L14: Fatty Acid and TG Metabolism

Question 1

Composition of fatty acids?

Answer 1

Hydrophobic tail
Hydrophilic head

Question 2

Glycerol + 3 fatty acids = ?

Answer 2

Triacylglycerol

Question 3

____ is the storage and transport form of amino acids

Answer 3

Triacylglycerol

Question 4

What bonds connect fatty acids to glycerol?

Answer 4

Ester bonds
(acid + OH)

Question 5

Which type of tissue stores triacylglycerol?

Answer 5

Adipose

Question 6

Saturated fatty acids lack a ___ in their tail while unsaturated have one

Answer 6

kink

Question 7

Example of saturated fatty acid? unsaturated?

Answer 7

saturated = butter
unsaturated = olive oil

Question 8

True or False: Saturated fatty acids are usually a liquid at room temperature whereas unsaturated fatty acids are usually solids at room temperature

Answer 8

False
saturated FA = solid
unsaturated FA = liquid

Question 9

Omega refers to location of ___ double bond, starting from end of FA tail

Answer 9

first

Question 10

What are the two essential fatty acids (cannot be made by diet, but be obtained via diet)

Answer 10

1) alpha-linoleic acid (omega-3-fatty acid)

2) linoleic acid (omega-6-fatty acid)

Question 11

Essential fatty acids are important for ___ signaling and function of ____

Answer 11

lipid; nervous system

Question 12

___: artificial creation of an unsaturated fatty acid that is SOLID at room temperature

Answer 12

Trans fat

Question 13

How does the double bond change in trans fats?

Answer 13

Double bond changed from cis to trans (makes tail more linear, similar to saturated fatty acid)

Question 14

Fatty acids are made at the ___ level and on a large scale in the ___ and ____

Answer 14

cellular; lactating mammary; liver

Question 15

When nutrient levels are high, intermediates will be transported ___ of the mitochondria and used to create ____ ____

Answer 15

out; fatty acids

Question 16

True or False: CoA can pass through the inner mitochondrial matrix

Answer 16

False - it cannot

Question 17

What are the types of CoA pools that exist?

Answer 17

1) Mitochondrial CoA pool
- cannot cross inner mitochondria membrane

2) Cytosolic CoA pool
- cannot EXIT mitpcondrial matrix

Question 18

Attaching CoA to a molecule will __ molecule from crossing inner mitochondrial membrane

Answer 18

prevent

Question 19

_____ is an enzyme involved in the first step of fatty acid synthesis.

What happens when it is inhibited?

Answer 19

Isocitrate dehydrogenase

• Citrate accumulation

Question 20

In the first step of fatty acid synthesis, high levels of ATP lead to?

Answer 20

Transport of citrate from mitochondrial to cytosol

Question 21

How does high ATP affect Isocitrate dehydrogenase in step 1 of fatty acid synthesis?

Answer 21

High ATP inhibits isocitrate dehydrogenase

Question 22

In the first stage of fatty acid synthesis, high levels of ATP leads to inhibition of ____, which leads to build up of ___ in the mitochondria and, eventually, its exported into the ___, where it continues to accumulate

Answer 22

isocitrate dehydrogenase;
citrate; cytosol

Question 23

Why is citrate able to leave the mitochondria in step 1 of fatty acid synthesis?

Answer 23

It is not bound to CoA

Question 24

Step 2 of fatty acid synthesis occurs in the ___.

Here, citrate is cleaved by which enzyme to reproduce oxaloacetate and acetyl CoA?

Answer 24

cytosl

ATP Citrate Lyase

Question 25

How does ATP Citrate Lyase add back CoA to the citrate molecule in step 2 of fatty acid synthesis?

Answer 25

Takes CoA from cytosolic pool

Question 26

In stage 3 of fatty acid synthesis, acetyl CoA is converted to ___ via which enzyme?

Answer 26

malonyl CoA

Acetyl-CoA-Carboxylase
- requires ATP and CO2

Question 27

What is the rate limiting, irreversible step of fatty acid synthesis?

Answer 27

Stage 3: Acetyl CoA to Malonyl CoA in the cytosol
(Acetyl-CoA-Carboxylase)

Question 28

Describe stage 4 of fatty acid synthesis?

Answer 28

Production of palmitate from malonyl-CoA

-Using malonyl CoA, Fatty Acid Synthase will take two of its carbons and incorporate them into growing fatty acid chain (1 C lost via CO2)

Question 29

Each malonyl-CoA unit incorporated increases fatty acids by _ carbons until _ carbons are reacher

Answer 29

2 carbons; 16 carbons (palmitate)

Question 30

___: the base fatty acid produced, can be modified into numerous other fatty acids; is saturated

Answer 30

Palmitate

Question 31

True or False: Palmitate is the end product of fatty acid synthesis

Answer 31

True

Question 32

True or False: fatty acid synthesis is a energy consuming process

Answer 32

True

Question 33

Polymerization of which enzyme allows for its activation?

Answer 33

ACC
Acetyl-CoA-Carboxylase

Question 34

What is the positive allosteric regulator for ACC?

Answer 34

Citrate

Question 35

Rising ____ inhibits polymerization of ACC subunits

Answer 35

palmitate (negative feedback)