Energy Transfer Flashcards
(34 cards)
When glucose is broken down via glycolysis, how much ATP is produced?
2 ATP.
When broken down, how many kcals does ATP produce?
7.3 kcal/mol.
How much ATP does your body store, and how long can it sustain maximal exercise?
80-100g, 2-3 seconds.
What enzyme catalyzes the PCr reaction to create ATP?
Creatine phosphokinase.
What is the difference between oxidation and reduction?
In reduction reactions, electrons (H+) are being received.
In oxidation reactions, electrons (H+) are being given away.
Where is the ETC located, and what does it do?
It is located on the inner mitochondrial membrane.
In a ‘bucket brigade’ fashion, iron-protein electron carriers pass down electron pairs carried by NADH and FADH2. During this passage of electrons, energy is released to turn ADP into ATP.
What is the final electron acceptor?
Oxygen. It accepts hydrogen to make water.
How many molecules of ATP does NADH produce?
2.5.
How many molecules of ATP does FADH2 produce?
1.5.
What is the relative efficiency of oxidative phosphorylation?
It is 34% efficient.
What are the 3 pre-requisites for ATP re-synthesis during oxidative phosphorylation?
- availability of FADH and NADH in tissue.
- presence of o2 in tissue.
- sufficient content of mitochondrial enzymes.
How many moles of ATP does the complete breakdown of glucose yield?
32.
What are the 4 rate-limiting enzymes of glycolysis?
Hexokinase, phosphofructokinase, phosphorylase, pyruvate kinase.
What enzyme facilitates the formation of glycogen?
Glycogen synthase.
What 2 places in the body store glycogen?
Skeletal muscle and liver.
What enzyme facilitates glycogenolysis?
Glycogen phosphorylase.
When glycogen is broken down via glycolysis, how much ATP is produced?
3 mols ATP.
What happens when o2 is abundant (2 things)?
Glycolysis is inhibited.
Pyruvate enters the citric acid cycle and turns into acetyl-CoA irreversibly.
What happens to pyruvate when o2 is not available? What enzyme facilitates the reaction?
Pyruvate is reduced to form NAD+ and lactate. Lactate dehydrogenase (LDH) facilitates the reaction.
**This reaction is reversible.
How is lactate continually formed at rest/during moderate exercise?
- Via energy metabolism in RBC.
- In muscle fibers with high glycolytic activity.
How is lactate used in the body?
- Readily oxidized by neighboring muscle fibers, heart, and lung muscles.
- Acts as a substrate for glycogen synthesis (taken to the liver, Cori cycle).
How many kcal does complete oxidation of glucose yield?
686 kcal.
How much ATP does complete oxidation of a fat molecule yield?
460 ATP.
What are the 3 sources for fat catabolism?
- Triacylglycerols (TGs) stored in muscle mitochondria.
- Circulating TGs in lipoprotein complexes.
- Circulating free fatty acids mobilized from TGs in adipose tissue.
