This molecule binds to a receptor to initiate a signal transduction pathway.
What is a ligand?
The molecule that serves as the final electron acceptor in the electron transport chain.
What is oxygen?
The term for the cell membrane's ability to allow some substances to pass while blocking others.
What is selective permeability?
This organelle is the site of ribosome attachment for protein synthesis, but only for proteins destined for membranes, lysosomes, or secretion.
What is the rough endoplasmic reticulum?
The functional group with the formula -OH.
What is a hydroxyl group?
The type of cell signaling that occurs between nearby cells, involving signaling molecules like growth factors.
What is paracrine signaling?
This molecule is the main electron carrier that delivers electrons to the electron transport chain during cellular respiration.
What is NADH?
The lipid molecule that stabilizes the fluidity of the cell membrane.
What is cholesterol?
The inner membrane of this organelle is folded into structures called cristae to increase the surface area for ATP production.
What is the mitochondrion?
The functional group commonly found in amino acids that contains nitrogen.
What is an amino group?
A protein that activates a cascade of intracellular signals by phosphorylating other proteins.
What is a kinase?
The enzyme that generates ATP as protons flow through it during oxidative phosphorylation.
What is ATP synthase?
These proteins span the entire membrane and help transport substances in and out of the cell.
What are integral or transmembrane proteins?
This organelle forms vesicles for exocytosis and is responsible for producing lysosomes by modifying and packaging proteins and lipids.
What is the Golgi apparatus?
The functional group found in fatty acids that makes them acidic.
What is a carboxyl group?
The second messenger produced by adenylyl cyclase that amplifies the signal.
What is cyclic AMP or cAMP?
The process that occurs when oxygen is not present, allowing glycolysis to continue by regenerating NAD+.
What is fermentation?
The process by which large molecules or particles are taken into the cell by vesicle formation.
What is endocytosis?
These organelles, which originated from endosymbiosis, have their own circular DNA and ribosomes, and divide independently of the cell cycle through binary fission.
What are mitochondria and chloroplasts?
The functional group characterized by a phosphate atom bonded to four oxygen atoms.
What is a phosphate group?
This type of receptor undergoes a conformational change when a signal molecule binds, allowing ions to pass through.
What is a ligand-gated ion channel?
This enzyme breaks hydrogen peroxide (H₂O₂) into water and oxygen to protect cells from oxidative damage.
What is catalase?
The term for the combination of lipids and proteins forming the cell membrane’s structural framework.
What is the fluid mosaic model?
Found in some protists, this contractile organelle actively expels excess water to maintain osmotic balance.
What is a contractile vacuole?
The functional group -SH, which helps stabilize protein structure through disulfide bonds.
What is a sulfhydryl group?