Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

21. The Generation of Biochemical Energy

The Citric Acid Cycle

GOB Chemistry

21. The Generation of Biochemical Energy

The Citric Acid Cycle

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1:04 minutes

Problem 42b

Textbook Question

Refer to the diagram of the citric acid cycle in Figure 18.13 to answer each of the following:
b. What are the four-carbon compounds?

Verified step by step guidance

Step 1: Begin by understanding the citric acid cycle (also known as the Krebs cycle or TCA cycle). It is a series of chemical reactions used by all aerobic organisms to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins.

Step 2: Refer to Figure 18.13 of the citric acid cycle diagram. Identify the compounds involved in the cycle, paying close attention to the molecular structures and carbon counts of each compound.

Step 3: Focus on the compounds that have four carbon atoms. These are intermediates in the cycle and play a key role in the transfer of energy and electrons.

Step 4: Note that the four-carbon compounds in the citric acid cycle include oxaloacetate, succinate, fumarate, and malate. These compounds are involved in different steps of the cycle, such as regeneration of oxaloacetate and conversion of succinate to fumarate.

Step 5: Understand the role of these four-carbon compounds in the cycle. For example, oxaloacetate combines with acetyl-CoA to form citrate, and fumarate is formed during the oxidation of succinate. This helps in understanding the flow of carbon atoms and energy within the cycle.

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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 key metabolic pathway that takes place in the mitochondria. It involves a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. The cycle produces energy-rich molecules such as ATP, NADH, and FADH2, which are essential for cellular respiration.

Four-Carbon Compounds

In the context of the citric acid cycle, four-carbon compounds play a crucial role in the cycle's progression. Notable four-carbon intermediates include succinate and oxaloacetate. These compounds are involved in various steps of the cycle, facilitating the conversion of energy and the regeneration of the cycle's starting material, which is essential for continuous operation.

Metabolic Intermediates

Metabolic intermediates are the various compounds formed during the metabolic pathways, including the citric acid cycle. They serve as substrates for subsequent reactions and are vital for the regulation of metabolic processes. Understanding these intermediates, such as the four-carbon compounds, helps in grasping how energy is produced and utilized in cellular metabolism.