Fatty Acid Synthesis

Question 1

What is the main organ of fatty acid synthesis?

Answer 1

Liver

Question 2

What is the cellular location of fatty acid synthesis?

Answer 2

Cytosol

Question 3

Function of the malate citrate antiporter

Answer 3

Malate citrate antiporter moves acetyl CoA from mitochondria to cytoplasm

Question 4

Describe the function of the malic enzyme and name the coenzyme needed

Answer 4

Malate becomes pyruvate with coenzyme NADPH

Question 5

What is the reaction for Stage 1 of fatty acid synthesis?

Answer 5

Acetyl CoA + CO2 -> Malonyl CoA

Question 6

What is the name of the enzyme needed for Stage 1 of fatty acid synthesis? What coenzymes?

Answer 6

Acetyl CoA carboxylase with biotin and ATP

Question 7

What upregulates acetyl CoA carboxylase?

Answer 7

High carb/ low fat diet, insulin, citrate

Question 8

What down regulates acetyl CoA carboxylase?

Answer 8

High fat/ low carb diet, glucagon, epinephrine

Question 9

What is the overall reaction for Stage 2 of fatty acid synthesis?

Answer 9

8 Acetyl CoA + 7 malonyl CoA + 14 NADPH -> palmitate + 7CO2 + 7H2O

Question 10

What enzyme is used for Stage 2 of fatty acid synthesis?

Answer 10

Fatty acid synthase

Question 11

What is the end product of Stage 2 of fatty acid synthesis?

Answer 11

Palmitate, CO2, H2O

Question 12

malate citrate antiporter

Citrate becomes OAA + acetyl CoA using what enzyme?

Answer 12

ATP citrate lyase

Question 13

malate citrate antiporter

OAA becomes malate using what enzyme and coenzyme?

Answer 13

Malate dehydrogenase with NADH

Question 14

malate citrate antiporter

Malate becomes pyruvate using what enzyme and coenzyme?

Answer 14

Malic enzyme with NADPH

Question 15

malate citrate antiporter

Through a chain of reactions, citrate will become pyruvate which enters…

Answer 15

the mitochondria

Question 16

Describe the malate shuttle

Answer 16

Acetyl CoA from the mitochondria enters the cytoplasm via the malate-citrate antiporter

Question 17

Describe fatty acid synthase

Answer 17

7 distinct enzyme activities, dimer, arranged head to tail

Question 18

What upregulates fatty acid synthase?

Answer 18

High carb/ low fat diet

Question 19

What down regulates/ inhibits fatty acid synthase?

Answer 19

High levels of free fatty acids

Question 20

What is the name of the enzyme that converts palmitate to stearate?

Answer 20

Fatty acid elongase (with NADPH)

Question 21

What molecule is added in fatty acid elongation and synthesis of other fatty acids?

Answer 21

Malonyl CoA

Question 22

What coenzymes are needed for fatty acid elongation and synthesis of other fatty acids?

Answer 22

NADPH

Question 23

What is the process for creating short chain fatty acids?

Answer 23

Reverse of beta oxidation of fats in the mitochondria

Question 24

Where are very long chain fatty acids synthesized?

Answer 24

Brain

Question 25

What molecule is added for very long chain fatty acid synthesis?

Answer 25

Elongation of stearoyl CoA

Question 26

What are very long chain fatty acids used for?

Answer 26

Synthesis of sphingolipids during myelination

Question 27

Synthesis of TAGs in the liver consists of ___ being converted to ___ using enzyme ___

Answer 27

**glycerol** being converted to **glycerol 3P** using enzyme **glycerol kinase**

Question 28

Fatty acids are stored as ___

Answer 28

Triacylglycerol

Question 29

Synthesis of TAGs in adipose consists of ___ from ___ being converted to ___

Answer 29

**DHAP** from **glycolysis** being converted to **glycerol 3P**

Question 30

In TAG synthesis, glycerol 3P, using 2 acyl CoA, becomes ___, then ___

Answer 30

**phosphatidic acid**, then **diacylglycerol**

Question 31

In TAG synthesis, diacylglycerol becomes triacylglycerol using what enzyme?

Answer 31

Acyl CoA

Question 32

How are TAGs stored in the liver? How are they stored in adipose tissue?

Answer 32

Blood VLDL in liver Adipose stores in fat cells

Question 33

What are three factors that regulate total body fat?

Answer 33

1. Number and size of adipocytes 2. Genetically linked factors- dopamine receptors 3. Leptin

Question 34

Where is leptin made? What is its target?

Answer 34

Produced by white adipose tissue, targeting the hypothalamus

Question 35

What are three environmental factors that increase food intake and lead to increased body fat?

Answer 35

1. Eating a wide variety of food 2. Eating with more people 3. Availability of energy dense foods