Bio Ch 8

Question 1

Cellular respiration

Answer 1

process by which cells acquire energy by breaking down nutrient molecules produced by photosynthesizers

Question 2

NAD+

Answer 2

coenzyme of oxidation-reduction (AKA redox coenzyme)

Question 3

FAD

Answer 3

coenzyme of oxidation-reduction; sometimes used instead of NAD+; accepts 2 electrons and 2 hydrogen ions (H+) to become FADH2

Question 4

Anaerobic

Answer 4

does not require the presence of oxygen, like glycolysis (takes place outside the mitochondria)

Question 5

Aerobic

Answer 5

requires oxygen; preparatory reaction, citric acid cycle, and ETC take place inside the mitochondria, where oxygen is the final acceptor of electrons

Question 6

Glycolysis

Answer 6

“sugar-splitting”; breakdown of glucose to 2 molecules of pyruvate (two 3-carbon molecules); oxidation results in NADH and provides enough energy for the net gain of two ATP molecules

Question 7

Preparatory (prep) reaction

Answer 7

takes place in the matrix of the mitochondria; pyruvate is broken down from a 3-carbon to a 2-carbon acetyl group, and a 1-carbon CO2 molecule is released; converts products from glycolysis into products that enter the citric acid cycle

Question 8

Citric Acid Cycle

Answer 8

takes place in the matrix of the mitochondrion; each 2-carbon acetyl group matches up with a 4-carbon molecule, forming two 6-carbon citrate molecules; produces 1 ATP per turn; AKA Krebs Cycle, after Hans Krebs, the chemist who worked out the fundamentals of the process in the 1930’s

Question 9

Electron Transport Chain (ETC)

Answer 9

series of carriers on the cristae of the mitochondria (or in the plasma membrane of aerobic prokaryotes); NADH & FADH2 give up their high-energy electrons to the chain; energy is released and captured as the electrons move from a higher-energy to a lower-energy state during each redox reaction; later, this energy is used for the production of ATP by chemiosmosis; after oxygen receives electrons at the end of the chain, it combines with hydrogen ions (H+) and becomes water

Question 10

Fermentation

Answer 10

anaerobic process which results in the net gain of only 2 ATP per glucose molecule

Question 11

Glycolysis

Answer 11

takes place within the cytoplasm outside the mitochondria; breakdown of 6-carbon glucose to two 3-carbon pyruvate molecules; occurs universally in organisms; most likely evolved before the citric acid cycle and the ETC; series of 10 reactions

Question 12

Substrate-level ATP Synthesis (Substrate-level phosphorylation)

Answer 12

enzyme passes a high-energy phosphate to ADP, ATP results; example of coupling (energy-releasing reaction is driving forward an energy-requiring reaction on the surface of the enzyme)

Question 13

Mitochondrion

Answer 13

has a double membrane with an intermembrane space (between the outer and inner membrane); powerhouses of the cell

Question 14

Cytochrome

Answer 14

protein that has a tightly bound heme group with a central atom of iron, the same as hemoglobin does

Question 15

Chemiosmosis

Answer 15

ATP production is tied to the establishment of an H+ gradient

Question 16

Catabolism

Answer 16

metabolic process that breaks down large molecules into smaller ones

Question 17

Anabolism

Answer 17

chemical reaction in which smaller molecules (monomers) are combined to form larger molecules (polymers)

Question 18

Metabolic pool

Answer 18

metabolites that are the products of and/or the substrates for key reactions in cells, allowing one type of molecule to be changed into another type, such as carbohydrates converted to fats

Question 19

Deamination

Answer 19

removal of the amino group