AP Biology: Key Terms

All cards in AP Biology: Key Terms

• Covalent bond

  (Chemistry) A bond formed when two atoms share electrons.

• Hydrogen bond

  (Chemistry) A weak attraction between a hydrogen atom and an electronegative atom.

• pH

  (Chemistry) A measure of hydrogen ion concentration; the acidity or basicity of a solution.

• Carbohydrate

  (Macromolecules) An organic molecule of sugars used for energy and structure.

• Protein

  (Macromolecules) A polymer of amino acids that carries out most cellular functions.

• Enzyme

  (Macromolecules) A protein that speeds up a reaction by lowering its activation energy.

• Lipid

  (Macromolecules) A hydrophobic molecule such as fats and phospholipids.

• Nucleic acid

  (Macromolecules) A polymer (DNA or RNA) that stores genetic information.

• Prokaryote

  (Cells) A cell lacking a nucleus and membrane-bound organelles.

• Eukaryote

  (Cells) A cell with a nucleus and membrane-bound organelles.

• Mitochondrion

  (Cells) The organelle that produces ATP through cellular respiration.

• Chloroplast

  (Cells) The organelle where photosynthesis occurs in plant cells.

• Cell membrane

  (Cells) The phospholipid bilayer that controls what enters and exits a cell.

• Diffusion

  (Transport) The movement of molecules from high to low concentration.

• Osmosis

  (Transport) The diffusion of water across a selectively permeable membrane.

• Active transport

  (Transport) Movement of molecules against their gradient using energy (ATP).

• ATP

  (Energy) The molecule that stores and supplies energy for cellular work.

• Cellular respiration

  (Energy) The process of breaking down glucose to produce ATP.

• Photosynthesis

  (Energy) The process by which plants convert light energy into glucose.

• Glycolysis

  (Energy) The breakdown of glucose into pyruvate in the cytoplasm.

• Mitosis

  (Cell division) Division producing two genetically identical diploid cells.

• Meiosis

  (Cell division) Division producing four genetically varied haploid gametes.

• DNA

  (Genetics) The double-helix molecule that carries genetic instructions.

• Replication

  (Genetics) The copying of DNA before cell division.

• Transcription

  (Genetics) The synthesis of RNA from a DNA template.

• Translation

  (Genetics) The synthesis of a protein from mRNA at the ribosome.

• Gene

  (Genetics) A segment of DNA that codes for a protein or trait.

• Allele

  (Genetics) An alternative form of a gene.

• Genotype

  (Genetics) The genetic makeup of an organism.

• Phenotype

  (Genetics) The observable physical traits of an organism.

• Dominant allele

  (Genetics) An allele expressed when at least one copy is present.

• Recessive allele

  (Genetics) An allele expressed only when two copies are present.

• Mutation

  (Genetics) A change in the DNA sequence.

• Natural selection

  (Evolution) The process by which favorable traits become more common over generations.

• Adaptation

  (Evolution) An inherited trait that improves survival and reproduction.

• Speciation

  (Evolution) The formation of a new species.

• Hardy-Weinberg equilibrium

  (Evolution) A state in which allele frequencies stay constant without evolutionary forces.

• Homeostasis

  (Systems) The maintenance of a stable internal environment.

• Negative feedback

  (Systems) A response that counteracts a change to restore balance.

• Ecosystem

  (Ecology) A community of organisms together with their physical environment.

• Producer

  (Ecology) An organism that makes its own food, usually via photosynthesis.

• Food web

  (Ecology) The interconnected feeding relationships in an ecosystem.

• Carrying capacity

  (Ecology) The maximum population size an environment can sustain.

• Biodiversity

  (Ecology) The variety of life in an ecosystem or on Earth.

• Carbon cycle

  (Ecology) The movement of carbon through organisms, the atmosphere, and the earth.