🏷️ LIMITED TIME OFFER: GET 20% OFF GRADE+ YEARLY SUBSCRIPTION →
Log in
HomeClass Notes1,200,000CA670,000

Biochemistry 2280A Lecture Notes - Lecture 15: Oxaloacetic Acid, Alpha-Ketoglutaric Acid, Cytosol

36 views5 pages
tealcockroach503
12 Dec 2016
School
Western University
Department
Biochemistry
Course
Biochemistry 2280A
Professor
Chris Brandl

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Topic 12 continued: one of the products of glycolysis is pyruvate. Under normal oxidative conditions pyruvate goes on to be oxidized in the mitochondrion (topic 13) When oxygen is absent, we need some way to regenerate nad+ so glycolysis can continue = fermentation: fermentation. Glycolysis consumes nad+ converts glucose to pyruvate nad+ must be regenerated. Fermentation: pathway that produces atp with no net oxidation of carbon. Electrically neutral there"s no electron input or output, but we"re still making atp. When o2 is present, this is done by the electron transport chain (topic 14) When o2 is absent, other reactions regenerate nad: strategy 1: formation of lactate. Glucose pyruvate reduced to lactate while nadh oxidized to nad+ This nad+ goes back into glycolysis and fuels that reaction. Net reaction: glucose + 2 adp + 2 pi 2 lactate + 2 atp: strategy 2: formation of ethanol.

Get access

Grade+20% off
$8 USD/m$10 USD/m
Billed $96 USD annually
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
40 Verified Answers
Class+
$8 USD/m
Billed $96 USD annually
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
30 Verified Answers

Related Documents

Biochemistry 2280A Lecture Notes - Pentose Phosphate Pathway, Glycogen Synthase, Allosteric Regulation
goldmole494
Biochemistry 2280A Lecture Notes - Lecture 10: Acetyl-Coa, Mitochondrial Matrix, Extrachromosomal Dna
mauveserval406
Biochemistry 2280A Lecture Notes - Lecture 17: Atp Synthase, Atp Hydrolysis, Electrochemical Gradient
tealcockroach503

Related Questions

1. Which of the following is common to both aerobic and anaerobicmicrobes?
Fermentation
An electron transport chain
Pyruvate oxidation
Glycolysis
All of the above
2. The primary purpose of catabolism is
generation of ADP.
generation of ATP.

oxidation of NADH to NAD+.
degradation of organic molecules.
biosynthesis.
3. What is a fate of pyruvate during alcoholic fermentation byyeast?
It is reduced to lactic acid.
It is oxidized to form glucose and carbon dioxide
It is cleaved to form acetylaldehyde and carbon dioxide.
It is catabolized in glycolysis.
It is oxidized to form lactic acid and carbon dioxide.
4. Electrons needed to reduce an oxidized electron acceptor areprovided by
a) externally provided compounds such asH<sub>2</sub>, lactate or formate.
b) an intermediate electron carrier such as NADH.
c) 0<sub>2</sub>.
d) Both a and b
e) All of the above
5. How are aerobic respiration and anaerobic respirationsimilar?
Both use oxygen as a terminal electron carrier.
These are other names for glycolysis.
Both utilize inorganic molecules as terminal electronacceptors.
Neither receives electrons from glycolysis.
Anaerobic respiration does not exist in microbes.
6. The conversion of phosphoenolpyruvic acid (PEP) topyruvate
a) releases CO<sub>2</sub>.
b) involves the conversion of ADP and ATP.
c) involves substrate-level phosphorylation.
d) Both a and b
e) Both b and c
7. Which of the following is the best definition offermentation?
The reduction of glucose to pyruvic acid

The complete catabolism of glucose to CO2 andH2O
The oxidation of a carbohydrate with organic molecules servingas electron donors and acceptors
The production of ATP from glucose
The production of ethanol from glucose
8. A reaction that yields energy has a
positive ?Go?.
negative ?Go?.
positive ?Eo?.
negative ?Eo?.
negative ?Ho?.
9. Oxidation and reduction reactions are always coupledbecause
a) electrons generally accompany protons.
b) protons generally accompany protons.
c) electrons cannot exist free in solution.
d) Both a and b
e) All of the above
10. Which of the following is true of aerobic respiration?
It involves the reduction of oxygen.
It involves the oxidation of oxygen.
It involves the reduction of lactic acid.
It involves the oxidation of lactic acid.
It does not generate ATP.

