AP Biology Exam Review Vocabulary

This JSON file contains vocabulary flashcards related to AP Biology exam review. The flashcards cover key concepts and definitions from various units, including the chemistry of life, cell structure and function, cellular energetics, heredity, gene expression and regulation, natural selection, and ecology.

Electronegativity

The measure of the tendency of an atom to attract a bonding pair of electrons.

Polar Molecule

A molecule with an asymmetrical distribution of charge.

Cohesion

Water molecules stick together, creating surface tension and allowing water to form droplets.

Adhesion

Water molecules adhere to other substances, enabling capillary action and facilitating the movement of water in plants.

Transpiration

Water vapor is released from plants through small pores, contributing to the water cycle.

High-Specific Heat

Water can absorb and retain a large amount of heat, helping to moderate temperatures on Earth.

Surface tension

Arises from the cohesive forces between water molecules at the surface.

Dehydration synthesis

Subcomponents of a water molecule (H and OH) are removed from interacting monomers, forming a covalent bond between them.

Hydrolysis

Involve the cleavage of covalent bonds between amino acids; a water molecule is hydrolyzed, and its subcomponents (H and OH) are bonded to different amino acids, resulting in the separation of amino acid monomers.

Genome

The complete set of genes or genetic material present in a cell or organism.

Ribosomes

Responsible for protein synthesis based on mRNA sequences, which are derived from the cell's genome. Composed of two subunits and are not enclosed by membranes. Made up of ribosomal RNA (rRNA) and proteins.

Endoplasmic Reticulum

A network of membrane tubes within the cytoplasm of eukaryotic cells. Two forms: Rough ER and Smooth ER.

Golgi Complex

Comprises flattened membrane-bound sacs; facilitates proper folding, modification, and packaging of newly synthesized proteins for trafficking.

Mitochondria

Possesses a double membrane structure; outer membrane is smooth, while the inner membrane forms cristae; functions in ATP production, providing energy for cellular processes.

Lysosomes

Membrane-bound sacs containing hydrolytic enzymes; responsible for digesting various materials such as damaged cell parts or macromolecules.

Vacuoles

Membrane-bound sacs with diverse functions, including storage of water and macromolecules, as well as waste removal.

Chloroplasts

Found in photosynthetic eukaryotic cells like algae and plants; double outer membrane structure and specialized for capturing solar energy and producing sugars through photosynthesis.

Thylakoid

Highly folded membrane compartments organized in stacks called grana; contains chlorophyll pigments and electron transport proteins for light-dependent reactions; increased folding enhances efficiency of reactions.

Stroma

Fluid between inner chloroplast membrane and thylakoids where carbon fixation reactions (Calvin-Benson cycle) occur.

Turgor pressure

Pressure exerted by the cell wall when water flows into vacuoles via osmosis. Turgidity is the optimal state for plant cells.

Apoptosis

Programmed cell death.

Surface Area-to-Volume Ratio

Adequate surface area of the plasma membrane is crucial for efficient material exchange; smaller cells typically exhibit higher surface area-to-volume ratios, facilitating more efficient exchange with the environment.

Phospholipids

Possess both hydrophilic and hydrophobic regions (amphipathic nature); spontaneously form a bilayer in aqueous environments, with tails oriented inward and heads exposed.

Peripheral Proteins

Loosely bound to the membrane surface with hydrophilic charged and polar side groups.

Integral Proteins

Span the membrane with hydrophilic charged and polar side groups on the surface and hydrophobic nonpolar side groups penetrating the bilayer.

Fluid Mosaic Model

Describes the structure of cell membranes as a fluid bilayer of phospholipids with embedded proteins forming a mosaic; lipids and some proteins can shift and flow along the membrane surface or across the bilayer.

Glycoproteins

Carbohydrates attached to membrane proteins.

Glycolipids

Lipids with attached carbohydrates.

Plasmodesmata

Small holes facilitating nutrient, waste, and ion transfer between plant cells.

