AP Bio Semester Review

Hydrogen bonds

Attractions between polar molecules due to charge differences.

Cohesion

Water molecules attract each other, creating surface tension.

Adhesion

Water molecules cling to different molecules, aiding transport.

Capillary action

Water rises due to adhesive forces exceeding cohesive forces.

High specific heat

Water resists temperature changes, stabilizing environments.

Less dense as a solid

Ice floats, allowing aquatic life in winter.

Universal solvent

Water dissolves ionic and polar substances effectively.

Dehydration reaction

Removes water to form polymers from monomers.

Hydrolysis reaction

Adds water to break down polymers into monomers.

Carbohydrates

Organic compounds made of C, H, O; energy sources.

Lipids

Fats and oils, composed of C, H, O (P in phospholipids).

Proteins

Polymers of amino acids, containing C, H, O, N, (S).

Nucleic Acids

Polymers of nucleotides, containing C, H, O, N, P.

Saturated fatty acids

No double bonds, tightly packed fatty acid chains.

Unsaturated fatty acids

At least one double bond, creating kinks in chains.

Primary protein structure

Determined by the sequence of amino acids.

Secondary protein structure

Coils and folds from hydrogen bonding in polypeptide.

Tertiary protein structure

3D shape from interactions of amino acid side chains.

Quaternary protein structure

Association of multiple polypeptides into a functional complex.

Nucleotide components

Pentose sugar, phosphate group, nitrogen base.

DNA vs RNA

Both are nucleic acids; DNA is double-stranded, RNA is single.

A-T bonding

Adenine bonds to thymine with 2 hydrogen bonds.

C-G bonding

Cytosine bonds to guanine with 3 hydrogen bonds.

Prokaryotic cells

No nucleus, smaller, circular DNA, lack organelles.

Eukaryotic cells

Have a nucleus, larger, linear DNA, contain organelles.

Protein synthesis path

DNA -> mRNA -> ribosome -> amino acid chain -> protein.

Ribosome

Produces proteins within the cell.

Rough ER

Contains ribosomes; processes secreted proteins.

Smooth ER

Synthesizes lipids and detoxifies the cell.

Golgi

Modifies and packages proteins into vesicles.

Lysosome

Breaks down waste and old cell parts.

Vacuole

Storage container for food and water.

Mitochondria

Breaks down glucose to produce ATP.

Chloroplasts

Converts sunlight into glucose.

Folded Membrane

Increases surface area for energy reactions.

Surface Area to Volume Ratio

Decreases as a cell grows larger.

High Surface Area to Volume Ratio

Facilitates regulation of substances in cells.

Cell Adaptations

Includes folds and projections to increase ratio.

Spherical Cell Ratio

Surface area to volume ratio is 0.6.

Cuboidal Cell Ratio

Surface area to volume ratio is 0.86.

Phosphate Head

Part of a phospholipid molecule.

Fatty Acid Tails

Hydrophobic part of phospholipid.

Glycolipid

Lipid with carbohydrate attached.

Glycoprotein

Protein with carbohydrate attached.

Cholesterol

Regulates membrane fluidity at varying temperatures.

Passive Transport

Moves substances down concentration gradient without energy.

Active Transport

Uses ATP to move substances against gradient.

Facilitated Diffusion

Passive transport requiring a channel or carrier.

Hypertonic Solution

Higher solute concentration outside; cell shrinks.

Isotonic Solution

Equal water movement; cell size remains same.

Hypotonic Solution

Higher solute concentration inside; cell swells.

Endosymbiotic Theory

Eukaryotic cells engulfed prokaryotes, forming mutualism.

Endosymbiotic Evidence

Double membranes, own ribosomes, circular DNA.

Enzymes

Belong to the class of proteins.

Active site

Part of enzyme where substrate binds.

Substrate

Reactant that the enzyme acts on.

Allosteric site

Area for noncompetitive inhibitors to bind.

Activation energy

Energy needed to convert reactants to products.

Enzyme saturation

All enzymes full; max reaction rate reached.

Temperature effect on enzymes

Increases speed until denaturation occurs.

Competitive inhibition

Inhibitor blocks active site of enzyme.

Noncompetitive inhibition

Inhibitor binds allosteric site, altering active site.

Autotrophs

Producers that synthesize their own food.

Heterotrophs

Consumers that obtain food from others.

Light dependent reactions

Occur in thylakoid membrane of chloroplasts.

Calvin cycle

Light independent reactions in chloroplast stroma.

ATP and NADPH

Molecules produced in light dependent reactions.

Chlorophyll location

Found in photosystems of chloroplasts.

Water splitting

Replaces lost electrons in photosystems, releasing oxygen.

Hydrogen gradient

Created by H+ pumping, used for ATP synthesis.

Calvin cycle inputs

Uses ATP and NADPH to produce glucose.

Carbon dioxide

Gas entering plant for Calvin cycle.

Photorespiration

Occurs when oxygen binds instead of carbon dioxide.

Glycolysis

First stage of cellular respiration in cytoplasm.

Kreb's cycle

Occurs in mitochondria, produces ATP and NADH.

Electron transport chain

Final stage, produces 32-34 ATPs and water.

Oxygen's role

Final electron acceptor forming water in ETC.

Fermentation

Produces NAD+ for glycolysis in absence of oxygen.

Direct contact signaling

Communication through cell junctions like gap junctions.

Local signaling

Includes paracrine and synaptic signaling methods.

Endocrine signaling

Hormone release into the circulatory system.

Reception

Ligand binds to receptor in target cells.

Transduction

Extracellular signal converted to intracellular signal.

Response

Signal triggers changes in cellular processes.

Receptors outside cell

Located on plasma membrane for polar ligands.

Receptors inside cell

Found in cytoplasm for hydrophobic ligands.

Second messengers

Small molecules that relay and amplify signals.

Cyclic AMP (cAMP)

Common second messenger in cell signaling.

Protein kinases

Enzymes that phosphorylate and relay signals.

Protein phosphatases

Enzymes that dephosphorylate and shut off pathways.

Cell response types

Alter membrane permeability, metabolic processes, gene expression.

Gene turned on

Production of a protein occurs.

Gene turned off

Production of a protein ceases.

Negative feedback

Reduces stimulus effect; e.g., body temperature regulation.

Positive feedback

Increases stimulus effect; e.g., childbirth process.

Sister chromatids

Identical copies of a chromosome connected at centromere.

Kinetochore

Protein structure on chromatids for spindle attachment.

Spindle

Microtubule structure that separates chromosomes.

Centromere

Region where sister chromatids are joined.

Human chromosomes

46 total; 23 from each parent.