AP Bio Final Exam
Macromolecules
1. Carbohydrates
Monomer: Monosaccharides (e.g., glucose, fructose).
Polymer: Polysaccharides (e.g., starch, glycogen, cellulose).
Key Processes:
Glycogenesis: Formation of glycogen (energy storage in liver and muscles) from glucose.
Location: Cytoplasm of liver and muscle cells.
Glycogenolysis: Breakdown of glycogen to glucose for energy.
Location: Liver and muscle cells.
Cell Wall Formation: Cellulose forms the rigid structure of plant cell walls.
Location: Plant cell walls.
2. Lipids
Monomer: Fatty acids and glycerol.
Polymer: Triglycerides, phospholipids, steroids.
Key Processes:
Fatty Acid Synthesis: Formation of fatty acids from acetyl-CoA for triglyceride production.
Location: Cytoplasm (especially liver and adipose cells).
Beta-oxidation: Breakdown of fatty acids to acetyl-CoA for energy production.
Location: Mitochondria (especially in muscle cells).
Phospholipid Synthesis: Formation of phospholipids for cell membrane structure.
Location: Smooth Endoplasmic Reticulum (ER) and Golgi apparatus.
Cholesterol Synthesis: Production of cholesterol for membrane stability and steroid hormone synthesis.
Location: Liver (in the cytoplasm and smooth ER).
3. Proteins
Monomer: Amino acids.
Polymer: Polypeptides.
Key Processes:
Protein Synthesis (Translation):
Location: Ribosomes (free in the cytoplasm or on the rough ER).
Process: mRNA is translated into a polypeptide chain.
Protein Folding: After translation, polypeptides fold into their functional 3D structures.
Location: Endoplasmic Reticulum (ER) (rough ER) and Golgi Apparatus.
Post-translational Modifications: Modifications like phosphorylation, glycosylation, and cleavage that activate or modify proteins.
Location: Golgi apparatus, cytoplasm, and nucleus.
4. Nucleic Acids
Monomer: Nucleotides.
Polymer: DNA and RNA.
Key Processes:
DNA Replication: DNA is copied prior to cell division.
Location: Nucleus (in eukaryotic cells).
Transcription: Synthesis of mRNA from a DNA template.
Location: Nucleus.
RNA Processing: mRNA is modified before leaving the nucleus.
Location: Nucleus (includes splicing, 5' cap addition, and poly-A tail).
Translation: mRNA is translated into a protein at ribosomes.
Location: Cytoplasm (ribosomes).
ATP Hydrolysis: ATP is broken down to ADP and phosphate to release energy.
Location: Cytoplasm and mitochondria.
Cell Structure and Function
Key Organelles and Processes
Nucleus: Stores genetic material (DNA); site of transcription.
Process: Transcription of DNA into RNA.
Location: Nucleus.
Ribosomes: Sites of protein synthesis.
Process: Translation of mRNA into polypeptides.
Location: Free in cytoplasm or attached to the rough ER.
Endoplasmic Reticulum (ER):
Rough ER: Protein synthesis (membrane-bound and secreted proteins).
Process: Protein synthesis.
Location: Rough ER.
Smooth ER: Lipid synthesis, detoxification.
Process: Lipid synthesis, detoxification.
Location: Smooth ER.
Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.
Process: Post-translational modifications (e.g., glycosylation).
Location: Golgi Apparatus.
Mitochondria: Site of cellular respiration (ATP production).
Process: Cellular respiration (Glycolysis, Krebs Cycle, Electron Transport Chain).
Location: Mitochondria (Glycolysis in cytoplasm, Krebs and ETC in mitochondria).
Lysosomes: Contain digestive enzymes to break down waste materials.
Process: Autophagy (self-digestion), phagocytosis (digestion of engulfed material).
Location: Lysosomes.
Peroxisomes: Break down fatty acids and detoxify harmful substances.
Process: Beta-oxidation (fatty acid breakdown) and detoxification of hydrogen peroxide.
Location: Peroxisomes.
Plasma Membrane: Semi-permeable membrane that regulates entry and exit of materials.
Process: Active transport, facilitated diffusion, and endocytosis/exocytosis.
Location: Plasma Membrane.
Hereditary
DNA Replication
Process: DNA is copied during the S phase of the cell cycle.
Enzymes: DNA Helicase (unwinds the DNA), DNA Polymerase (synthesizes new strands), Ligase (joins Okazaki fragments on the lagging strand).
Location: Nucleus (in eukaryotes).
Transcription
Process: Synthesis of RNA (mRNA) from a DNA template.
Enzyme: RNA Polymerase.
Location: Nucleus.
Translation
Process: mRNA is translated into a polypeptide at ribosomes.
Location: Cytoplasm (at ribosomes).
Mendelian Genetics
Process: Involves the inheritance of traits based on dominant and recessive alleles.
Location: Nucleus (genes are inherited through DNA).