Concentration Gradient

Solute more concentrated in one area than another; membrane separates two different concentrations of molecules.

Passive Transport

Net movement of molecules from high to low concentration; occurs without metabolic energy (e.g., ATP).

Active Transport

Requires direct input of energy (e.g., ATP); moves molecules from regions of low concentration to high concentration.

Endocytosis

Requires energy to move large molecules into the cell; types include phagocytosis, pinocytosis, and receptor-mediated endocytosis.

Exocytosis

Requires energy to move large molecules out of the cell; internal vesicles fuse with the plasma membrane to secrete large macromolecules out of the cell.

Cotransport

Secondary active transport utilizes energy from an electrochemical gradient to transport two different ions across the membrane through a protein.

Symport

Two different ions are transported in the same direction.

Antiport

Two different ions are transported in opposite directions.

Osmosis

Diffusion of free water across a selectively permeable membrane; large quantities of water move via aquaporins.

Osmolarity

Total solute concentration in a solution.

Tonicity

Measurement of relative solute concentrations between two solutions (inside and outside of the cell).

Hypertonic

More solute and less solvent.

Isotonic

Equal concentrations of solute and solvent.

Hypotonic

Less solute and more solvent.

Plasmolysis

Occurs in plant cells in hypertonic environments.

Flaccid

Occurs in plant cells in isotonic environments.

Turgid

Occurs in plant cells in hypotonic environments.

Autotroph

Capture energy from physical sources (like sunlight) or chemical sources and convert it into energy forms usable by cells.

Heterotroph

Obtain energy from carbon compounds produced by other organisms through metabolism.

Photosynthesis

The process by which organisms capture energy from sunlight and convert it into sugars.

Cellular respiration

Release chemical energy from organic molecules like glucose.

ATP synthase

An enzyme that creates ATP when protons pass through it.

Calvin cycle

The cycle uses ATP, NADPH, and CO2 to produce carbohydrates, which are essential organic products for plants.

Enzymes

Macromolecules that serve as biological catalysts, accelerating biochemical reactions.

Active site

A region where substrate molecules bind and interact.

Substrates

Molecules that can interact with enzymes and bind to their active sites.

Denaturation

Alterations in the conformational or tertiary structure of an enzyme, which can result in loss of enzyme function.

Inhibitors

Competitive inhibitors bind reversibly or irreversibly to the enzyme's active site, competing with the substrate for binding. Noncompetitive inhibitors bind to allosteric sites on enzymes, inducing conformational changes that inhibit enzyme function.

Cell communication

The process where cells send chemical signals directly into adjacent cells, facilitated by modifications in cell membranes and cell walls.

Target cell

The cell receiving the signal.

Ligand

A chemical messenger that binds to a receptor protein on the target cell.

Signal transduction

Cascade relay signals from receptors to cell targets, often amplifying the incoming signals; leads to appropriate responses by the cell, such as cell growth, secretion of molecules, or gene expression.

Second messengers

Such as cyclic AMP, relay and amplify the intracellular signal.

Ligand-Gated Channels

Binding of ligands to ligand-gated channels can cause the channels to open or close, regulating ion flow across the cell membrane.

Quorum sensing

A signal mechanism used by bacteria, where bacteria release signals to neighboring bacteria to detect changes in population density and coordinate their actions as a group in response to environmental changes.

Feedback mechanisms

Organisms utilize feedback mechanisms to regulate their internal environments and adapt to changes in their surroundings; can be negative or positive.

Homeostasis

The process of maintaining a stable internal environment, is crucial for cellular functions.

Negative feedback mechanisms

When a system is disturbed, negative feedback mechanisms work to return it to its target set point, thereby restoring equilibrium.

Positive feedback mechanisms

Amplify responses and processes within biological organisms; instead of restoring equilibrium, positive feedback mechanisms push the variable further from the initial set point, disrupting homeostasis.

Cell Cycle

A meticulously regulated series of events that governs the growth and reproduction of cells; comprises two main phases: Interphase and M-Phase.

