Microbial Metabolism (Catabolism)

Flashcards covering main vocabulary from lecture notes on Microbial Metabolism.

Metabolism

All of the chemical reactions in a living organism; provides energy and makes molecules needed for cellular processes.

Catabolism

Breaks down complex molecules, releases energy, and provides building blocks for anabolism.

Anabolism

Uses energy and building blocks to build complex molecules.

Metabolic Pathway

A series of chemical reactions that produce important molecules for the cell.

Catalyst

Speed up a chemical reaction by lowering the activation energy needed to begin the reaction.

Enzyme

Often has a name ending in -ase, is a biological catalyst, is not used up during the reaction, has an active site, acts only on a specific substrate, breaks covalent bonds, and forms new covalent bonds.

Oxidoreductase

Oxidation-reduction reactions.

Transferase

Transfer functional groups.

Hydrolase

Hydrolysis.

Lyase

Removal of atoms without hydrolysis.

Isomerase

Rearrangement of atoms.

Ligase

Joining of molecules; uses ATP.

Apoenzyme

The enzyme protein (may be inactive when alone).

Cofactor

A non-protein component, such as Mg2+.

Coenzyme

An organic cofactor, such as coenzyme A (CoA) in the Krebs cycle.

Holoenzyme

Apoenzyme plus cofactor (whole, active enzyme).

Competitive inhibitors

Fill the active site of an enzyme and compete directly with the substrate.

Noncompetitive inhibitors

Bind to another part of the enzyme (allosteric site) instead of the active site; change the shape of the enzyme and the active site so the enzyme cannot bind the substrate

Ribozyme

An RNA molecule that functions as a catalyst.

Catabolism

Extracts energy from organic compounds and stores it in chemical form (ATP).

Anabolism

Uses energy.

Aerobic Respiration

Requires O2.

Anaerobic Respiration

Does not require O2; may require the absence of O2.

Fermentation

Lactic acid fermentation (produces acid) and alcohol fermentation (produces ethanol and CO2).

Glycolysis

Oxidizes a glucose molecule.

Oxidation-Reduction (Redox) Reactions

One molecule donates one or more electrons and is oxidized; another molecule accepts the electron(s) and is reduced.