotypes in Mendelian inheritance:

     • Homozygous dominant (e.g., AA), homozygous recessive (e.g., aa), heterozygous (e.g., Aa).

     • ii. Be able to complete a Punnett Square.

4. Beyond Mendelian Inheritance (4-8 Notes)

   • a. Describe incomplete dominance.

     • A condition in which neither allele is dominant, and the heterozygote phenotype is intermediate between the two homozygous phenotypes.

   • b. Describe codominance.

     • A condition in which both alleles are equally expressed in the heterozygote phenotype.

4.4: Cell Membrane Structure

1. Cell Membrane Structure (4-9 Notes)

   • a. Describe the structure of the cell membrane.

     • i. Describe the lipid bilayer and Fluid Mosaic model.

     • The cell membrane is composed of a phospholipid bilayer with embedded proteins.

     • The fluid mosaic model describes the flexible nature of the membrane components.

   • b. Describe the function of the cell membrane.

     • Controls what enters and exits the cell.

     • Maintains cell integrity and communication.

2. Passive Cell Transport (4-10 Notes)

   • a. Describe diffusion and how it works.

     • i. Passive and facilitated diffusion.

     • Diffusion moves substances from an area of high concentration to an area of low concentration.

     • Facilitated diffusion uses transport proteins to help substances cross the membrane.

   • b. Describe osmosis and how it works.

     • i. Tonicity - hypertonic, hypotonic, isotonic.

     • Osmosis is the movement of water across a semipermeable membrane from an area of high water concentration to an area of low water concentration.

     • Tonicity refers to the relative concentration of solutes in the solution compared to the cell (hypertonic - more solutes, hypotonic - less solutes, isotonic - equal solutes).

3. Active Cell Transport (4-11 Notes)

   • a. Describe molecular transport and how it works.

     • Active transport requires energy (ATP) to move substances against their concentration gradient.

   • b. Describe bulk transport and how it works.

     • i. Endocytosis and exocytosis.

     • Endocytosis is the process of bringing substances into the cell by engulfing them in a vesicle.

     • Exocytosis is the process of releasing substances from the cell by fusing a vesicle with the cell membrane.