Interphase

This phase involves growth and preparation for division. G1, S, and G2.

Mitosis

This process involves the division of the nucleus; ensures the transfer of a complete genome from a parent cell to two genetically identical daughter cells; proceeds through a series of sequential steps: prophase, metaphase, anaphase, and telophase.

Cytokinesis

Following mitosis, cytokinesis occurs, leading to the division of the cytoplasm; ensures the equal distribution of cytoplasmic contents to both daughter cells.

Cyclin-Dependent Kinases (CDKs)

Enzymes are involved in cell cycle regulation; require cyclin binding for activation; phosphorylate substrates to promote various cell cycle activities.

Cyclins

Group of proteins associated with specific cell cycle phases; produced to promote cell cycle progression and degraded to inhibit it; activate cyclin-dependent kinases (CDKs) by binding to them.

Diploid (2n)

Cells containing two full sets of chromosomes, one from each parent.

Haploid (n)

Cells containing only one set of chromosomes.

Meiosis

Meiosis results in daughter cells with half the number of chromosomes as the parent cell; the process involves two rounds of sequential steps: meiosis I and meiosis II.

Crossing Over

Occurs during prophase I of meiosis I; nonsister chromatids of homologous chromosomes exchange segments, resulting in recombinant chromatids; increases genetic diversity by creating novel combinations of alleles on chromosomes.

Random Assortment of Chromosomes

Takes place during metaphase I of meiosis I; the arrangement of homologous pairs determines which chromosomes end up in each gamete; different combinations of chromosomes in gametes increase genetic variation by shuffling genetic material.

Linked Genes

Located close to each other on the same chromosome, tend to be inherited together and are less likely to undergo crossing over during meiosis.

Polygenic traits

Result from the interaction of multiple genes and physiological processes; don't follow Mendelian patterns and instead show additive effects of alleles inherited from each parent.

Phenotypic Variation

The same genotype can result in multiple phenotypes; environmental factors can influence gene expression, leading to different phenotypic outcomes.

Nondisjunction

Where chromosomes fail to separate properly during gamete formation, can result in offspring having an abnormal number of chromosomes.

DNA

And sometimes RNA, serves as the primary source of hereditary material.

Plasmids

Small extra-chromosomal circular DNA molecules.

Semiconservative replication

DNA replication is semiconservative, resulting in a DNA molecule containing one original strand and a newly synthesized complementary strand.

Transcription

Process where an enzyme directs the formation of an mRNA molecule using DNA as a template.

Anticodons

Three-base sequences complementary to mRNA codons.

Translation

The process where an mRNA sequence is used to generate a polypeptide.

Operons

Clusters of genes producing a single mRNA, are controlled by the same regulatory sequence, including the operator, which binds regulatory proteins to inhibit or promote transcription.

Mutations

Changes in the genome, which can be positive, negative, or neutral based on their effect on nucleic acids or proteins and the resulting phenotypes.

Electrophoresis

Gel electrophoresis separates DNA molecules based on size and charge.

Polymerase Chain Reaction (PCR)

PCR amplifies DNA fragments, allowing for the creation of large samples from small initial amounts.

Bacterial Transformation

Bacterial cells uptake foreign DNA, which can be integrated into the chromosome or exist separately as plasmids.

Evolution

The change in the genetic makeup of a population over time and is supported by various lines of evidence.

Natural Selection

A fundamental mechanism driving evolution, where organisms with adaptations suited to their environment have higher chances of survival and reproduction, passing on these adaptations to subsequent generations.

Adaptations

Traits that confer advantages in specific environments, increasing an individual's chances of survival and reproduction.

Evolutionary Fitness

Refers to an organism's ability to survive and produce fertile offspring, measured by reproductive success over several generations.

Selective pressures

Biotic and abiotic factors like disease, predation, climate, and food availability, influence survivability within populations.

Artificial Selection

Process whereby humans selectively breed individuals of other species to enhance desirable traits.