Log in
Biology
1
answer
0
watching
168
views

Under normal conditions, healthy heart cells (cardiac myocytes)prefer fatty acids as their fuel which ultimately results in energy being generated from oxidative phosphorylation through the electron transport chain. We will talk about how fatty acids are oxidatively metabolized in lecture 10. The condition ischemic cardiomyopathy is a result of narrowing of heart arteries which leads to decreased blood flow and a decrease in oxygen delivery to the muscle cells of the heart. In the ischemic heart, metabolism shifts from fatty acid oxidation to glucose metabolism via glycolysis to generate ATP and supply energy needs. a) Please explain why the ischemic heart shifts from energy generated by fatty acids to energy generated by glucose. b) In the ischemic heart, an increase in glycolysis is not associated with an increase in glycolytic enzyme expression. What is the general means by which the increase in glycolysis is mediated if it is not via an increase in enzyme expression? c) In ischemic cardiomyopathy, the decreased blood flow to the heart results in a decrease in blood glucose moving through hart arteries. Given that glycolysis is increased in the ischemic heart, discuss two potential ways that heart cells can acutely (in a rapid time period) increase glucose levels to supply the increased demand for glycolysis.

Watch
1
answer
0
watching
168
views

For unlimited access to Homework Help, a Homework+ subscription is required.

Patrina Schowalter
Patrina SchowalterLv2
28 Sep 2019

Unlock all answers

Get 1 free homework help answer.
Already have an account? Log in
Share

Related textbook solutions

Molecular Cell Biology
8 Edition,
Lodish
ISBN: 9781464183393
Biology: Science for Life with Physiology
6 Edition,
Belk
ISBN: 9780134555430
Biology
2nd Edition, 2013
Openstax
ISBN: 9781947172517
Concepts of Biology
OER Edition,
Openstax
ISBN: 9781938168116
Essentials of Biology
5 Edition,
Mader
ISBN: 9781259660269

Related questions

10- With respect to regulation of fatty acid metabolism chose the FALSE statement from those below?

a) ACC and FAS synthesis is stimulated by Insulin

b) ACC and FAS synthesis is stimulated by the well-fed state

c) Starvation leads to an increase in the synthesis of ACC and FAS.

d) Adipose tissue levels of lipoprotein lipase also are increased by insulin and decreased by starvation.

e) The long-term regulation of fat metabolism is achieved by alteration of the rate of enzyme synthesis and turn-over

14-With respect to the clinical significance of ketogenesis, which of the statements below are FALSE?

a) The Ketone bodies are relatively strong acids

b) The increase of ketone bodies in the blood lowers the pH of the blood.

c) The acidification of the blood by an increase of ketone bodies in the blood is dangerous because it impairs the ability of hemoglobin to bind oxygen

d) A severe increase of ketone bodies in the blood occurs in untreated insulin-dependent diabetes mellitus.

e) none of the above

15-With respect to ketogenesis, which statement below is FALSE?

a) Acetoacetate and b-hydroxybutyrate are major substrates for the biosynthesis of neonatal cerebral lipids.

b) In early stages of starvation, the heart and skeletal muscle consumes primarily ketone bodies to preserve glucose for use by the brain.

c) The fate of the products of fatty acid metabolism is determined by an individual's physiological status.

d) Ketogenesis takes place only in the liver.

e) all of the above

6. During fasting the liver pyruvate kinase enzyme is :

A. inhibited by phosphorylation by PKA

B. activated by phosphorylation by PKA

C. located in the mitochondria

D. activated by ATP

_______7. Phosphorylation of glycogen phosphorylase kinase by PKA in the liver:

A. activates of glycogen synthase

B. inactivates of glycogen synthase

C. inactivates of glycogen phosphorylase kinase

D. activates of glycogen phosphorylase kinase

_____8. In the skeletal muscle when a football player runs sprints during practice, the NADH produced in glycolysis at the glyceraldehydes 3-phosphate step is re-oxidized primarily by:

A. Malate dehydrogenase

B. Lactate dehydrogenase

C. Pyruvate dehydrogenase

D. Isocitrate dehydrogenase

_____9. Which of the following compounds is an allosteric activator of pyruvate carboxylase?

A. Biotin

B. Acetyl CoA

C. NADH

D. insulin

______10. Fatty acids with an odd number of carbon atoms and certain branched-chain fatty acids can support the net synthesis of glucose because they:

A. are converted to acetoacetate and β-hydroxybutyrate

B. are converted to malonyl-CoA

C. can produce propionyl-CoA which is converted to succinyl-CoA

D. Increase the NAD/NADH ratio

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.

Weekly leaderboard

Home
Homework Help 3,900,000
Biology 460,000
Start filling in the gaps now
Log in