Bio 21 Cell Biology
List of Terms and Study Guide 3
for MiniExam 2 on 3/7
Princliples of Bioenergetics
1st Law of Thermodynamics
2nd Law of Thermodynamics
free energy change
standard free energy change
Coupled reactions and Biosynthesis
overall free energy change
net standard free energy change
activated carrier molecules
3 stages of cell metabolism in breakdown of food molecules
macromolecules --> subunits
outside cell --> cytosol
subunits --> acetyl CoA
cytosol (--> mitochondria)
acetyl CoA --> CO2 and H2O
Glycolysis and Fermentation
(1) glucose --> (2) glyceradehyde 3-phosphate --> (2) pyruvate
-2ATPs + 4 ATPs = 2 ATPs net
NADH --> NAD+
ethanol + CO2
Citric Acid Cycle
Krebs cycle/tricarboxylic acid cycle
oxidation of pyruvate
major end products
CO2 and NADH
each turn of cycle: 3 NADH, 1 FADH2, 1 GTP (-->ATP)
one glucose => 2 pyruvate => 2 acetyl CoA
oxidation vs reduction
electron transport chain
mitochondrial inner membrane
plasma membrane of aerobic bacteria
2 NADH + 2 H+ + 1 O2 --> 2 H2O + 2 NAD+
10 H+ pumped per NADH molecule oxidized
3 H+ per ATP
1 H+ for ATP transport
You should be able to:
1. Explain, in your own words, the First and Second Law of Thermodynamics.
2. Distinguish between exergonic and endergonic reactions.
3. Describe the difference between free energy change (G) and standard free energy change (Go'), and how the ratio of reactants to products contributes to G. Be able to calculate G and determine whether or not an overall reaction will proceed spontaneously (given the appropriate data; e.g. G values for individual steps in a coupled reaction.)
4. Describe the function of ATP in the cell.
5. Describe the overall summary equation for cellular respiration.
6. Distinguish between substrate-level phosphorylation and oxidative phosphorylation.
7. Explain how exergonic oxidation of glucose is coupled to endergonic synthesis of ATP.
8. Define oxidation and reduction.
10. Explain how redox reactions are involved in energy exchanges.
11. Describe the role of ATP in coupled reactions.
12. Explain why ATP is required for the preparatory steps of glycolysis.
13. Write a summary equation for glycolysis and describe where it occurs in the cell.
14. Describe where pyruvate is oxidized to acetyl CoA, what molecules are produced and how it links glycolysis to the citric acid cycle.
15. Recognize the steps of the citric acid cycle and be able to describe what is happening in terms of "molecules in" and "molecules out".
16. Explain how the exergonic "fall" of electrons down the electron transport chain is coupled to the endergonic production of ATP by chemiosmosis.
17. Describe the process of chemiosmosis.
18. Explain how membrane structure is related to membrane function in chemiosmosis.
19. Summarize the net ATP yield from the oxidation of a glucose molecule by constructing an ATP ledger which includes electron carrier production (i.e., NADH, FADH2) during the different stages of glycolysis and cellular respiration.
20. Describe the fate of pyruvate in the absence of oxygen.
21. Explain why fermentation is necessary.
22. Distinguish between aerobic and anaerobic metabolism.
23. Describe evidence that the first prokaryotes produced ATP by glycolysis.