Exam 3: Cellular Respiration

Question 1

cellular respiration

Answer 1

the catabolic (breakdown) pathways in which the chemical bond energy in organic molecules is released and trapped to build ATP

Question 2

chemiosmosis

Answer 2

an energy-coupling process in which the diffusion of protons through the ATP synthase protein complex drives ATP synthesis

Question 3

ATP synthase

Answer 3

a complex of membrane proteins that functions in ATP synthesis from ADP and a phosphate, using energy from protons flowing through the synthase from high concentration to low concentration

Question 4

redox reaction

Answer 4

a chemical reaction in which an electron is transferred from one chemical substrate to another; gain of electrons is reduction, and loss of electrons is oxidation

Question 5

electron transport chain

Answer 5

a series of membrane molecules that are reduced and oxidized as electrons move sequentially towards more electronegative acceptors, losing potential energy at each step

Question 6

FAD (flavin adenine dinucleotide)

Answer 6

a coenzyme carrier that serves as an electron shuttle as it is reduced to FADH2 in the Krebs cycle and oxidized back to FAD in the electron transport chain

Question 7

NAD+ (nicotinamide adenine dinucleotide)

Answer 7

a coenzyme carrier that serves as an electron shuttle as it is reduced to NADH (with H+) in glycolysis and the Krebs cycle and is oxidized back to NAD+ in the electron transport chain or during fermentation

Question 8

glycolysis

Answer 8

a pathway of ten cytosolic reactions that split glucose and oxidize it to form pyruvic acid while producing ATP and reduced NADH; the first major stage in cellular respiration

Question 9

Krebs cycle or citric acid cycle

Answer 9

a pathway of eight reactions that oxidize acetyl to carbon dioxide, producing several molecules of reduced NADH and also some ATP and reduced FADH2; the second major stage in cellular respiration

Question 10

fermentation

Answer 10

an anaerobic process in which pyruvate from glycolysis is converted to other organic molecules to provide recovery of oxidized NAD+

Question 11

oxidative phosphorylation

Answer 11

the production of ATP by ATP synthase, joining ADP to a phosphate ion in solution by condensation, using energy from the proton gradient derived from redox reactions in the electron transport chain

Question 12

substrate-level phosphorylation

Answer 12

the production of ATP that occurs when an enzyme transfers a phosphate group from another organic substrate directly onto ADP

Question 13

mitochondria

Answer 13

the organelle in eukaryotic cells where aerobic respiration reactions occur, with Krebs Cycle enzymes in the mitochondrial matrix and electron transport chain and ATP synthase molecules located in the inner membrane

Question 14

aerobic

Answer 14

a metabolic process or organism that requires oxygen gas

Question 15

anaerobic

Answer 15

a metabolic process or organism that does not require oxygen gas

Question 16

4 major processes in respiration and where they take place in the cell

Answer 16

1. Glycolysis - cytoplasm
2. Acetyl CoA formation - mitochondria
3. Krebs Cycle - primarily in the matrix
4. Oxidative phosphorylation - inner membrane of mitochondria