AP Biology Exam Review

Vocabulary flashcards for key concepts in biochemistry, cells, energy, molecular genetics, regulation, evolution, and ecology.

Ionic Bond

Bond where electrons are transferred.

Covalent Bond

Bond where electrons are shared. Can be polar (unequal sharing) or non-polar (equal sharing).

Hydrogen Bond

Weak bond between hydrogen and negatively charged items.

Hydrophobic Interactions

How non-polar compounds congregate together, characteristic of lipids.

Acid

A substance with a pH less than 7, indicating a higher concentration of H+ ions.

Base

A substance with a pH greater than 7, indicating a lower concentration of H+ ions.

Cohesion

Attraction between water molecules.

Adhesion

Attraction of water molecules to other charged compounds.

Dehydration Synthesis

Process by which monomers join together to form polymers with the loss of water.

Hydrolysis

Process by which polymers are broken down into monomers with the input of water.

Monosaccharide

Monomer of carbohydrates, such as glucose.

Disaccharide

Two monosaccharides joined together.

Polysaccharide

Three or more monosaccharides joined together, such as starch, glycogen, or cellulose.

Saturated Fat

Lipid with single bonds between carbons.

Unsaturated Fat

Lipid with at least one double bond between carbons.

Phospholipid

Lipid that makes up cell membranes and is amphipathic (hydrophilic and hydrophobic).

Amino Acid

Monomer of proteins, containing a carboxyl group, amino group, central carbon, and variable R group.

Primary Structure

The sequence of amino acids in a protein.

Secondary Structure

The structure where hydrogen bonds form beta pleated sheets or alpha helices in a protein.

Tertiary Structure

The globular structure of a protein formed from disulfide bridges, hydrogen bonds, hydrophobic interactions and ionic bonding.

Quaternary Structure

The structure of a protein with more than one polypeptide chain.

Nucleotide

Monomer of nucleic acids, made up of a sugar, phosphate, and base.

DNA

Double stranded nucleic acid that stores genetic information, contains deoxyribose, and uses the bases A, G, C, and T.

RNA

Single stranded nucleic acid that plays a role in protein synthesis, contains ribose, and uses the bases A, G, C, and U.

Enzyme

Biological catalyst (made of protein) that speeds up rate of chemical reactions by lowering activation energy.

Active Site

The location on an enzyme where the substrate binds and the reaction occurs (exposed R groups).

Catabolic Reaction

Reaction in which enzymes break down a substance.

Anabolic Reaction

Reaction in which enzymes build up substances.

Substrate

The substance on which an enzyme acts.

Competitive Inhibition

Inhibition where something competes for the active site, can be overcome with more substrate.

Non-Competitive Inhibition

Inhibition where something attaches at the allosteric site and changes the shape of enzyme so it is not functional, can not be overcome with more substrate.

Coenzyme

Organic molecule that interacts with enzymes to put them into the right structure to do work (NAD and Vitamin B).

Cofactor

Inorganic molecule that interacts with enzymes to put them into the right structure to do work (Zinc, Magnesium).

Prokaryotic Cell

Cell lacking membrane-bound organelles and a nucleus.

Eukaryotic Cell

Cell containing membrane-bound organelles and a nucleus.

Nucleus

Organelle that holds DNA and the nucleolus where ribosomal subunits are made.

Mitochondria

Organelle with a double membrane where ATP is made during cellular respiration.

Ribosome

Organelle that translates RNA into protein.

Endoplasmic Reticulum

Membranous organelle connected to the nucleus, smooth synthesizes lipids, rough synthesizes proteins.

Golgi Complex

Organelle that packages molecules in membranes and signals for export.

Lysosome

Animal cell organelle that contains enzymes used for intracellular digestion and apoptosis.

Chloroplast

Plant cell organelle with a double membrane where photosynthesis (glucose synthesis) occurs.

Cell Wall

Plant cell organelle composed of a middle lamella, primary cell wall, and secondary cell wall.

Endosymbiont Theory

Theory that all eukaryotic cells came from bacterial cells that lived together.

Cell Membrane

Separates the internal environment of the cell from the external environment. Composed of a phospholipid bilayer (selectively permeable; amphipathic).

Simple Diffusion

From high to low concentration- small and uncharged move freely through phospholipids (passive transport).

Facilitated Diffusion

Large or charged molecules move from high to low concentration with a protein carrier (passive transport).

Active Transport

Molecules move from low to high concentration, requires ATP, and a protein.

Endocytosis

Phagocytosis (solid) and pinocytosis (liquid) process where the membrane surrounds and forms vesicles.

Exocytosis

Releasing of material using vesicles fusing with membrane.

