chapter 7 (bioquest 8)

Question 1

cellular respiration (formula)

Answer 1

C(6)H(12)O(6) + 6O(2) –> (enzymatic action) 6CO(2) + 6H(2)O + ATP

Question 2

2 stages of cellular respiration

Answer 2

Glycolysis and Aerobic Respiration

Question 3

Glycolysis

Answer 3

takes place in the cytosol, converts glucose (6-carbon compound) into two 3-carbon compounds called pyruvic acid. 2ATP are also produced (2ATP go in and 4 come out). anaerobic process (no oxygen)

Question 4

what happens after glycolysis (2 options)

Answer 4

fermentation (anaerobic) or aerobic respiration (aerobic)

Question 5

fermentation (2 main types)

Answer 5

lactic acid fermentation and alcohol fermentation

Question 6

lactic acid fermentation

Answer 6

a hydrogen atom from NADH is transferred to pyruvic acid turning it into lactic acid (3-carbon molecule). In this process the NADH is turned into NAD+

Question 7

Alcohol fermentation

Answer 7

CO(2) is removed from pyruvic acid, leaving a 2-carbon compound. 2 hydrogen atoms (from NADH) are added to the 2-carbon compound creating ethyl alcohol (2-carbon compound)

Question 8

efficiency of glycolysis

Answer 8

energy required to make atp/energy released by oxidation of glucose = (2 x 7kcal/686 kcal) x 100 = 2%

Question 9

Aerobic respiration (2 stages)

Answer 9

the krebs cycle and the electron transport chain

Question 10

before the krebs cycle begins…

Answer 10

pyruvic acid diffuses into the mitochondrial matrix from the cytosol and reacts with a molecule called coenzyme A (CoA: a 2 carbon compound). CO(2) is given off

Question 11

the krebs cycle

Answer 11

• citric acid (6 carbon compound) breaks down into a 5-carbon compund
• CO(2) is released
• goes to make a 4-carbon compound (oxaloacetic acid)
• picks up a 2-carbon compund (Acetyl CoA)
• cycle begins agian
• during cycle NAD+ –> NADH + H+
• FAD –> FADH(2)
• ADP –> ATP
• 2ATP are formed in this cycle

Question 12

electron transport chain

Answer 12

• NADH and FADH(2) donate e- to chain
• e- lose energy as they move along chain
• energy is used to pump H+ from the matrix (causing a concentration and electrical gradient-potential energy source)
• ATP synthase harnesses the potential energy source to undergo chemiosmosis and produce ATP
• oxygen is the final electron and proton acceptor to make H(2)O

Question 13

importance of oxygen in electron transport chain

Answer 13

oxygen is the final acceptor of electrons and protons to for H(2)O. w/o the final acceptor the electron transport chain will stop

Question 14

cellular respiration total yield of ATP

Answer 14

glucose
Glycolysis
-->2NADH -->6ATP
-->2ATP
Pyruvic acid
-->2NADH -->6ATP
Krebs Cycle
-->6NADH -->18ATP
-->2FADH(2) -->4ATP
-->2ATP

Total: 38 ATP

Question 15

Efficiency of Cellular Respiration

Answer 15

energy required to make ATP/energy released by oxidation of C(6)H(12)O(6)
= (38 x 7 keal/686 keal) x 100 = 39%