LEC Amino Acid Catabolism, Glucose Metabolism, Fatty Acid Biosynthesis

Question 1

The first step in amino acid catabolism

Answer 1

Removal of the a-amino group by transamination

Question 2

In the first step of amino acid catabolism, ____ is transferred to ____ to give ____ and _____

Answer 2

a-amino group; a-ketoglutarate; glutamate; a-ketoacid

Question 3

2 pathways followed by the breakdown of carbon skeletons in amino acid catabolism

Answer 3

Glucogenic amino acid
Ketogenic amino acid

Question 4

One whose carbon skeleton is degraded to pyruvate or oxaloacetate, both of which may then be converted into glucose

Answer 4

Glucogenic amino acid

Question 5

One whose carbon skeleton is degraded to acetyl-CoA or acetoacetyl-CoA, both of which may then be converted to ketone bodies

Answer 5

Ketogenic amino acid

Question 6

The principal storage form of energy for most organisms

Answer 6

Oxidation of FA in triacylglycerols

Question 7

T/F: the energy yield per gram of FA oxidized is less than that per gram of carbohydrate oxidized

Answer 7

F

Question 8

Catalyze hydrolysis of bonds between fatty acid and the rest of triacylglycerols

Answer 8

Lipases

Question 9

Catalyze hydrolysis of bonds between fatty acid and the rest of phosphoacylglycerols

Answer 9

Phospholipases

Question 10

Fatty acid oxidation begins with ____

Answer 10

Activation

Question 11

A ___ bond is formed between the ____ group of the FA and the ___ group of CoA-SH

Answer 11

Thioester; carboxyl; thiol

Question 12

T/F: the acyl-CoA crosses both the outer and inner mitochondrial membrane

Answer 12

F (only the outer)

Question 13

The acyl group is transferred to ___, carried across the inner mitochondrial membrane, and transferred to _____

Answer 13

Carnitine; mitochondrial CoA-SH

Question 14

Carnitine acyltransferase has specificity for acyl groups between ____ to ____ carbons long

Answer 14

14-18

Question 15

A series of reactions that cleaves carbon atoms two at a time from the carboxyl end of a fatty acid

Answer 15

B-oxidation

Question 16

Identify the reaction in B-oxidation of fatty acids: oxidation of the a,B carbon-carbon single bond to a carbon-carbon double bond

Answer 16

Reaction 1

Question 17

Identify the reaction in B-oxidation of fatty acids: hydration of the carbon-carbon double bond

Answer 17

Reaction 2

Question 18

Identify the reaction in B-oxidation of fatty acids: oxidation of the B-hydroxyl group to a carbonyl group

Answer 18

Reaction 3

Question 19

Identify the reaction in B-oxidation of fatty acids: cleavage of the carbon chain by a reverse Claisen reaction

Answer 19

Reaction 4

Question 20

___ cycles of oxidation of B-oxidation are required for the oxidation of Stearic acid to acetyl-CoA

Answer 20

8

Question 21

T/F: the energy released by the oxidation of acetyl-CoA formed by B-oxidation of FA can be used to produce ATP

Answer 21

T

Question 22

T/F: odd-numbered FA are frequently encountered compared to even-numbered FA

Answer 22

F

Question 23

T/F: since odd-numbered FA do not occur frequently, they do not undergo B-oxidation

Answer 23

F

Question 24

The last B-oxidation cycle of a fatty acid with an odd numbers of carbon gives ____

Answer 24

Propionyl-CoA

Question 25

FA with odd number of carbons produce ____ in the last step of the oxidation

Answer 25

Propionyl-CoA

Question 26

Propionyl-CoA can be converted to ___, which plays a role in the citric acid cycle

Answer 26

Succinyl-CoA

Question 27

T/F: The oxidation of unsaturated FA requires enzymes that catalyze isomerization around the double bonds

Answer 27

T

Question 28

Formation of ketone bodies occurs when the amount of acetyl-CoA produced is ___ compared to the amount of oxaloacetate

Answer 28

Excessive

Question 29

Bodily processes that leads to the formation of ketone bodies (3)

Answer 29

1. Intake high in lipids and low in carbohydrates 2. Diabetes not suitably controlled 3. Starvation

Question 30

Components of ketone bodies (3)

Answer 30

Acetone B-hydroxybutyrate Acetoacetate

Question 31

Ketone bodies are formed principally in ____

Answer 31

Liver mitochondria

Question 32

T/F: ketone bodies are used as a fuel to most tissues and organs

Answer 32

T

Question 33

What does the body produce if it has excess acetyl-CoA?

Answer 33

Ketone bodies

Question 34

Where does biosynthetic reactions occur?

Answer 34

Cytosol

Question 35

T/F: biosynthesis is the exact reversal of oxidation

Answer 35

F

Question 36

Enumerate the fatty acid biosynthesis

Answer 36

1. Ligation 2. Transfer 3. Transfer 4. Condensation 5. Reduction 6. Dehydration 7. Reduction

Question 37

What happens in the first step of fatty acid biosynthesis?

Answer 37

Ligation of Acetyl-CoA to malonyl-CoA

Question 38

What happens in the second step of fatty acid biosynthesis?

Answer 38

Transfer of Acetyl-CoA to acetyl-ACP

Question 39

What happens in the third step of fatty acid biosynthesis?

Answer 39

Transfer for malonyl-CoA to malonyl-ACP

Question 40

What happens in the fourth step of fatty acid biosynthesis?

Answer 40

Condensation of acetyl-S-K + malonyl-ACP to acetoacyl-ACP + K-SH

Question 41

What happens in the fifth step of fatty acid biosynthesis?

Answer 41

Reduction of acetoacyl-ACP to D-3-hydroxybutyryl-ACP

Question 42

What happens in the sixth step of fatty acid biosynthesis?

Answer 42

Dehydration of D-3-hydroxybutyryl-ACP to crotonyl-ACP

Question 43

What happens in the seventh step of fatty acid biosynthesis?

Answer 43

Reduction of crotonyl-ACP to butyryl-ACP

Question 44

Where does the carboxylation by acetyl-CoA occur?

Answer 44

Cytosol

Question 45

The carrier of the carboxyl group in fatty acid biosynthesis

Answer 45

Biotin

Question 46

The key intermediate produced during fatty acid biosynthesis

Answer 46

Malonyl-CoA

Question 47

In the initiation steps of fatty acid biosynthesis the acetyl group from acetyl-CoA is transferred to ____ through ____

Answer 47

Acyl carrier protein (ACP); acetyl tranferase

Question 48

The acetyl-ACP gets transferred to ____ in the initiation step of fatty acid biosynthesis

Answer 48

B-ketoacyl-S-ACP-synthetase

Question 49

Enumerate the "reverse" steps in fatty acid biosynthesis

Answer 49

1. Condensation of malonyl-ACP and acetyl-KSase form acetoacyl-ACP using acyl-malonyl enzyme 2. Reduction of acetacyl-ACP to D-B-hydroxybutyryl-ACP using B-ketoacyl-ACP reductase 3. Dehydration of D-B-hydroxybutyryl-ACP to Crotonyl-ACP using B-hydroxyacyl-ACP-dehydrase 4. Reduction of Crotonyl-ACP to Butyryl-ACP using 2,3-trans-enoyl-ACP reductase