11-12. Cellular Respiration Flashcards
What does oxidative metabolism rely on?
Oxygen to breakdown fuels for energy
What does oxidative metabolism produce? Where?
ATP in the mitochondria of cells
In what way is oxidative metabolism better than anaerobic metabolism?
Yields more ATP
What is the primary method of energy production during endurance events (longer than 1 min)?
Oxidative metabolism
What are the stages of aerobic glycolysis?
- Glycolysis
- PDH rxn
- Krebs cycle
- Electron transport
Where does cellular respiration occur?
In mitochondria
What 2 metabolic pathways is cellular respiration an interaction between?
- Krebs cycle
- Electron transport chain
What are the primary goals of cellular respiration?
- Decarboxylation = formation of CO2
- NADH production
- ATP production
What are the primary goals of cellular respiration?
- Decarboxylation = formation of CO2
- NADH production
- ATP production
Describe the basic structure of the mitochondrion.
- Outer membrane = phospholipid bi-layer that contains porins (allow access of most ions and molecules to intermembrane space)
- Inner membrane = impermeable to most ions; maintains electrochemical gradient
- Cristae = folds that increase surface area
- Matrix = cytosol in center of mitochondria
Where are the enzymes of the krebs cycle found?
Matrix of mitochondria
Where does the krebs cycle occur?
Matrix of mitochondria
What is the primary function of the Krebs cycle?
Complete oxidation of CHOs, fats, or proteins using NAD or FAD as E- and H+ carriers
Where are mitochondria found w/in the muscle fiber?
Intermyofibrilar = in between filaments
What substance does entry into the Krebs Cycle require? Where can it come from?
Acetyl CoA from either CHOs, fat, protein
How do pyruvate and lactate gain entry into the mitochondria?
Via a carrier protein MCT located in the inner membrane
How do pyruvate and lactate gain entry into the mitochondria?
Via a carrier protein MCT located in the inner membrane
What is the major determinant of CHO oxidation during dynamic exercise?
Pyruvate dehydrogenase
How does pyruvate dehydrogenase compete with lactate dehydrogenase for pyruvate?
Depends on which route pyruvate takes after glycolysis –> aerobic or anaerobic
What is PDH actively regulated by?
Phosphorylation
During glycolysis, what are the control points of glucose uptake?
- GLUT 4
- Hexokinase?
During glycolysis, what are the control points of glucose breakdown?
- Phosphorylase
- Inorganic phosphate
What are the control points of rate of glycolysis?
- Phosphofructokinase
- Glucose 6 phosphate
During glycolysis, what os the control point of the regulation of pyruvate oxidation?
Pyruvate dehydrogenase
What enzyme controls the conversion of pyruvate into acetyl CoA?
Pyruvate dehydrogenase
Name the rate limiting enzyme of the Krebs Cycle? What controls it?
- Isocitrate dehydrogenase
- Inhibited by high levels of ATP and NADH
- Stimulated by high levels of ADP and inorganic phosphate, Ca2+ entering the mitochondria
Name the rate limiting enzyme of the Krebs Cycle? What controls it?
- Isocitrate dehydrogenase
- Inhibited by high levels of ATP and NADH
- Stimulated by high levels of ADP and inorganic phosphate, Ca2+ entering the mitochondria
During the Krebs cycle, one acetyl group is converted to:
- 2 CO2
- 3 NADH
- 1 FADH2
- 1 GTP converted to ATP
During the Krebs cycle, one acetyl group is converted to:
- 2 CO2
- 3 NADH
- 1 FADH2
- 1 GTP converted to ATP
Where does the electron transport system function in the mitochondrion?
Inner mitochondrial membrane
