Single-celled organisms that store genetic information within a nucleoid; lack membrane-bound organelles. May use flagella for movement.
What is a prokaryote?
The difference in concentration of a soluble molecule across a semi-permeable membrane.
What is a concentration gradient?
Solutes will naturally want to move from [high] --> [low]!
What is a receptor?
Organic molecule that acts as a source of energy for the body by storing potential energy in phosphate bonds.
What is ATP/adenosine triphosphate?
A protein embedded in a cell membrane that reaches across/spans the width of it.
What is a transmembrane protein?

The network of protein fibers that are responsible for maintaining a cell's shape
What is the cytoskeleton?
(Study microtubules + microfilaments)
Channel proteins that selectively move water (H2O) across cell membranes.
What is an aquaporin?
A molecule that acts as a specific chemical signal to a receptor protein by having a 3D shape that fits into its binding site.
What is a ligand?
The first step of in both cellular respiration or fermentation, turns 1 glucose into 2 pyruvate.
1 glucose + 2 ATP + 2 NAD+ --> 2 pyruvate, 2 NADH, 4 ATP
What is glycolysis?
Chemical process where a reactant gains electrons, often portrayed as forming a bond with hydrogen (H+).
What is reduction?
Phospholipid bilayer that encloses the cytosol and cellular organelles, separating the cytoplasm from the extracellular environment. Fluidity determined by ratio of saturated/unsaturated lipids (and presence of cholesterol).
What is the cell membrane?
Cell junctions that act as localized "spot welds"; cells are "glued" together at these spots.
What are desmosomes?
Chemical signals that bind to/affect cells near the releaser cell.
What are paracrine signals?
Chemical process where a reactant loses electrons, often portrayed as breaking a bond with hydrogen (H+).
What is oxidation?
A type of transmembrane protein receptor that is responsible for producing a variety of signals for a cell
What is a G protein-coupled receptor?
Vesicles that contains digestive enzymes, used by cell to break down macromolecules into monomers.
What is a lysosome?
Transmembrane protein that uses active transport to move 3 sodium (Na+) ions across the membrane while moving 2 potassium (K+) across the cell membrane in the opposite direction.
What is the sodium-potassium ATPase pump?
The multi-step molecular pathway triggered by the binding of a ligand in order to carry out a specific cellular response.
What is a signal transduction pathway?
ATP-generating metabolic process that does NOT use oxygen. Only produces 2 ATP per 1 glucose molecule.
What is fermentation/anerobic respiration?
Inhibiting molecules that chemically resemble ligands, can bind to and block their intended receptors.
What are antagonists?
Cell organelle made of a phospholipid bilayer - synthesizes lipids, contains NO ribosomes, chemically modifies small molecules
What is the smooth ER/endoplasmic reticulum?
Molecules move through channel/carrier proteins in direction of a chemical gradient established by another protein that uses ATP to move molecules against their concentration gradient.
What is secondary active transport?
A protein that phosphorylates other targeted proteins.
What is a protein kinase?
ATP-generating metabolic process that requires oxygen. Produces ~36 ATP per 1 glucose molecule.
Takes place in 3 main stages: glycolysis (+ link reaction), Krebs cycle, and electron transport chain.
What is (aerobic) cellular respiration?
Cell junctions made of groups of transmembrane channel proteins that physically link neighboring cells and allow direct exchange of communication signals.
What are gap junctions?