BIOCHEM EXAM FINAL STUDY GUIDE 2026
QUESTIONS AND VERIFIED ANSWERS
Which of the following are components of animal fatty acid synthase (FAS)? Select all that
apply. - ANSWER--enoyl reductase
-3-hydroxyacyl dehydratase
-malonyl trasacylase
-Beta-ketoacyl synthase
Which of the following molecules regulate the enzyme that catalyzes malonyl-CoA synthesis? -
ANSWER--Citrate
- fatty acids or fatty acyl-CoA
Which of the following enzymes does malonyl-CoA regulate? - ANSWER-Carnitine
acyltransferase
True or False? For chloroplasts, the thylakoid membranes (lamellae) contain the enzymes
responsible for the carbon-fixation reactions. - ANSWER-False
What structure in chloroplasts contain the enzymes responsible for carbon-fixation reactions? -
ANSWER-The stroma
In photosystem II, P680 transfers an electron to pheophytin upon excitation by a photon. How is
this electron replaced? - ANSWER-by the splitting of water molecules at the manganese center
of the oxygen-evolving complex
In photosystem I, P700 transfers an electron to chlorophyll (A0) upon excitation by a photon.
How is this electron replaced? - ANSWER-by electrons transferred from plastocyanin
Paraquat acts by accepting electrons that would otherwise reduce ferredoxin, and it can accept
them from NADPH. The reduced form of paraquat then reacts with oxygen to form reactive
oxygen species (in this case, O2-), which damage chloroplast lipids and cause plant death. Which
of the following can you infer from this information? - ANSWER-Paraquat can interfere with the
formation or availability of NADPH.
Which of the following statements about the production of ATP in chloroplasts are true? Select
all that apply. - ANSWER--A proton gradient is generated by the transport of protons into the
thylakoid lumen.
-Protons move from the thylakoid lumen to the stroma through ATP synthase, producing ATP.
, Calculate the number of repetitions of the β-oxidation pathway required to fully convert a 16-
carbon activated fatty acid to acetyl-SCoA molecules. - ANSWER-7 repititions
Calculate the number of acetyl-SCoA molecules generated by complete β oxidation of a 16-
carbon activated fatty acid. - ANSWER-8 acetyl-SCoA
What is a symptom or effect of CPT 1 deficiency? - ANSWER-Long-chain fatty acids are not
transferred to carnitine
What is a symptom or effect of CPT 2 deficiency? - ANSWER-Acyl carnitine is not converted to
carnitine matrix
What is a symptom or effect of CACT deficiency? - ANSWER-Acyl carnitine is not transported
into mitochondrial matrix
The fourth reaction of the β-oxidation pathway is the thiolysis of a β-ketoacyl-CoA (3-ketoacyl-
CoA).
What is the product of this reaction? - ANSWER-Thiolase
What enzymes catalyze the thiolysis of a Beta-Ketoacyk-CoA? - ANSWER-Acetyl-CoA
Lauroyl-CoA
Characteristics of Fatty Acid Synthesis - ANSWER-1. begins with carboxylation of acetyl CoA
2. occurs in cytoplasm
3. enzymes are joined in a multienzyme complex
4. uses NADPH
5. committed step in formation of malonyl CoA
6. intermediates linked to acyl carrier protein
Characteristics of Fatty Acid Oxidation - ANSWER-1. Acetyl CoA is a product
2. Takes place in mitochondria
3. intermediates linked to coenzyme A
4. uses FAD and NAD+
Which of the statements about ACP and phosphopantetheine are true? - ANSWER-1.The
phosphopantetheine cofactor is bound to a Ser side chain of ACP.
2.The phosphopantetheine cofactor of ACP covalently binds intermediates of fatty acid synthase
reactions.
QUESTIONS AND VERIFIED ANSWERS
Which of the following are components of animal fatty acid synthase (FAS)? Select all that
apply. - ANSWER--enoyl reductase
-3-hydroxyacyl dehydratase
-malonyl trasacylase
-Beta-ketoacyl synthase
Which of the following molecules regulate the enzyme that catalyzes malonyl-CoA synthesis? -
ANSWER--Citrate
- fatty acids or fatty acyl-CoA
Which of the following enzymes does malonyl-CoA regulate? - ANSWER-Carnitine
acyltransferase
True or False? For chloroplasts, the thylakoid membranes (lamellae) contain the enzymes
responsible for the carbon-fixation reactions. - ANSWER-False
What structure in chloroplasts contain the enzymes responsible for carbon-fixation reactions? -
ANSWER-The stroma
In photosystem II, P680 transfers an electron to pheophytin upon excitation by a photon. How is
this electron replaced? - ANSWER-by the splitting of water molecules at the manganese center
of the oxygen-evolving complex
In photosystem I, P700 transfers an electron to chlorophyll (A0) upon excitation by a photon.
How is this electron replaced? - ANSWER-by electrons transferred from plastocyanin
Paraquat acts by accepting electrons that would otherwise reduce ferredoxin, and it can accept
them from NADPH. The reduced form of paraquat then reacts with oxygen to form reactive
oxygen species (in this case, O2-), which damage chloroplast lipids and cause plant death. Which
of the following can you infer from this information? - ANSWER-Paraquat can interfere with the
formation or availability of NADPH.
Which of the following statements about the production of ATP in chloroplasts are true? Select
all that apply. - ANSWER--A proton gradient is generated by the transport of protons into the
thylakoid lumen.
-Protons move from the thylakoid lumen to the stroma through ATP synthase, producing ATP.
, Calculate the number of repetitions of the β-oxidation pathway required to fully convert a 16-
carbon activated fatty acid to acetyl-SCoA molecules. - ANSWER-7 repititions
Calculate the number of acetyl-SCoA molecules generated by complete β oxidation of a 16-
carbon activated fatty acid. - ANSWER-8 acetyl-SCoA
What is a symptom or effect of CPT 1 deficiency? - ANSWER-Long-chain fatty acids are not
transferred to carnitine
What is a symptom or effect of CPT 2 deficiency? - ANSWER-Acyl carnitine is not converted to
carnitine matrix
What is a symptom or effect of CACT deficiency? - ANSWER-Acyl carnitine is not transported
into mitochondrial matrix
The fourth reaction of the β-oxidation pathway is the thiolysis of a β-ketoacyl-CoA (3-ketoacyl-
CoA).
What is the product of this reaction? - ANSWER-Thiolase
What enzymes catalyze the thiolysis of a Beta-Ketoacyk-CoA? - ANSWER-Acetyl-CoA
Lauroyl-CoA
Characteristics of Fatty Acid Synthesis - ANSWER-1. begins with carboxylation of acetyl CoA
2. occurs in cytoplasm
3. enzymes are joined in a multienzyme complex
4. uses NADPH
5. committed step in formation of malonyl CoA
6. intermediates linked to acyl carrier protein
Characteristics of Fatty Acid Oxidation - ANSWER-1. Acetyl CoA is a product
2. Takes place in mitochondria
3. intermediates linked to coenzyme A
4. uses FAD and NAD+
Which of the statements about ACP and phosphopantetheine are true? - ANSWER-1.The
phosphopantetheine cofactor is bound to a Ser side chain of ACP.
2.The phosphopantetheine cofactor of ACP covalently binds intermediates of fatty acid synthase
reactions.
