Chapter 8 Flashcards
Metabolism
Collection of controlled biochemical reactions that take place within cells.
Metabolic pathway
The coordinated series of chemical reactions on which the product from one reaction becomes the substrate for another reaction.
ATP
Adenosine triphosphate. Energy carrying molecule found in all cells.
Catabolism
Breaking larger molecules into smaller products (exergonic)
Anabolism
Builds large molecules from the smaller products of catabolism. Endergonic (requires more energy than released)
Exergonic
Releases energy. Catabolism. -free energy. Reactants are greater than products.
Endergonic
Require more energy than they release. Anabolism. +free energy. Products are greater than reactants.
Oxidation
Oxidation
Is
Loss of electrons
Reduction reactions (redox)
Redox
Is
Gain of electrons
Electron donor
Release electrons during cellular respiration, release energy.
Electron acceptor
Accepts electrons transported by another compound. Oxygen is the final electron receptor in the electron transport chain.
Oxidation redox reactions
Oxidation is loss of electrons, gain of oxygen or loss of hydrogen. Reduction is gain of electrons, loss of oxygen or gain or hydrogen.
NAD +
Nicotinamide adenine dinucleotide. (NAD+➡️NADH). Coenzyme, electron/hydrogen acceptor.
FAD
Flavin adenine dinucleotide. (FAD➡️FADH2). Electron/hydrogen acceptor.
NADH
nicotinamide adenine dinucleotide (NAD) + hydrogen (H). NAD+➡️NADH. Electron carrier.
FADH2
Flavin adenine dinucleotide. FAD➡️FADH2. Electron carrier.
Phosphorylation
Inorganic phosphate is added to substrate
Substrate-level phosphorylation
Pi comes from other compound.
Oxidative phosphorylation
Redox reaction, e.g. cellular respiration.
Cellular respiration
The process of converting glucose into a form of energy (ATP) that is useable by cells.
Fermentation
Anaerobic respiration. Extraction of energy from carbohydrates in the absence of oxygen.
Reactant
a substance that is present at the start of a chemical reaction.
Product
a substance that is formed as the result of a chemical reaction.
Glycolysis
Splitting of six carbon glucose into three-carbon sugar molecules. Occurs in cytoplasm.
Pyruvic acid
produced by breaking down carbohydrates and sugars (glycolysis). If oxygen is available, pyruvic acid is converted to acetyl coenzyme A that enters the Krebs cycle.
Synthesis of acetyl-coA
Pyruvate—three carbons—is converted to acetyl CoA, a two-carbon molecule attached to coenzyme A. Occurs in mitochondria.
Citric acid cycle
Transfers energy from acetyl-CoA (oxidized) to coenzymes NAD+ and FAD (reduced). Occurs in mitochondria.
Electron transport train
Chain of several electron transport molecules; electrons are passed along chain; released energy is used to form a proton gradient; ATP is synthesized as protons diffuse down gradient, oxygen is final electron acceptor. (Occurs in mitochondria).
Carrier molecules
Pass electrons from one to another to final electron acceptor
Final electron acceptor
Oxygen is the final electron acceptor in an electron transport chain
Proton gradient
Energy from electrons used to pump protons (H+) across the membrane
Electronegativity
a chemical property that describes the tendency of an atom or a functional group to attract electrons toward itself.
ATP synthase
mitochondrial enzyme localized in the inner membrane, where it catalyzes the synthesis of ATP from ADP and phosphate.
Chemiosmosis
The movement of ions across a selectively permeable membrane, down their electrochemical gradient
Aerobic respiration
Oxygen serves as the final electron acceptor
Anaerobic respiration
Molecule other than oxygen serves as final electron acceptor
Fermentation
the extraction of energy from carbohydrates in the absence of oxygen
Alcohol fermentation
process which converts sugars such as glucose, fructose, and sucrose into cellular energy, producing ethanol and carbon dioxide as by-products.
Lactic acid fermentation
the type of anaerobic respiration carried out by yogurt bacteria (Lactobacillus and others) and by your own muscle cells when you work them hard and fast.
Metabolite
A substance made or used when the body breaks down food, drugs or chemicals, or its own tissue