5 Microbial Metabolism Free Online FlashCards

How do catabolism and anabolism differ?

Catabolism breaks molecules down and captures energy; anabolism uses energy and small precursors to build cellular components.

What do enzymes do in cellular reactions?

An enzyme binds particular substrates and lowers the activation energy needed for a reaction. It is not consumed by the reaction.

What is feedback inhibition?

Feedback inhibition occurs when a pathway's end product inhibits an enzyme earlier in that pathway.

What role does ATP play in microbial cells?

ATP is an immediate energy carrier that couples energy-releasing reactions to energy-requiring cellular work.

How do NADH, FADH₂, and NADPH commonly differ in function?

NADH and FADH₂ commonly carry electrons from catabolic reactions; NADPH widely supplies reducing power for biosynthesis.

What distinguishes phototrophs from chemotrophs?

Phototrophs obtain energy from light; chemotrophs obtain energy from chemical reactions. These terms describe energy sources.

What distinguishes autotrophs from heterotrophs?

Autotrophs build cellular carbon from CO₂; heterotrophs obtain carbon from organic compounds.

How does fermentation support continued glycolysis?

Fermentation makes ATP by substrate-level phosphorylation and regenerates NAD⁺ so glycolysis can continue. It does not use an electron transport chain.

How does fermentation's ATP yield compare with respiration?

Fermentation yields generally less ATP per sugar than respiration. Its ATP is made by substrate-level phosphorylation.

What products are commonly associated with yeast fermentation?

Yeasts commonly produce ethanol and carbon dioxide; lactic acid bacteria can produce lactate.

What is the terminal electron acceptor in aerobic respiration?

Aerobic respiration uses oxygen as the terminal electron acceptor.

What defines anaerobic respiration?

Anaerobic respiration uses an electron transport chain and an external terminal acceptor other than oxygen, such as nitrate or sulfate.