Energy and Metabolism
What is the term for all chemical reactions that occur within a living organism to maintain life?
What is metabolism?
What molecule serves as the primary energy currency in cells?
What is ATP (adenosine triphosphate)?
In which organelle does the citric acid cycle occur?
What is the mitochondrion (specifically the mitochondrial matrix)?
What is the main purpose of fermentation in cells?
What is to regenerate NAD⁺ to allow glycolysis to continue in the absence of oxygen?
What part of an enzyme binds to its substrate?
What is the active site?
State the first law of thermodynamics.
What is energy cannot be created or destroyed, only transformed or transferred?
Where in the cell does glycolysis take place?
What is the cytoplasm?
What molecule carries the acetyl group into the citric acid cycle?
What is Acetyl-CoA?
Name the type of fermentation that occurs in animal muscle cells during oxygen shortage.
What is lactic acid fermentation?
How do enzymes speed up chemical reactions?
By lowering the activation energy needed for the reaction.
What type of energy is stored within the bonds of food molecules?
What is chemical energy?
How many net ATP molecules are produced per glucose molecule during glycolysis?
What is 2 ATP?
Name two high-energy electron carriers produced by the citric acid cycle.
What are NADH and FADH₂?
What toxic byproduct is produced during alcohol fermentation?
What is ethanol?
What is competitive inhibition in enzyme regulation?
When an inhibitor molecule competes with the substrate for binding to the enzyme’s active site.
What type of reaction requires energy input and is non-spontaneous?
What is an endergonic reaction?
What is the name of the three-carbon molecule produced at the end of glycolysis?
What is pyruvate?
What is the final electron acceptor in the electron transport chain?
What is oxygen?
Which enzyme catalyzes the conversion of pyruvate to lactic acid?
What is lactate dehydrogenase?
Name a cofactor that is an organic molecule helping enzyme function.
What is a coenzyme (often a vitamin)?
Define entropy in the context of the second law of thermodynamics.
What is a measure of disorder or randomness, which increases in every energy transfer?
Why can't cells store significant amounts of free energy as ATP?
Because excess free energy would increase heat, denature proteins, and damage the cell.
What process uses the electrochemical gradient of hydrogen ions to produce ATP?
What is chemiosmosis?
What distinguishes anaerobic respiration from fermentation?
Anaerobic respiration uses an inorganic molecule other than oxygen as the final electron acceptor, while fermentation uses organic molecules.
What is feedback inhibition?
What is when the product of a reaction inhibits an earlier step’s enzyme to regulate its own production?