Osmosis

Diffusion of water using a selectively permeable membrane (passive transport).

Hypertonic

Solution with high solute concentration.

Hypotonic

Solution with low solute concentration.

Isotonic

Solution with equal solute concentration.

Neuron

A nerve cell; the basic building block of the nervous system.

Neurotransmitter

A chemical messenger that carries signals between neurons.

Depolarization

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.

Repolarization

The process during the action potential when sodium and potassium are exchanged through the sodium-potassium pump.

1st Law of Thermodynamics

Matter and energy are not created but change form.

Cellular Respiration

Process that makes ATP for cell use; uses glucose and oxygen and makes waste products of carbon dioxide and water; occurs in mitochondria; NADH is used as an electron carrier.

Glycolysis

Occurs in cytoplasm; rearranges the bonds in glucose molecules, releasing free energy to form ATP from ADP anaerobic process.

Krebs Cycle

Occurs in mitochondrial matrix; pyruvate is oxidized further and carbon dioxide is released ; ATP is synthesized from ADP and inorganic phosphate via substrate level phosphorylation and electrons are captured by coenzymes (NAD+ and FAD).

Electron Transport Chain

The electron transport chain captures electrons, pumping H+ ions into the inter-membrane space of the mitochondria.

Photosynthesis

Photosynthetic organisms capture free energy present in sunlight and use water and carbon dioxide to make carbon products and free oxygen.

Light-Dependent Reactions

Photosystems I and II (chlorophyll and proteins) are embedded in the internal membranes of chloroplasts. They pass electrons through an electron transport chain (ETC).

Light-Independent Reactions

Carbon fixation occurs (carbons of CO2 used to make sugar); occurs in stroma of chloroplasts; ATP and NADPH generated by light-dependent reactions are used to assemble glucose.

Anaerobic Fermentation

No oxygen; cell only goes through glycolysis followed by fermentation.

Mitosis

Cell division occurring after interphase, resulting two identical cells or clones.

Meiosis

Occurs after interphase, takes diploid cells and reduces the chromosome number to haploid.

Law of Dominance

One allele will be expressed over another.

Law of Segregation

Alleles pairs separate from each other during meiosis.

Law of Independent Assortment

Alleles assort independently during meiosis IF they are on separate chromosomes.

Incomplete Dominance

red X white  pink; both protein product are expressed and blended.

Codominance

red x white  red and white; both protein products are equally expressed ex.AB blood types.

Epistasis

One gene affects expression of another.

Linked Genes

Genes on same chromosome that are inherited together (can be unlinked by crossing over); recombination frequency calculated by recombinants/total; used for chromosome mapping.

Polygenic

Continuous variation, many genes affect one trait- height, color.

Autosomes

22 pairs of chromosomes in human genome.

Sex Chromosomes

1 pair of chromosomes in human genome.

Nondisjunction

Failure of chromosomes to separate at anaphase of meiosis.

Mutation

Any change of DNA sequence, can be inheritable if it is in egg or sperm.

DNA

Deoxyribose nucleic acid, double helix, antiparallel strands made of nucleotides each with a phosphate + 5C deoxyribose sugar + nitrogen base.

DNA Replication

Process of making exact copies of DNA semi conservatively (original strand is copied).

Transcription

Making mRNA in nucleus, enzyme RNA pol reads the DNA in 3’ to 5’ direction and synthesizes complementary mRNA.

Translation

mRNA code is read and matched with tRNA (brings amino acids) to construct a polypeptide using the ribosome.

Negative Feedback

Mechanisms that maintain dynamic homeostasis for a particular condition (variable) by regulating physiological processes, returning the changing condition back to its target set point.

Positive Feedback

Mechanisms that amplify responses and processes in biological organisms, initiating an additional response that produces system change.

Signal Transduction

The process by which a signal is converted to a cellular response.

Natural Selection

Major mechanism of change over time – Darwin’s theory of evolution.

Adaptation

A genetic variation that is favored by selection and is manifested as a trait that provides an advantage to an organism in a particular environment.

Fitness

The ability to survive and reproduce.

Hardy-Weinberg Equilibrium

A mathematical model used to calculate changes in allele frequency, providing evidence for the occurrence of evolution in a population.

Speciation

An evolutionary process by which 2 or more species arise from 1 species and 2 new species can no longer breed and reproduce successfully.

Habitat

Type of area an organism lives.

Niche

Role of an organism in ecosystem.

Exponential Growth

J-shaped, unlimited growth.

Logistic Growth

S-shaped, limited growth.

Carrying Capacity

Maximum population supported by habitat.

Symbiosis

Species interaction.

Mutualism

+/+ interaction.