Cell Energetics
1. Cellular Respiration (Aerobic)
Process: Converts glucose into ATP through Glycolysis, Krebs Cycle, and Electron Transport Chain (ETC).
Location:
Glycolysis: Cytoplasm.
Krebs Cycle: Mitochondrial matrix.
ETC: Inner mitochondrial membrane.
2. Anaerobic Respiration (Fermentation)
Process: In the absence of oxygen, glucose is broken down into lactic acid (in animals) or ethanol (in yeast).
Location: Cytoplasm.
3. Photosynthesis
Process: Converts light energy into chemical energy (glucose) in plants.
Stages:
Light Reactions: Light energy is captured to produce ATP and NADPH.
Location: Thylakoid membranes in the chloroplasts.
Calvin Cycle: ATP and NADPH are used to convert CO₂ into glucose.
Location: Stroma of chloroplasts.
Cell Cycle and Communication
1. Cell Cycle
Phases:
Interphase:
G1: Cell growth.
S: DNA synthesis (replication).
G2: Preparation for mitosis.
Mitosis:
Prophase: Chromosomes condense, nuclear membrane breaks down.
Metaphase: Chromosomes align in the center.
Anaphase: Sister chromatids are pulled apart.
Telophase: Nuclear membrane reforms.
Cytokinesis: Division of the cytoplasm.
2. Cell Communication (Signal Transduction)
Process: Cells respond to signals (e.g., hormones, growth factors) through receptors and secondary messengers.
Key Steps:
Reception: Signal molecule (ligand) binds to a receptor on the cell membrane.
Location: Plasma Membrane (G-protein coupled receptors, receptor tyrosine kinases).
Transduction: Signal is relayed inside the cell, often involving secondary messengers like cAMP or calcium ions.
Location: Cytoplasm (involves protein kinases, G-proteins).
Response: Activation of target molecules that carry out the response (e.g., gene expression, enzyme activation).
Location: Nucleus (for gene regulation), Cytoplasm (for enzyme activation)
Macromolecules
1. Carbohydrates
Monomer: Monosaccharides (simple sugars like glucose, fructose, and galactose).
Polymer: Polysaccharides (long chains of monosaccharides).
Examples:
Starch: Energy storage in plants.
Glycogen: Energy storage in animals.
Cellulose: Structural component of plant cell walls.
Chitin: Structural component in exoskeletons of arthropods and fungi.
Functions:
Energy Storage: Starch and glycogen store energy.
Structural Support: Cellulose in plants and chitin in fungi and arthropods.
Cell Signaling: Carbohydrates attached to proteins/lipids (glycoproteins/glycolipids) aid in cell-cell recognition and communication.
2. Lipids
Monomer: Fatty acids and Glycerol.
Polymer: Triglycerides, Phospholipids, Steroids.
Examples:
Triglycerides (fats/oils): Energy storage.
Phospholipids: Main component of cell membranes.
Steroids: Cholesterol, hormones (e.g., estrogen, testosterone).
Functions:
Energy Storage: Efficient long-term energy storage (fats).
Membrane Structure: Phospholipid bilayers form the basic structure of cell membranes.
Signaling: Steroid hormones regulate biological processes.
Insulation: Lipids help insulate organs and maintain body temperature.
3. Proteins
Monomer: Amino acids (20 types).
Polymer: Polypeptides (chains of amino acids).
Examples:
Enzymes: Catalyze biochemical reactions (e.g., amylase, DNA polymerase).
Structural Proteins: Collagen (connective tissue), keratin (hair, skin).
Transport Proteins: Hemoglobin (carries oxygen).
Hormones: Insulin (regulates blood sugar levels).
Functions:
Catalysis: Enzymes speed up reactions.
Structural Support: Collagen and elastin provide structure to tissues.
Transport: Hemoglobin carries oxygen in red blood cells.
Movement: Actin and myosin in muscle contraction.
Immune Response: Antibodies recognize and neutralize foreign invaders.
4. Nucleic Acids
Monomer: Nucleotides (made of a sugar, phosphate group, and nitrogenous base).
Polymer: DNA and RNA.
Examples:
DNA: Stores genetic information (double-stranded).
RNA: Translates genetic information into proteins (single-stranded).
ATP: Provides energy for cellular activities.
Functions:
Genetic Information Storage: DNA carries the genetic blueprint.
Protein Synthesis: RNA acts as a template for protein production.
Energy Transfer: ATP carries energy for cellular processes.
Cell Structure and Function
1. Organelles and Their Functions
Nucleus: Stores genetic material (DNA), site of transcription (RNA synthesis).
Ribosomes: Synthesize proteins from mRNA (can be free in cytoplasm or attached to rough ER).
Endoplasmic Reticulum (ER):
Rough ER: Studded with ribosomes, synthesizes proteins and folds them.
Smooth ER: Synthesizes lipids, detoxifies drugs and poisons.
Golgi Apparatus: Modifies, packages, and sorts proteins and lipids for export or use inside the cell.
