LECOM BIOCHEMISTRY EXAM 2
QUESTIONS AND ANSWERS
BIOCHEMISTRY 19: FATTY ACID METABOLISM - Correct Answers -BIOCHEMISTRY
19: FATTY ACID METABOLISM
Major Source of fuel overall - Correct Answers -fatty acids
Fatty acids come from - Correct Answers -diet (chylomicron)
liver (vldl)
adipose tissue reservoir
Most fatty acid oxidation occurs in what tissues - Correct Answers -muscle and liver
Fatty acids are oxidized in the - Correct Answers -mitochondria (mostly)
Fatty acid uses - Correct Answers -energy, storage, membrane
Short/ medium chain fatty acid absorption - Correct Answers -Absorb directly and
diffuse into the mitochondria
Long chain and very long chain fatty acid absorption - Correct Answers -Absorbed as
micelles (w/ADEK) and transported to the mitochondria with the help of carnitine
First step in fatty acid oxidation - Correct Answers -Activation via FA CoA synthetase-
adds an Acetyl CoA, uses ATP
Carnitine - Correct Answers -Absorbed from diet or made from lysine
Transport of long chain fatty acids into the mitochondria - Correct Answers -
, Beta Oxidation - Correct Answers -Activation (-1 ATP)
Oxidation (+1 FADH2)
Hydration (breaks the double bond)
Oxidation (+1 NADH)
Thiolysis (cleavage)
Activation - Correct Answers -Enzyme- Fatty Acid CoA Synthetase
Substrate- long chain fatty acids
Product- Fatty acyl CoA
-1 ATP
Beta Oxidation Enzymes - Correct Answers -1. Activation- Fatty Acyl CoA synthetase
2. Oxidation- Fatty Acyl CoA Dehydrogenase
3. Hydration- Enoyl Hydratase
4. Oxidation- Beta-OH Acyl CoA dehydrogenase
5. Thiolysis- Acyl CoA Acetyltransferase
Beta Oxidation of Palmitate (16C) - Correct Answers -7 turns of beta oxidation
7 FADH2 (1.5 ATP)
7 NADH (2.5 ATP)
8 Acetyl CoA (10 ATP)
Priming (-2 ATP)
Beta oxidation of odd chain fatty acids - Correct Answers -Last cleavage yields
Propionyl CoA, metabolized to succinyl CoA to enter the TCA cycle
Activation of beta oxidation - Correct Answers -Starvation and in general a low-energy
level
Low insulin and high glucagon (i.e. low insulin:glucagon ratio)
ADP
AMP
Inhibition of beta oxidation - Correct Answers -Fed state and high energy level
Malonyl CoA
High ATP:ADP
High Insulin
Low Glucagon
NADH
FADH2
Acetyl CoA Carboxylase (ACC) - Correct Answers -Acetyl CoA -->Malonyl CoA
ACC is activated by insulin
ACC is inhibited by AMP-PK (muscle, liver)
QUESTIONS AND ANSWERS
BIOCHEMISTRY 19: FATTY ACID METABOLISM - Correct Answers -BIOCHEMISTRY
19: FATTY ACID METABOLISM
Major Source of fuel overall - Correct Answers -fatty acids
Fatty acids come from - Correct Answers -diet (chylomicron)
liver (vldl)
adipose tissue reservoir
Most fatty acid oxidation occurs in what tissues - Correct Answers -muscle and liver
Fatty acids are oxidized in the - Correct Answers -mitochondria (mostly)
Fatty acid uses - Correct Answers -energy, storage, membrane
Short/ medium chain fatty acid absorption - Correct Answers -Absorb directly and
diffuse into the mitochondria
Long chain and very long chain fatty acid absorption - Correct Answers -Absorbed as
micelles (w/ADEK) and transported to the mitochondria with the help of carnitine
First step in fatty acid oxidation - Correct Answers -Activation via FA CoA synthetase-
adds an Acetyl CoA, uses ATP
Carnitine - Correct Answers -Absorbed from diet or made from lysine
Transport of long chain fatty acids into the mitochondria - Correct Answers -
, Beta Oxidation - Correct Answers -Activation (-1 ATP)
Oxidation (+1 FADH2)
Hydration (breaks the double bond)
Oxidation (+1 NADH)
Thiolysis (cleavage)
Activation - Correct Answers -Enzyme- Fatty Acid CoA Synthetase
Substrate- long chain fatty acids
Product- Fatty acyl CoA
-1 ATP
Beta Oxidation Enzymes - Correct Answers -1. Activation- Fatty Acyl CoA synthetase
2. Oxidation- Fatty Acyl CoA Dehydrogenase
3. Hydration- Enoyl Hydratase
4. Oxidation- Beta-OH Acyl CoA dehydrogenase
5. Thiolysis- Acyl CoA Acetyltransferase
Beta Oxidation of Palmitate (16C) - Correct Answers -7 turns of beta oxidation
7 FADH2 (1.5 ATP)
7 NADH (2.5 ATP)
8 Acetyl CoA (10 ATP)
Priming (-2 ATP)
Beta oxidation of odd chain fatty acids - Correct Answers -Last cleavage yields
Propionyl CoA, metabolized to succinyl CoA to enter the TCA cycle
Activation of beta oxidation - Correct Answers -Starvation and in general a low-energy
level
Low insulin and high glucagon (i.e. low insulin:glucagon ratio)
ADP
AMP
Inhibition of beta oxidation - Correct Answers -Fed state and high energy level
Malonyl CoA
High ATP:ADP
High Insulin
Low Glucagon
NADH
FADH2
Acetyl CoA Carboxylase (ACC) - Correct Answers -Acetyl CoA -->Malonyl CoA
ACC is activated by insulin
ACC is inhibited by AMP-PK (muscle, liver)
