TCA Cycle
The following enzyme types are not to be found in the TCA cycle:
What our notes say
- The following enzyme types are not to be found in the TCA cycle: (bchem EOY 2011 — Past Paper Questions & Answers)
- A true kinase (ATP/GTP-dependent phosphotransferase acting as classically named) is not part of the cycle, so B is the correct answer to "not found in the TCA cycle." (bchem EOY 2011 — Past Paper Questions & Answers)
- Tricarboxylic Acid Cycle (TCA/Krebs Cycle)Acetyl-CoA is oxidized in the TCA cycle:Produces NADH, FADH₂, and GTP/ATP. (Principles of Medical Microbiology and Parasitology LAQs & SAQs)
- Krebs Cycle (TCA Cycle):Pyruvate is converted to acetyl-CoA, which enters the TCA cycle, producing NADH and FADH₂. (Principles of Medical Microbiology and Parasitology LAQs & SAQs)
- NADPH can be converted into acetyl-coA which can undergo the TCA cycle or proceed to form ketone bodies for energy. (Medical Physiology Assorted SAQs — With Answers (Past Paper Study Guide))
- Glycolysis plus the TCA cycle can convert the carbons of glucose to , storing the energy as ATP, and . (Biochemistry Mid-Semester Exam — 2016 (Past Paper))
Study material on TCA Cycle
- Biochemistry Mid-Semester Exam — 2016 (Past Paper)
- bchem EOY 2011
- bchem EOY 2011 (2)
- CLINICAL BIOCHEMISTRY LAQs & SAQs
- Principles of Medical Microbiology and Parasitology LAQs & SAQs
- Biochemistry End of Year Exam — August 2011 (Past Paper)
- Biochemistry End of Year Exam — 2013 (Past Paper)
- Biochemistry Mid-Semester 2 CAT — 2013 (Past Paper)
Practice questions on TCA Cycle
Th . 89 ec and: carbon atoms from an odd-chain fatty acid will enter the TCA cycle as acetylCoA
- Citrate
- a-ketoglutarate
- SuccinylCoA ~
- Fumarate
- Oxaloacetate
Answer: A.
In the TCA cycle
- Three (3) of the enzymes are located in the inner mitochondrial membrane
- Enzyme-bound intermediates occur/exist
- Four (4) pairs of hydrogen atoms are produced in the form of NADH for each molecule of acetylCoA fed into the cycle
- Combined oxidation, dehydrogenation and decarboxylation reactions occur
- Addition of malonate inhibit the cycle --- Source: biochemistry/questions/bchem EOY 2012.pdf.
Answer: A.
The following enzymes(s) are **not** to be found in the TCA cycle ---
- Reversible
- Kinase(s)
- Hydrogenating
- Decarboxylating
- Phosphorylating
Answer: A.
The carbon skeletons of the following amino acids enter the TCA cycle via succinylCoA in humans ---
- Threonine
- Isolenine
- Asparagine
- Valine
- Methionine
Answer: A.
All the following amino acids can enter the TCA cycle as $\alpha$-ketoglutarate EXCEPT ---
- Glutamine
- Histidine
- Arginine
- Methionine
- Proline
Answer: A.
Out of the 24 ATPs formed in the TCA cycle, 2 ATPs are formed at substrate-level by the following reaction ---
- Citrate-Isocitrate
- $\text{Isocitrate} - \alpha\text{-ketoglutarate}$
- SuccinylCoA-Succinate
- Succinate – fumarate
- Malate – oxaloacetate
Answer: A.