Mitochondria: Site of cellular respiration, produces ATP.
Chloroplasts: Site of photosynthesis (in plant cells).
Lysosomes: Contain digestive enzymes to break down waste and cellular debris.
Peroxisomes: Break down fatty acids and detoxify harmful substances.
Plasma Membrane: Regulates what enters and leaves the cell; involved in cell communication and transport (phospholipid bilayer).
2. Cytoskeleton
Microtubules: Provide structural support, shape, and track for motor proteins.
Microfilaments (actin filaments): Involved in cell movement, muscle contraction, and cell division.
Intermediate Filaments: Provide mechanical strength to the cell.
3. Cell Transport
Passive Transport: Movement of molecules without energy (down a concentration gradient).
Diffusion: Movement of small molecules (e.g., oxygen, CO₂).
Facilitated Diffusion: Movement of larger molecules (e.g., glucose) through membrane proteins.
Osmosis: Movement of water across a selectively permeable membrane.
Active Transport: Requires energy (ATP) to move molecules against a concentration gradient.
Sodium-Potassium Pump: Pumps Na⁺ out and K⁺ into cells.
Endocytosis/Exocytosis: Bulk transport of large molecules into (endocytosis) or out of (exocytosis) cells.
Hereditary
1. DNA Structure and Replication
Structure: Double helix made of nucleotides (adenine pairs with thymine, guanine pairs with cytosine).
Replication: Semi-conservative process where DNA strands separate and each serves as a template for a new strand.
Key Enzymes:
DNA Helicase: Unwinds the DNA double helix.
DNA Polymerase: Adds nucleotides to the growing strand.
Ligase: Joins Okazaki fragments on the lagging strand.
2. Gene Expression
Transcription: Synthesis of RNA from a DNA template.
RNA polymerase: Enzyme that synthesizes mRNA.
mRNA: Messenger RNA carries genetic information from the DNA in the nucleus to the ribosomes.
Translation: Synthesis of proteins from mRNA at ribosomes.
tRNA: Transfers amino acids to the ribosome.
Codons: Sets of three bases on mRNA that specify particular amino acids.
3. Mendelian Genetics
Alleles: Different forms of a gene (dominant or recessive).
Genotype: Genetic makeup (e.g., homozygous, heterozygous).
Phenotype: Physical expression of the genotype.
Punnett Squares: Tool for predicting the genetic outcomes of crosses.
Law of Segregation: Two alleles for a trait separate during gamete formation.
Law of Independent Assortment: Genes for different traits segregate independently of each other.
Cell Energetics
1. ATP (Adenosine Triphosphate)
Structure: Consists of adenine, ribose, and three phosphate groups.
Function: ATP is the primary energy carrier in cells, used for cellular work (e.g., active transport, muscle contraction).
2. Cellular Respiration
Location: Cytoplasm (Glycolysis), Mitochondria (Krebs Cycle, Electron Transport Chain).
Stages:
Glycolysis: Breaks down glucose into pyruvate, producing 2 ATP and 2 NADH.
Krebs Cycle: Converts pyruvate into carbon dioxide, producing NADH, FADH₂, and 2 ATP.
Electron Transport Chain (ETC): NADH and FADH₂ donate electrons to the chain, producing a proton gradient, which drives ATP synthesis (32-34 ATP).
Anaerobic Respiration (Fermentation):
In the absence of oxygen, glycolysis continues, but the pyruvate is converted into lactic acid (in animals) or ethanol (in yeast), producing a small amount of ATP.
3. Photosynthesis
Location: Chloroplasts (thylakoid membranes and stroma).
Stages:
Light Reactions: Occur in the thylakoid membranes, where light energy is used to produce ATP and NADPH.
Calvin Cycle: Occurs in the stroma, using ATP and NADPH to convert carbon dioxide into glucose.
Cell Cycle and Communication
1. Cell Cycle
Phases:
Interphase: G1 (growth), S (DNA synthesis), G2 (preparation for mitosis).
Mitosis: Division of the nucleus.
Prophase: Chromosomes condense, spindle fibers form.
Metaphase: Chromosomes align in the center.
Anaphase: Sister chromatids separate.
Telophase: Nuclear membrane reforms.
Cytokinesis: Division of the cytoplasm.
Regulation: Checkpoints (e.g., G1, G2, metaphase) ensure the cell cycle proceeds correctly.
2. Cell Communication
Signal Transduction Pathways: Signal molecules (ligands) bind to receptors on the cell surface, triggering a cascade of events inside the cell.
Receptors: G-protein coupled receptors, receptor tyrosine kinases.
Second Messengers: Molecules like cAMP or calcium ions that amplify the signal inside the cell.
Types of Signaling:
Autocrine: Cells signal themselves.
Paracrine: Cells signal nearby cells.
Endocrine: Hormones signal distant cells (e.g., insulin).
Juxtacrine: Direct signaling between adjacent cells through physical contact