1. Harvesting Energy Topics you are not responsible for:
The individual enzymatic steps of glycolysis, Krebs cycle and the ETC
The details of fat metabolism through β-oxidation
Be able to answer questions:
Self-test #s 1,3,6-13
Harvesting Energy

2. Can dieting lengthen your life?
What is “calorie restriction” ?
Animal data – true for humans?
Why ???
Hormesis theory
Activation of “longevity genes”
Reduced “free radicals”
Free radicals are normal product of
cellular respiration
-- electron transport chain
-- H2O2, O2- ; OH-, etc
Harvesting Energy

3. Cellular Respiration lies at center of cellular metabolism
Produces:
energy supply
& intermediates
for other
pathways
Harvesting Energy

4. How are different foods ‘processed’ into usable cellular energy?
Catabolism
Anabolism
Ultimate
catabolic
products
Harvesting Energy

5. How is cellular respiration different from combustion?
How is it similar?
Harvesting Energy

6. What are the 2 mechanisms of producing ATP?
ADP + Pi  ATP
Substrate level ATP synthesis
-- glycolysis
-- Krebs cycle
Chemiosmotic ATP synthesis
-- electron transport
Harvesting Energy

7. What are the overall stages of cellular respiration?
Where do these processes occur?
Under what conditions do they occur?
Terminology usage
Cellular respiration vs
Aerobic respiration
Harvesting Energy

8. What are the principal chemical changes that occur during glycolysis?
Oxidation &
Priming Cleavage ATP synthesis
What is the energy
yield from glycolysis?
Harvesting Energy

9. What are some other coenzymes and prosthetic groups required for metabolism?
NADH
-- Vitamin B3 (Niacin)
-- How are electrons
stored in NADH?
FADH
-- need Vitamin B2 (Riboflavin)
Pyridoxal-phosphate
-- need Vitamin B6 (Pyrodoxin)
-- AA metabolism
Riboflavin
Pyridoxal-PO4
Harvesting Energy

10. Why is Arsenate poisonous?
AsO43- resembles and substitutes for PO43-
For example:
Normal glycolysis reaction:
3-Phosphoglycerate + PO4  1,3-bisphosphoglycerate
In presence of Arsenate
3-Phosphoglycerate + AsO4  1-arseno-3-phosphoglycerate
Harvesting Energy

11. What are the fate(s) of pyruvate?
What is the function
of fermentation?
-- Pyruvate disposal
-- NAD+ recycling
Harvesting Energy

12. What is the structure of Mitochondria?
Where do different reactions occur?
Harvesting Energy

13. How is Pyruvate converted into Acetyl-CoA?
Pyruvate dehydrogenase
-- Decarboxylation
What is Coenzyme-A?
Why is Acetyl-CoA important
in metabolism?
Harvesting Energy

14. Back to alcohol metabolism… What are the metabolic consequences on liver of alcoholism? (some of them!)
Weight loss
Arteriosclerosis  heart attacks
Acidosis  kidney damage
Liver cirrhosis
Consequences of
NADH/NAD imbalance
Harvesting Energy

15. What are the function and major events of the Krebs cycle?
What are the end products?
-- useful
-- waste
Harvesting Energy

16. How does the Electron Transport chain pass energy from NADH to ATP?
Loss of e- creates free radicals
Redox Potential of
NADH Q Cyt-c O2
Increasing affinity for e-
E- Transport Chain
ATP synthase
Hydrogen Ion Gradient
Harvesting Energy

17. How is heat production enhanced in brown adipose tissue (BAT)?
What is BAT? ...WAT?
“Nonshivering thermogenesis”
Involves “Uncoupling” of e- transport from ATP synthesis
-- Thermogin transporter
Under Thyroid hormone control
Relationship to weight control
Harvesting Energy

18. What is the net energy yield from glucose?
2.5 ATP / NADH
1.5 ATP / FADH
Prokaryotes vs
Eukaryotes
Total energy
yield = ~ 30%
Where did rest of
energy go?
Harvesting Energy