Ultimate AP Biology Vocabulary Review

polar

Molecule with partial charges. Mixes with water.

nonpolar

No partial charges. Do not mix with water.

cohesion

Water molecules sticking to each other.

adhesion

Water molecules sticking to other surfaces.

solute

Something dissolved in a solution.

solvent

Dissolving agent of a solution.

isomers

Same atoms but different arrangement.

glucose

Monomer for starch and glycogen.

cellulose

Carbohydrate component of plant cell walls.

starch

Storage polysaccharide of plants.

glycogen

Extremely branched polymer of glucose.

chitin

Polysaccharide found in arthropod exoskeletons and fungal cell walls.

triglyceride

Glycerol and three fatty acids.

steroids

Made of four rings of carbon.

cholesterol

Steroid common in cell membranes, also in many hormones.

peptide bond

Bonds that connect amino acids.

disulphide bridges

Reinforce tertiary structure.

primary structure

Chain of amino acids.

secondary structure

Either an alpha helix or beta pleated sheet.

tertiary structure

Results from interactions between side chains.

quaternary structure

Results from two or more polypeptide subunits.

purines

Bases with a double-ring structure.

pyrimidines

Bases with a single-ring structure.

dehydration synthesis

Condensation reaction where molecules are connected by loss of a water molecule.

hydrolysis

Reaction where water split into two hydrogens and one oxygen; this breaks a polymer.

anabolism

Metabolic pathways that construct molecules, requiring energy.

catabolism

Metabolic pathways that break down molecules, releasing energy.

natural selection

A population can change over time if individuals with more fit traits leave more offspring than less fit individuals.

artificial selection

Humans modifying species for desired traits through selective breeding.

decent with modification

Darwin's way of referring to evolution.

fitness

advantage having a better chance of surviving in a given environment and will leave more offspring.

gene pool

All the genes in a given population at a given time.

allele frequency

Proportion of an allele in a gene pool.

Hardy-Weinberg equation

Helps measure changes in allele frequencies over time. Provides an "ideal" population to use as a basis of comparison.

mutation

Changes in the nucleotide sequence in DNA.

recombination

Crossing over and shuffling of genes during meiosis.

directional selection

Shift toward a favorable variation.

disruptive selection

Shift toward the extremes.

stabilizing selection

Shift that favors the mean.

speciation

Origin of new species and the source of biological diversity.

endosymbiotic theory

Ancestors of mitochondria and plastids was prokaryotes thatcame to live in a host cell.

the three-domain system

Domains Bacteria, Archae, and Eukarya.

plasmolyze

When the membrane shrinks away from the cell wall as a result of water loss.

lyse

Cell bursting.

plasmids

Small rings of DNA found naturally in some bacterial cells in addition to the main bacterial chromosome. Can contain genes for antibiotic resistance, or other "contingency" functions.

archaea

Domain of unicellular prokaryotes that have cell walls lacking peptidoglycan. Like eukaryotes, DNA contains histone proteins.

ecology

Study of interactions between organisms and the environment.

producer

Autotroph.

primary consumer

Herbivore.

organelles

Structures specialized to perform distinct processes within a cell.

cytosol

The soluble portion of the cytoplasm, which includes molecules and small particles, such as ribosomes, but not the organelles covered with membranes.

eukaryotic cells

Contain a nucleus and other organelles that are bound by membranes.

cytoplasm

The region of the cell between the cell membrane and the nucleus.

plasma membrane

The membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell's chemical composition.

nuclear envelope

Double membrane perforated with pores that control the flow of materials in and out of the nucleus.

chromosomes

A threadlike, gene-carrying structure found in the nucleus. Consists of one very long DNA molecule and associated proteins.

chromatin

The readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins.

nucleolus

Small, dense region within most nuclei in which the assembly of proteins begins.

endomembrane system

A network of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles.

vesicle

Small membrane-bound sac that functions in moving products into, out of, and within a cell.

smooth ER

Synthesis of lipids, phospholipids and steroid sex hormones-help detoxify drugs and poisons (liver cells).

rough ER

A network of interconnected membranous sacs in a eukaryotic cell's cytoplasm; covered with ribosomes that make membrane proteins and secretory proteins.

glycoprotein

A protein with one or more carbohydrates covalently attached to it.

Golgi apparatus

Stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum.

phagocytosis

Process in which extensions of cytoplasm surround and engulf large particles and take them into the cell.

lysosome

A cell organelle that contains digestive enzymes.

contractile vacuoles

A membranous sac that helps move excess water out of the cell.

mitochondria

The organelles in which nutrients are converted to energy.

chloroplasts

Organelles that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis.

peroxisome

A microbody containing enzymes that transfer hydrogen from various substrates to oxygen, producing and then degrading hydrogen peroxide.

cristae

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.

thylakoids

Membranous structures within a chloroplast that serve as the site for light harvesting in photosynthesis.

stroma

The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water.

cytoskeleton

Network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement.

cell wall

Strong layer around the cell membrane in plants, algae, and some bacteria.

diffusion

When a substance moves from an area of higher concentration to an area of lower concentration. Due to entropy.

osmosis

The diffusion of water through a selectively permeable membrane.

passive transport

Transport of a substance across a cell membrane by diffusion. No cell energy required.

active transport

When a cell gets materials or excretes them by using its own energy, usually through ATP; going against a concentration gradient.

hypertonic

Describes a solution that has a greater concentration of total solute.

hypotonic

Describes a solution that has a lesser concentration of total solute.

isotonic

Describes solutions that have an equal concentration of total solutes.

plasmolysis

This happens when a cell shrinks inside its cell wall while the cell wall remains intact.

flaccid

This happens when water moves, but the amount within the cell is constant; no pressure builds.

cytolysis

This happens when a cell swells until pressure bursts it, resulting in cell death.

crenation

This happens when a cell shrinks and shrivels; can result in cell death if severe.

water potential

The physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure.

solute potential

This measurement has a maximum value of 0; it decreases as the concentration of a solute increases.

pressure potential

This measurement has a minimum value of 0 (when the solution is open to the environment); it increases as pressure increases.

selective permeability

A property of a plasma membrane that allows some substances to cross more easily than others.

amphipathic

Molecules are said to be this when it has regions that are both hydrophilic and hydrophobic.

fluid mosaic model

Structural model of the plasma membrane where molecules are free to move sideways within a lipid bilayer.

integral proteins

Integral proteins that span the membrane.

transmembrane proteins

Integral proteins that span the membrane.

peripheral proteins

The proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane.

transport

An exchange of molecules (and their kinetic energy and momentum) across the boundary between adjacent layers of a fluid or across cell membranes.

signal transduction

A series of molecular changes that converts a signal on a target cell's surface to a specific response inside the cell.

cell-cell recognition

The function of membrane proteins in which some glycoproteins serve as ID tags that are recognized by membrane proteins of other cells.

intercellular joining

The function of membrane proteins in which membrane proteins of adjacent cells hook together, as in gap junctions or tight junctions.

glycolipids

Membrane carbohydrates that are covalently bonded to lipids.