1. Plants need which of the following to carry on photosynthesis?

a. H2O

b. CO2

c. O2

d. both O2 and CO2

e. both H2O and CO2

2. Organisms that derive their chemical energy either from the process of chemosynthesis or photosynthesis are classified as

a. autotrophs.

b. parasites.

c. heterotrophs.

d. saprophytes.

e. mutualists.

3. The carbon source for organisms that derive their energy from photosynthesis is

a. carbon monoxide.

b. carbon dioxide.

c. hydrocarbons.

d. methane.

e. glucose.

4. The oxygen released in photosynthesis comes from

a. carbon dioxide.

b. glucose.

c. ribulose bisphosphate.

d. water.

5. When chlorophyll a molecules absorb energy, the molecules

a. release electrons.

b. release X-rays.

c. release energy.

d. release electrons and X-rays.

e. release electrons and energy.

6. The flow of what particle across the thylakoid membrane powers the production of ATP?

a. electrons

b. hydrogen ions

c. oxygen

d. carbon dioxide

e. phosphate ions 2

7. The light-independent reactions were discovered by

a. M. D. Hatch.

b. Andrew Benson.

c. Melvin Calvin.

d. Robert Hill.

e. both Andrew Benson and Melvin Calvin.

8. For each six atoms of carbon dioxide fixed in the light-independent reactions, how many molecules of PGAL (phosphoglyceraldehyde) are produced?

a. 2

b. 3

c. 6

d. 12

e. 15

Chapter 7

9. The ultimate source of energy for living things is

a. the Krebs cycle.

b. fossil fuels.

c. the sun.

d. glycolysis.

e. aerobic respiration.

10. When molecules are broken apart in respiration

a. the heat produced is used to drive biological reactions.

b. the oxygen in the compounds that are broken apart is used as an energy source.

c. the energy released in respiration is channeled into molecules of ATP.

d. ATP is converted into ADP.

e. ADP is released as a waste product.

11. ATP

a. can be produced by photosynthesis.

b. is produced in the degradation of organic compounds such as glucose.

c. is generated in anaerobic respiration.

d. is released in aerobic respiration.

e. all of these

12. Which part of the energy-releasing pathway can convert all carbon that enters to carbon dioxide?

a. fermentation

b. glycolysis

c. Krebs cycle

d. electron transport

e. phosphorylation

13. Which liberates the most energy in the form of ATP?

a. aerobic respiration

b. anaerobic respiration

c. alcoholic fermentation

d. lactate fermentation

e. All liberate the same amount, but through different means.

14. Aerobes use ________ as the final electron acceptor in electron transport phosphorylation.

a. hydrogen

b. carbon

c. oxygen

d. H2O 3

15. Glycolysis depends on a continuous supply of

a. NADP.

b. pyruvate.

c. NAD+.

d. NADH.

e. H2O.

16. Glycolysis

a. occurs in the mitochondria.

b. results in the production of pyruvate.

c. occurs in the cytoplasm.

d. occurs in the mitochondria and results in the production of pyruvate.

e. results in the production of pyruvate and occurs in the cytoplasm.

17. The end product(s) of glycolysis is(are)

a. acetyl CoA.

b. carbon dioxide.

c. pyruvate.

d. glucose.

e. glucose and carbon dioxide.

18. Which is capable of being reduced during both glycolysis and the Krebs cycle?

a. NAD+

b. FAD+

c. ADP

d. NADH

e. NADP+

19. The Krebs cycle takes place in the

a. ribosomes.

b. cytoplasm.

c. nucleus.

d. mitochondria.

e. chloroplasts.

20. The breakdown of pyruvate in the Krebs cycle results in the release of

a. energy.

b. carbon dioxide.

c. oxygen.

d. energy and oxygen.

e. energy and carbon dioxide.

