Textbook Question
Compare and contrast substrate-level phosphorylation and oxidative phosphorylation.
1689
views
Ch. 9 - Cellular Respiration and Fermentation
Freeman7th EditionBiological ScienceISBN: 9783584863285
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 1 - Biology: The Study of Life11
- Ch. 2 - Water and Carbon: The Chemical Basis of Life10
- Ch.3 - Protein Structure and Function11
- Ch.4 - Nucleic Acids and the RNA World10
- Ch. 5 - An Introduction to Carbohydrates10
- Ch. 6 - Lipids, Membranes, and the First Cells10
- Ch. 7 - Inside the Cell10
- Ch. 8 - Energy and Enzymes: An Introduction to Metabolism10
- Ch. 9 - Cellular Respiration and Fermentation16
- Ch. 10 - Photosynthesis14
- Ch. 11 - Cell-Cell Interactions14
- Ch. 12 - The Cell Cycle12
- Ch. 13 - Meiosis13
- Ch. 14 - Mendel and the Gene32
- Ch. 15 - DNA and the Gene: Synthesis and Repair8
- Ch. 16 - How Genes Work35
- Ch. 17 - Transcription, RNA Processing, and Translation16
- Ch. 18 - Control of Gene Expression in Bacteria19
- Ch. 19 - Control of Gene Expression in Eukaryotes17
- Ch. 20 - The Molecular Revolution: Biotechnology, Genomics, and New Frontiers23
- Ch. 21 - Genes, Development, and Evolution13
- Ch. 22 - Evolution by Natural Selection17
- Ch. 23 - Evolutionary Processes13
- Ch. 24 - Speciation15
- Ch. 25 - Phylogenies and the History of Life13
- Ch. 26 - Bacteria and Archaea17
- Ch. 27 - Diversification of Eukaryotes19
- Ch. 28 - Green Algae and Land Plants18
- Ch. 29 - Fungi19
- Ch. 30 - An Introduction to Animals9
- Ch. 31 - Protostome Animals20
- Ch. 32 - Deuterostome Animals19
- Ch. 33 - Viruses16
- Ch. 34 - Plant Form and Function16
- Ch. 35 - Water and Sugar Transport in Plants16
- Ch. 36 - Plant Nutrition13
- Ch. 37 - Plant Sensory Systems, Signals, and Responses16
- Ch. 38 - Flowering Plant Reproduction and Development16
- Ch. 39 - Animal Form and Function16
- Ch. 40 - Water and Electrolyte Balance in Animals16
- Ch. 41 - Animal Nutrition16
- Ch. 42 - Gas Exchange and Circulation16
- Ch. 43 - Animal Nervous Systems16
- Ch. 44 - Animal Sensory Systems16
- Ch. 45 - Animal Movement11
- Ch. 46 - Chemical Signals in Animals16
- Ch. 47 - Animal Reproduction and Development18
- Ch. 48 - The Immune System in Animals16
- Ch. 49 - An Introduction to Ecology16
- Ch. 50 - Behavioral Ecology16
- Ch. 51 - Population Ecology16
- Ch. 52 - Community Ecology20
- Ch. 53 - Ecosystems and Global Ecology16
- Ch. 54 - Biodiversity and Conservation Ecology16
Chapter 9, Problem 7
In step 3 of the citric acid cycle, the enzyme isocitrate dehydrogenase is regulated by NADH. Compare and contrast the regulation of this enzyme with the regulation of phosphofructokinase in glycolysis.
Verified step by step guidance1
Identify the enzymes and pathways involved: Isocitrate dehydrogenase is an enzyme in the citric acid cycle, which is regulated by NADH. Phosphofructokinase is an enzyme in glycolysis, primarily regulated by ATP and AMP.
Understand the type of regulation: Isocitrate dehydrogenase is inhibited by high levels of NADH, indicating a feedback inhibition mechanism. This is because NADH is a product of the citric acid cycle, and its accumulation suggests that energy production needs to slow down.
Contrast with phosphofructokinase regulation: Phosphofructokinase is inhibited by ATP (high-energy molecule) and activated by AMP (low-energy molecule). This regulation is also a form of feedback inhibition but focuses on the energy status of the cell rather than the concentration of a specific product of the pathway.
Discuss the role of allosteric sites: Both enzymes are allosterically regulated, but the molecules that bind to these sites differ. Isocitrate dehydrogenase has allosteric sites for NADH, while phosphofructokinase has allosteric sites for ATP and AMP.
Examine the physiological implications: The regulation of these enzymes ensures that energy production is balanced according to the cell's needs. Isocitrate dehydrogenase slows the citric acid cycle during high-energy conditions (high NADH), while phosphofructokinase slows glycolysis during energy-rich conditions (high ATP) and speeds it up during energy-poor conditions (high AMP).
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Citric Acid Cycle
The citric acid cycle, also known as the Krebs cycle, is a series of enzymatic reactions that occur in the mitochondria, where acetyl-CoA is oxidized to produce energy in the form of ATP, NADH, and FADH2. It plays a crucial role in cellular respiration, linking carbohydrate, fat, and protein metabolism. Understanding this cycle is essential for analyzing the regulation of enzymes like isocitrate dehydrogenase.
Recommended video:
Guided course
02:45
Acids
Enzyme Regulation
Enzyme regulation refers to the mechanisms that control the activity of enzymes, ensuring metabolic pathways respond appropriately to the cell's needs. This can occur through various means, including allosteric regulation, covalent modification, and feedback inhibition. In the case of isocitrate dehydrogenase, its activity is inhibited by high levels of NADH, indicating sufficient energy supply, while phosphofructokinase in glycolysis is regulated by ATP and citrate, reflecting the energy status of the cell.
Recommended video:
Guided course
02:55Enzymes
Phosphofructokinase (PFK)
Phosphofructokinase (PFK) is a key regulatory enzyme in glycolysis that catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate. It is considered a major control point in the glycolytic pathway and is allosterically inhibited by ATP and citrate, signaling high energy levels, while activated by AMP, indicating low energy. Comparing its regulation with that of isocitrate dehydrogenase highlights different mechanisms of metabolic control in energy production.
Recommended video:
Guided course
08:57Feedback Regulation
Related Practice
Textbook Question
Compare and contrast substrate-level phosphorylation and oxidative phosphorylation.
2679
views
Textbook Question
If you were to expose cells that are undergoing aerobic respiration to a radioactive oxygen isotope in the form of O2, which of the following molecules would you expect to be radiolabeled?
a. Pyruvate
b. Water
c. NADH
d. CO2
1844
views
1
rank
Textbook Question
Explain the relationship between electron transport and oxidative phosphorylation. How do uncoupling proteins 'uncouple' this relationship in brown adipose tissue?
1150
views
Textbook Question
The researchers who observed that magnetite was produced by bacterial cultures from the deep subsurface carried out a follow-up experiment. These biologists treated some of the cultures with a drug that poisons the enzymes involved in electron transport chains. In cultures where the drug was present, no more magnetite was produced. Does this result support or undermine their hypothesis that the bacteria in the cultures perform cellular respiration? Explain your reasoning.
938
views
Textbook Question
Explain the relationship between electron transport and oxidative phosphorylation. How do uncoupling proteins 'uncouple' this relationship in brown adipose tissue?
1896
views