Fatty Acid Metabolism German 9/27/16

Question 1

What are three sources to obtain lipids and fatty acids?

Answer 1

• Diet
• Adipose storage
• Synthesis in tissue

Question 2

What are the four fates of lipids and fatty acids?

Answer 2

• Energy substrates
• Precursors
• Structural elements
• Signaling Molecules

Question 3

What are dietary lipids processed and transported as?

Answer 3

Chylomicrons

Question 4

T/F Fatty acids are hydrophobic and stable in water

Answer 4

True

Question 5

What is the first step in processing dietary lipids?

Answer 5

-Bile salts emulsify fats in the small intestine forming mixed micelles

Question 6

In the second step of processing dietary lipids what brakes down triacylglycerols?

Answer 6

Intestinal lipases

Question 7

In the third step of processing and transporting the dietary lipids what takes up the fatty acids and break down products?

Answer 7

Intestinal mucosa

Question 8

In the third step of processing the dietary lipids are taken up by the intestinal mucosa and converted into what?

Answer 8

Triacylglycerols

Question 9

What happens in the fourth step of processing dietary lipids?

Answer 9

The Triacylglycerols are incorporated with cholesterol and apolipoproteins into chylomicrons

Question 10

In the fifth step of processing dietary lipids where do the chylomicrons move?

Answer 10

From the lymphatic system and bloodstream to the tissues

Question 11

While in the capillary what happens to the triacylglycerols found in the chylomicrons?

Answer 11

Lipoprotein lipase breaks them down to fatty acids and glycerols

Question 12

What are the three functions of apolipoproteins?

Answer 12

• Lipid binding proteins
• Combine with lipids to form lipoproteins
• Diverse functions

Question 13

What are the two ways that fatty acids are transported?

Answer 13

• Free Fatty acids

- Lipoproteins

Question 14

How are free fatty acids transported?

Answer 14

carried by serum albumin

Question 15

What is a phospholipid, cholesterol, and protein membrane-bound vesicles containing triglycerides?

Answer 15

Lipoproteins

Question 16

What are the four classes of lipoproteins?

Answer 16

• Chylomicrons
• Very Low Density Lipoprotein (VLDL)
• Low Density Lipoprotein (LDL)
• High Density Lipoprotein (HDL)

Question 17

Which type of lipoprotein has the highest amount of triacylglycerides in it?

Answer 17

chylomicrons

Question 18

Which type of lipoproteins has the lowest amount of triacylglycerides in it?

Answer 18

HDL

Question 19

What are the two major pathways of lipid transport?

Answer 19

• Exogenous

- Endogenous

Question 20

What type of lipoprotein is responsible for delivering fatty acids to target tissues?

Answer 20

VLDL

Question 21

What types of lipoproteins are responsible for transporting cholesterol?

Answer 21

• LDL

- HDL

Question 22

What is responsible for activating lipases?

Answer 22

Apolipoproteins

Question 23

What type of protein do you find in the exogenous pathway?

Answer 23

Chylomicrons

Question 24

What pathway do you find LDL, HDL, and VLDL?

Answer 24

Endogenous pathway

Question 25

T/F | Only 25% of the fatty acids transported are used by the tissues.

Answer 25

True

Question 26

Where is VLDL, HDL, and LDL synthesized?

Answer 26

Liver

Question 27

Where are LDL receptors synthesizes?

Answer 27

ER

Question 28

What is the first step of LDL entering the cell?

Answer 28

The LDL particle binds to the LDL receptor on the membrane

Question 29

What is the second step of LDL entering the cell?

Answer 29

LDL is internalized in and endosome

Question 30

What is the third step of LDL entering the cell?

Answer 30

-LDL receptors get recycled

Question 31

What is the fourth step of LDL entering the cell?

Answer 31

The LDL endosome fuses with a lysosome

Question 32

What is the fifth step of LDL entering the cell?

Answer 32

The lytic enzymes from the lysosome break down LDL particle

Question 33

What is the LDL particle broken down into?

Answer 33

- Amino Acids - Fatty Acids - Cholesterols (lipid droplet)

Question 34

When does the triacylglycerol cycle occur?

Answer 34

During starvation

Question 35

What are triacylglycerols broken down into in the triacylglycerol cycle?

Answer 35

- Glycerol | - Fatty acid

Question 36

What combines with a fatty acid in the liver to form a triacylgycerol?

Answer 36

Glycerol 3-phosphate

Question 37

What hormone initiates the release/breakdown of fatty acids?

Answer 37

Glucagon

Question 38

After glucagon has interacted with its receptor on the adipose tissue what does that eventually activate?

Answer 38

PKA

Question 39

What does PKA phosphorylate in the lipid droplet that creates an opening along the membrane?

Answer 39

Perilipin

Question 40

What breaks down the adipose triglycerides? (from triaclyglycerol to diacylglycerol)

Answer 40

ATGL (Adipose Triglyceride Lipase)

Question 41

What removes the glycerol linker in adipose triglycerides?

Answer 41

MGL (Monoglyceride lipase)

Question 42

Where does the glycerol that is released when the trigacylglycerides are broken down go for energy creation?

Answer 42

Glycolysis

Question 43

Where do the fatty acids from the triacylglycerides go for energy?

Answer 43

Form fatty acyl-CoAs used in Beta Oxidation

Question 44

Where are the fatty acyl-CoAs transported for oxidation?

