Question

which processes require oxygen? check all that apply.
conversion of pyruvic acid to acetyl coa
conversion of pyruvic acid to lactic acid
conversion of pyruvic acid to alcohol
production of carbon dioxide in the citric acid cycle
production of water in the electron transport chain
production of pyruvic acid in glycolysis

Explanation:

1. Conversion of pyruvic acid to Acetyl CoA: This is part of aerobic respiration (link reaction), requiring oxygen - dependent pathways (though the reaction itself doesn't use O₂ directly, it's part of aerobic metabolism which needs O₂ overall).
2. Production of CO₂ in citric acid cycle: The citric acid cycle is an aerobic process (part of cellular respiration that requires oxygen availability for full operation, even though the cycle itself doesn't use O₂ directly, it's dependent on the overall aerobic pathway).
3. Production of water in electron transport chain: The electron transport chain uses oxygen as the final electron acceptor to form water, so this process requires oxygen.

The other processes: conversion of pyruvic acid to lactic acid (lactic acid fermentation, anaerobic), conversion of pyruvic acid to alcohol (alcoholic fermentation, anaerobic), and production of pyruvic acid in glycolysis (glycolysis is anaerobic - can occur without O₂) do not require oxygen.

Answer:

• conversion of pyruvic acid to Acetyl CoA
• production of carbon dioxide in the citric acid cycle
• production of water in the electron transport chain