Lecture #9- Cellular Respiration

Question 1

what is cellular metabolism and what is the point of it

Answer 1

• sum of all chemical rxns in the cell
• catabolic rxn to release energy stored in organic bonds of glucose to make AT by osphos

Question 2

where does glycolysis, Kreb’s/citirc acid cycle, and ETC and oxphos happen

Answer 2

• cytoplasm
• in the matrix of mitochondrion
• across the mitochondria inner membrane

Question 3

define
- anaerobic: obligate and aerotolerant
- aerobic: facultative and obligate

Answer 3

ana:
- obligate: oxygen is toxic
- aerotolerant: do not use O2

aero:
- obligate: requires O2
- Facultative: uses O2 when avail

Question 4

energy investment phase of glycolysis

Answer 4

• point: begin oxidation of glucose
• first 5 rxns
• 1st rxn: hexokinase = kinase: enzyme that phosphorylates (adds an inorganic phosphate tp glucose to make it more reactive)
• 3rd rxn: phosphofructosekinase = main regulatory step
• both steps uses ATP to attach a Pi to make it more reactive
• ends up with glucose split into 2x3C molecules

Question 5

energy payoff phase of glycolysis

Answer 5

• each rxn happens 2 times
• NADH produced by oxidation glucose = e- released from redox rxn are carried on NADH
• SLP = substrate level phosphorylation = when energy for ATP synthesis comes from the dephosphorylation of a substrate
• at the end of glycolysis - glucose is converted into 2 molecules of pyruvate (3C)
• 2ATP produced -> 2 used and 4 produced = 2 ATP/Glucose

Question 6

Transition rxn and draw it out

Answer 6

• oxidation of pyruvic acid to Acetyl CoA when pyruvate enters the mitochondria in the presence of oxygen
• occurs across both the MOM and MIM into matrix
• catalyzed by PDH(pyruvate dehydrogenase)
• Pyruvate is oxidized = 1 CO2, and NADH produced