1. C6H12O6 + 6O2 Ã 6CO2 + 6H2O Glucose is being _____ to _____ and oxygen is being _____ to _____. a. oxidized; carbon dioxide; reduced; water b. oxidized; water; reduced; carbon dioxide Incorrect c. reduced; water; oxidized; carbon dioxide d. reduced; carbon dioxide; oxidized; water

2. Which of the following stages in the breakdown of the piece of toast you had for breakfast generates the most ATP? a. the citric acid cycle Incorrect b. glycolysis c. the digestion of starch to glucose d. oxidative phosphorylation

3. Which of the following is a catabolic pathway? a. gluconeogenesis b. production of starch Incorrect c. glycolysis d. production of glycogen

4. Per molecule, the oxidation of a fatty acid results in _____ energy storage than the oxidation of glucose. a. the same b. less Incorrect c. more d. None of the above; fatty acids cannot be oxidized.

5. Of the eight reactions in the citric acid cycle, how many are oxidation-reduction reactions? a. one b. two c. three d. four e. five

6. The process of glycolysis transfers the energy in sugar molecules into the stored energy of activated carriers such as ATP and NADH. Which statement is true about glycolysis? a. Only eukaryotic organisms do glycolysis. b. The ten reactions of glycolysis are identical in all eukaryotic cells, but are different in prokaryotic cells due to their diverse metabolic strategies. Incorrect c. The ten reactions of glycolysis are identical in almost all living organisms on the planet. d. There are many ways to oxidize glucose and transfer energy into activated carriers; the diversity of organisms on the planet is reflected in the diversity of their mechanisms of glycolysis.

7. Referring to the sentence completed in #13 above, the purpose of the latter reaction (in active muscle cells) is to _____. a. accumulate lactic acid in the cell, which provides additional energy for the production of ATP Incorrect b. slow down glycolysis until oxygen becomes available again c. accelerate the Krebs cycle, which will restore the oxygen supply d. regenerate NAD+ so that glycolysis can continue in the absence of oxygen

8. What are the products of the citric acid cycle? a. carbon dioxide, NADH, FADH2 and GTP b. carbon dioxide, NAD+, FAD and GTP c. NADH, FADH2, and acetyl CoA Incorrect d. carbon dioxide and water

9. Which statement is true about enzymes? a. Enzymes catalyze chemical reactions because they make inherently endergonic reactions exergonic. b. Each enzyme in a cell can catalyze many different chemical reactions involving chemically different substrates. Incorrect c. Enzymes can only catalyze reactions in one direction. d. After catalyzing a reaction, an enzyme is permanently altered and can no longer bind substrate. e. None of the above is true. 1

10. ∆G measures the change in free energy in a system as it converts reactant (Y) into product (X). When [X] = [Y], ∆G is equal to _____. a. RT b. ΔG° + RT c. ΔG° d. ln [X]/[Y]

11. The ∆G° for the hydrolysis of ATP is -7.3 kcal/mol. What conditions in the cell would lead to a ∆G for ATP hydrolysis of -11 kcal/mol? a. An increase in the ATP/ADP ratio b. An increase in anabolic activity in the cell c. Transport of ATP out of the compartment where the reaction is occurring Incorrect d. A decrease in the ATP/ADP ratio

12. In the first reaction of glycolysis, a phosphate transferred from ATP to a glucose molecule to produce glucose-6-phosphate and ADP. Under conditions existing in the cell, the free energy change for this reaction is -8.0 kcal/mole. Which of the following statements is true? Recall that the ∆G° for the hydrolysis of ATP is -7.3 kcal/mol. a. Glucose concentrations in the cell are always low, making this reaction more favorable than would be expected. b. This reaction is less favorable than would be expected, given the ∆G° of ATP hydrolysis. c. Glucose-6-P concentrations in the cell are very low relative to glucose concentrations, making the reaction more favorable than would be expected. d. The ∆G° for the addition of a phosphate to glucose must be -0.7 kcal/mole.

13. Protein E can bind to two different proteins, S and I. The binding reactions are described by the following equations and values: E + S --> ES Keq for ES = 10 E + I> EI Keq for EI = 2 Given the equilibrium constant values, which one of the following statements is true? a. When S is present in excess, no I molecules will bind to E. b. E binds I more tightly than S. c. The binding energy of the ES interaction is greater than that of the EI interaction. d. Changing an amino acid on the binding surface of I from a basic amino acid to an acidic one will probably make the free energy of association with E more negative.