Answer 44

Mitochondria

Question 45

What transports the fatty acyl-CoAs into the mitochondria?

Answer 45

Acyl-Carnitine/Carnitine Transporter

Question 46

What are the three stages that fatty oxidation occurs in?

Answer 46

- B-oxidation - CAC - Oxidative Phosphorylation

Question 47

What do you release per oxidation step in fatty acid B-Oxidation?

Answer 47

- 1 Acetyl CoA - 1 NADH - 1 FADH2

Question 48

How many carbons are reduced from the fatty acid per each step of the B-oxidation?

Answer 48

2 Carbons are removed

Question 49

What enzyme from B-oxidation feeds directly into the electron transport chain?

Answer 49

Acyl-CoA dehydrogenase

Question 50

Acetyl-CoA produced from B-oxidation enters two places what are they?

Answer 50

- CAC | - Forms Ketone bodies

Question 51

T/F Lipids can be a precursor for Amino Acid synthesis

Answer 51

True

Question 52

What are three important Ketone bodies produced from the Acetyl-CoA?

Answer 52

- Acetoacetate - Acetone - d-B-hydroxybutyrate

Question 53

What are ketones used as an energy source for?

Answer 53

- Heart - Skeletal muscle - Kidney - Brain

Question 54

Which two ketone bodies are exported as energy for the heart, skeletal muscle, kidney, and the brain?

Answer 54

- Acetoacetate | - D-B-Hydroxybutyrate

Question 55

T/F Acetone can be converted back to Acetyl CoA

Answer 55

False | It Can NOT

Question 56

How many carbons does palmitate have?

Answer 56

16

Question 57

T/F | Excess Acetyl-CoA can form fatty acids

Answer 57

True

Question 58

What hormone activates acetyl-CoA and Fatty acid synthesis?

Answer 58

Insulin

Question 59

What is the first step of fatty acid synthesis?

Answer 59

Transport of Acetyl-CoA into the cytoplasm

Question 60

What is the second step of fatty acid synthesis?

Answer 60

Carboxylation of acetyl-CoA into malonyl-CoA

Question 61

In the third step of fatty acid synthesis what enzyme combines acetyl-CoA and molonyl-CoA to start an acyl chain?

Answer 61

Fatty acid synthase

Question 62

In the fourth step of fatty acid synthesis what does fatty acid synthase do?

Answer 62

Adds Malonyl-CoA carbons to create palmitate

Question 63

Where are fatty acids modified?

Answer 63

In the ER

Question 64

What are four things that fatty acids can be modified into in the ER?

Answer 64

- Phospholipids - Sterols - FA elongation - FA desaturation

Question 65

Where does lipid synthesis occur?

Answer 65

Cytoplasmic space

Question 66

Where is acetyl-CoA produced?

Answer 66

Mitochondrial matrix

Question 67

How does acetyl-CoA get from the mitochondrial matrix to the cytoplasmic space?

Answer 67

Citrate Shuttle

Question 68

What enzyme is responsible for carboxylating acetyl-CoA to from malonyl-CoA?

Answer 68

Acetyl-CoA Carboxylase (ACC)

Question 69

What vitamin is necessary for ACC?

Answer 69

Biotin (vitamin b7)

Question 70

Why is malonyl-CoA necessary?

Answer 70

For acyl chain initiation and synthesis

Question 71

How many types of Fatty Acid synthase are there?

Answer 71

two

Question 72

Which type of fatty acid synthase is found in humans?

Answer 72

FAS I

Question 73

What is unique about FAS I?

Answer 73

It can only produce 16 carbon saturated fatty acids

Question 74

What are the two essential fatty acids?

Answer 74

Linoleate | A-Linolenate

Question 75

What is responsible for shuttling malonyl CoA to FAS?

Answer 75

Acyl Carrier Protein

Question 76

What is essential for the acyl carrier protein?

Answer 76

Pantothenic acid

Question 77

What are two ways that NADPH is produced?

Answer 77

- Pentose Phosphate Pathway | - Malic Enzyme

Question 78

T/F Insulin activates ACC via phosphatase that leads to fatty acid synthesis

Answer 78

True

Question 79

T/F ACC activity regulates the balance of FA synthesis and oxidation

Answer 79

True

Question 80

What inhibits the Fatty acyl-CoA from being converted into the fatty-acyl carnitine?

Answer 80

Malonyl-CoA

Question 81

What is required for FA synthesis to occur?

Answer 81

- 2 NADPH - 1 Acetyl CoA - 1 Malonyl CoA

Question 82

What two molecules help form phosphatidic acid?

Answer 82

- Glucose | - Glycerol

Question 83

T/F | FA addition to phosphatidic acid forms phospholipids and triglycerides

Answer 83

True

Question 84

T/F Cholesterol is not formed from acetyl-CoA

Answer 84

False | it is formed from acetyl CoA

Question 85

T/F Cholesterol is involved in lipoprotein and hormone formation

Answer 85

True

Question 86

If phosphatidic acid has a phosphate removed what does it become?

Answer 86

Triacylglycerol

Question 87

If phosphatidic acid has a phosphate group added what does it become?

Answer 87

Phospholipids

Question 88

What does HDL do?

Answer 88

Brings foam cells back to the liver

Question 89

What does a low level of HDL allow?

Answer 89

Plaque formation from foam cells