Vocab #2 Flashcards
(54 cards)
Catabolic pathway
A metabolic pathway that releases energy by breaking down complex molecules to simpler molecules
Anabolic pathway
A metabolic pathway that consumes energy to synthesize a complex molecule from simpler molecules
Oxidation
The complete or partial loss of electrons from a substance involved in a redox reaction
Reduction
The complete or partial addition of electrons to a substance involved in a redox reaction
Exergonic
A spontaneous chemical reaction, in which there is a net release of free energy
Endergonic
A non spontaneous chemical reaction, in which free energy is absorbed from the surroundings
ATP
An adenine-containing nucleotide triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells.
Catalyst
A chemical agent that selectively increases the rate of a reaction without being consumed by the reaction.
Enzyme
A macromolecule serving as a catalyst, a chemical agent that increases the rate of a reaction without being consumed by the reaction. Most are proteins.
Activation Energy
The amount of energy that reactants must absorb before a chemical reaction will start; also called free energy of activation
Substrate
The reactant on which an enzyme works
Active Site
The specific region of an enzyme that binds the substrate and that forms the pocket in which catalysis occurs
Competitive inhibitor
A substance that reduces the activity of an enzyme by entering the active site in place of the substrate, whose structure it mimics.
Noncompetitive inhibitor
A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing the enzyme’s shape so that the active site no longer effectively catalyzes the conversion of substrate to product
Allosteric regulation
The binding of a regulatory molecule to a protein at one site that affects the function of the protein at a different site
Feedback inhibition
A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway
Cellular respiration
The catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules and use an electron transport chain for the production of ATP
Photosynthesis
The conversion of light energy to chemical energy that is stored in sugars or other organic compounds; occurs in plants, algae, and certain prokaryotes
Chemiosmosis
An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. Under aerobic conditions, most ATP synthesis in cells occurs by this process
Citric acid cycle (krebs cycle)
A chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA (derived from pyruvate) to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and in the cytosol of prokaryotes; together with pyruvate oxidation, the second major stage in cellular respiration
Glycolysis
A series of reactions that ultimately splits glucose into pyruvate. It occurs in almost all living cells, serving as the starting point for fermentation or cellular respiration.
Substrate-level
The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.
Phosphorylation
The process of generating ATP from ADP and phosphate by means of chemiosmosis, using a proton-motive force generated across the thylakoid membrane of the chloroplast or the membrane of certain prokaryotes during the light reactions of photosynthesis.
Oxidative phosphorylation
The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.
