FREE AP-Micro (Microbiology) Microbial Metabolism Questions and Answers
Which molecule acts as the primary energy carrier in microbial cells?
ATP is the primary energy carrier in all living cells. It stores energy in its high-energy phosphate bonds and releases it when needed for cellular processes. Glucose is a source of energy, while NADH and pyruvate are intermediates in metabolic pathways.
In anaerobic respiration, what acts as the terminal electron acceptor?
In anaerobic respiration, molecules other than oxygen (e.g., nitrate, sulfate, or carbon dioxide) act as terminal electron acceptors. Oxygen is used only in aerobic respiration.
What is the primary purpose of fermentation in microorganisms?
Fermentation allows cells to regenerate NAD+ from NADH in the absence of oxygen, ensuring that glycolysis can continue to produce small amounts of ATP. It does not directly produce significant ATP but enables energy production under anaerobic conditions.
Which process generates the most ATP in microbial metabolism?
Oxidative phosphorylation, which occurs in the electron transport chain, generates the most ATP by using a proton gradient to drive ATP synthesis. Glycolysis and the Krebs cycle produce smaller amounts of ATP directly.
What is the end product of glycolysis?
Glycolysis breaks down glucose into two molecules of pyruvate, producing a net gain of ATP and NADH in the process. Pyruvate can then enter the Krebs cycle (in aerobic conditions) or fermentation (in anaerobic conditions).