AP Biology - aerobic respiration and glycolysis

Question 1

What is aerobic respiration?

Answer 1

• refers to pathways that require oxygen in order to proceed and can be represented by:
  C6H12O6(s) + 6O2(g) 🡪 6CO2(g) + 6H2O (l) + energy
• aerobic respiration is a catabolic pathway that requires the use of oxygen for reaction to proceed

Question 2

what is substrate level phosphorylation

Answer 2

• at various steps in the glycolytic pathway, a phosphate group is removed from a substrate molecule and combined with an ADP molecule to form ATP

Question 3

information about substrate level phosphorylation

Answer 3

• When oxygen is available, pyruvates from glycolysis are transported across the outer and inner mitochondrial membranes into the mitochondrial matrix. The three-carbon pyruvate molecules undergoes oxidation
• The products of pyruvate oxidation produce 2 acetyl-CoA and 2 NADH which is a necessary reactant to begin the Krebs cycle
• In the krebs cycle, a series of reduction reactions occur to produce 6 NADH and 2 FADH2, and 2 ATP
• All the NADH and FAdh2 are used in oxidative phosphorylation to produce 32 or 34 ATP through the use of electron transport chains
• In total, a maximum of 38 molecules of ATP can be generated by the breakdown of one molecule of glucose through the overall process of aerobic respiration

Question 4

What is glycolysis?

Answer 4

• Glycolysis simply is the metabolic pathway that breaks glucose down to a pyruvate
• There are 10 reactions that occur during glycolysis
• Glycolysis occurs in the cytoplasm and then proceeds into the mitochondria for further breakdown

Question 5

steps of glycolysis reactions 1-4

Answer 5

Reactions 1-2:
Two molecules of ATP are used to phosphorylate substrate molecules
ATP comes from other reactions

Reaction 4:
The six carbon compound, fructose 1,6-bisphopshate, is split into two different three carbon compounds: DHAP and G3P

Question 6

Glycolysis reactions 5-7

Answer 6

Reaction 5:
DHAP is converted into a second G3P and each of the two G3P molecules proceeds through reactions 6 to 10

Reaction 6:
An inorganic phosphate group is added to G3P, and an NAD+ molecules is reduced to form NADH
This reaction proceeds twice for the two G3P molecules produced
The reaction results in two 1,3-bisphosphoglycerate (BPG)

Reaction 7:
ADP is converted to ATP by substrate level phosphorylation
The products of the reaction are two-3-phosphoglycerate

Question 7

glycolysis reactions 8-10

Answer 7

Reaction 8 and 9
The three carbon substrate molecules are rearranged in a water molecule is removed through condensation
This results in 2 phosphoenolpyruvate

Reaction 10:
A molecule of ADP is converted to ATP by substrate level phosphorylation
This process again occurs twice resulting in 2 ATP
The products of the reaction are two pyruvates