Chapter 8 Metabolic Pathways

Question 1

Cellular Respiration

Answer 1

process organisms undergo to convert glucose to energy

• involves 4 stages:
  1. Glucose catabolism (usually glycolysis)
  2. Transition or Bridge Reaction
  3. Krebs Cycle
  4. Electron Transport
• may occur aerobically (most efficient) or anaerobically

Question 2

Glycolysis

Answer 2

-Location: cytoplasm
-Oxygen Requirement: none
-Reactant: glucose
-By Products: NADH , ATP (4-2=2 net)
-Final Product: 2 pyruvates (C3)
(becomes the reactant of next step)

Question 3

Metabolic Pathway: Aerobic Respiration

Answer 3

C6H12O6 + 6O2–> 6 CO2 + 6H2O + ATP
-aerobic catabolism of nutrients to carbon dioxide, water, and energy, and involves an electron transport system in which molecular oxygen is the final electron acceptor

Question 4

Aerobic Respiration: Transition/ Bridge Reaction

Answer 4

2nd Stage
-Location: 
>Prokaryotic Cell: cytoplasm 
>Eukaryotic Cell: mitochondrial matrix 
-Reactant: Pyruvate (C3)
-Products: CO2 NADH
-Final Product: Acetyl CoA (C2) 
(product of step 2; reactant of step 3 in pathway)

Question 5

Aerobic Respiration: Krebs Cycle

Answer 5

3rd Stage
C2--> 0C
-Location: 
>Prokaryotic Cell: Cytoplasm 
>Eukaryotic Cell: Mitochondrial Matrix
-Reactant: Acetyl CoA (C2)
-Products: CO2 ATP
-Final Products: NADH FADH2
(product of step 3; reactant of step 4)

Question 6

Aerobic Respiration: Electron Transport

Answer 6

4th Stage
-Location: 
>Prokaryotic Cell: plasma membrane
>Eukaryotic Cell: mitochondrial inner membrane
-Reactant: NADH FADH2
-Products: ATP
-Final Product: H20
-Final Electron Acceptor: Oxygen

Question 7

Metabolic Pathway: Anaerobic Respiration

Answer 7

-Location:
>Prokaryotic: plasma membrane
>Eukaryotic: mitochondrial inner membrane
-Reactant: NADH FADH2
-Products: Less ATP
-Final Product: NO2, N2O, N2, H2S, CH4
-Final Electron Acceptor: Not Oxygen (inorganic oxygen containing molecules)

Question 8

Metabolic Pathway: Acid + Alcohol Fermentation

Answer 8

• Species Specific
• Heterolactic: yields carbon dioxide and ethanol in addition to lactic acid
• Homolactic: one molecule of glucose is ultimately converted to two molecules of lactic acid

Question 9

Fermentation: Heterolactic

Answer 9

yields carbon dioxide and ethanol in addition to lactic acid

Question 10

Fermentation: Homolactic

Answer 10

one molecule of glucose is ultimately converted to two molecules of lactic acid