lecture 3 lipid metabolism

Question 1

Adipose tissue as an _____ and _____ organ

Answer 1

endocrine and secretory

Question 2

There were two things that Dr. Williams underlined that adipocytes contribute to

Answer 2

Leptin, adiponectin, Resisting
-molecules regulating energy homeostasis

Molecules regulating innate immune system
-TNF a and IL-6

Question 3

Fatty acids are taken up by ____, where they may serve as precursors in the synthesis

Answer 3

cells

Question 4

after fatty acids are taken up by the cell, what are the different paths it can go

Answer 4

synthesis fatty acids for storage or export

mitochondria for energy or ketone bodies (export energy)

Question 5

What is the major form of energy storage?

Answer 5

fat

Question 6

what is the distribution fuel reserves in a typical individual

Answer 6

Fat: 100,000 kcal
Protein: 25,000 kcal
carbohydrate: 650 kcal

Question 7

What are the intermediated if fatty acid metabolism

Answer 7

phospholipid (in membranes)

Eicosanoids, including prostaglandins and leukotrienes which play a role in physiological regulation

Question 8

What are the diseases for fatty acid metabolism?

Answer 8

Diabetes mellitus
specific disorders of fatty acids oxidation like SIDS, Reye syndrome which might be related to a deficiency of medium chain acyl CoA, dehydrogenase, an important enzyme of fatty acid oxidation

Question 9

For SIDS AND Reye syndrome, what might that be related to

Answer 9

related to a deficiency of medium chain acyl CoA, dehydrogenase, an important enzyme of fatty acid oxidation

Question 10

What are two precursors of acetyl coA?

Answer 10

amino acids and glucose

Question 11

Acetyl coA makes what?

Answer 11

Fatty acids
triglycerides
phospholipid
eicosanoids
CO2, H2O,ATP
Cholesterol–> steroid hormones
Ketone bodies

Question 12

What is the structure of acetyl coA

Answer 12

1.Acetyl group
2.Coenzyme A
-Beta-mercaptoethylamine
-Pantothenic acid (not synthesized in man – an essential nutrient)
-Phosphate
-3’, 5’-adenosine diphosphate

Question 13

What is the structure of fatty acid

Answer 13

A long hydrocarbon chain
A carboxylic acid group

Question 14

What is the chain length and structure of fatty acids

Answer 14

Ranges from 4 to 30 carbons
Most common: 12-24 carbons
LINEAR
EVEN NUMBER OF CARBONS

Question 15

What is one system of fatty acid classification

Answer 15

based on the number of double bonds

Question 16

How many db are in saturated fatty acids

Answer 16

ZERO

Question 17

What is an example of saturated fatty acid

Answer 17

Stearic acid

Question 18

How many bonds are in monounsaturated fatty acids

Answer 18

ONE

Question 19

what is an example of monounsaturated fatty acid

Answer 19

oleic acid

Question 20

What does db in fatty acids cause and what is the result

Answer 20

db cause steric hinderance which affects the melting point

More dbs = lower melting point

Question 21

The db in natural unsaturated fatty acids are in ____ configuration

Answer 21

CIS

Question 22

Fatty acids with ____ double bond are the most prevalent in the human body

Answer 22

one

Question 23

in saturated fatty acids, why is the melting point higher?

Answer 23

Hydrophobic interaction with packed tightly

Solid

Question 24

More double bonds=

Answer 24

lower melting point

Question 25

LISTEN TO LECTURE TO ADD QUESTION

Question 26

What are the five common fatty acids that we need to remember

Answer 26

palmitic acid stearic acid oleic acid linoleic acid linolenic acid

Question 27

For the five common fatty acids, list them with their carboxyl reference

Answer 27

palmitic acid---> 16:0 stearic acid--->18:0 oleic acid ---> 18:1▵ 9 linoleic acid--> 18:2 ▵9, 12 linolenic acid--> 18:3 ▵9,12,15

Question 28

The first carbon numbers in the fatty acid is what?

Answer 28

The carboxyl carbon will always be one

Question 29

What is the carbon next to the the carboxyl carbon

Answer 29

alpha, then it goes to beta, gamma

Question 30

What is ALWAYS the last carbon, regardless of how many carbons we have

Answer 30

omega, ⍵

Question 31

Instead of starting with the carboxyl carbon for greek letters, what is the other way?

Answer 31

omega (⍵) subtracted by the number of carbons until we hit the db Example: ⍵-3--> the db is 3 carbons from the end

Question 32

Where does fatty acid synthesis occurs primarily in ?

Answer 32

CYTOPLASM of these tissues: -liver -adipose (fat) -central nervous system -lactating mammary gland

Question 33

What are the major lipogenic tissues?

Answer 33

liver adipose CNS lactating mammary gland

Question 34

What is the starting molecule of the de novo synthesis of fatty acids

Answer 34

glucose to pyruvate to then make acetyl coA

Question 35

What is the fatty acid created with the De Novo synthesis

Answer 35

palmitate (16:0)

Question 36

What is the process of glucose

Answer 36

Glucose is degraded to pyruvate by aerobic glycolysis in the cytoplasm. Pyruvate is transported into mitochondria, where pyruvate dehydrogenase oxidatively decarboxylates pyruvate, forming acetyl CoA which can serve as a substrate for citrate synthesis. Citrate transported out of the mitochondria to the cytoplasm (where fatty acid synthesis occurs), and split to generate acetyl CoA for fatty acid synthesis.

Question 37

what is another pathway that citrate can take besides fatty acid synthesis?

Answer 37

Citrate can be oxidized by TCA cycle in mitochondria to get energy

Question 38

What is the next step with acetyl CoA in fatty acid synthesis

Answer 38

Acetyl CoA + bicarbonate+ ATP with acetyl CoA carboxylase (biotin) to create malonyl CoA

Question 39

What is the RLS for de novo synthesis in fatty acid synthesis?

Answer 39

acetyl CoA carboxylase (biotin)

Question 40

What are the short term ways of regulating acetyl coA carboxylase?

Answer 40

Phosphorylation (inactive) -mediated by AMP-dependent protein -kinase and protein kinase A Dephosphorylation (active) -mediated by phosphoprotein phosphatase Allosteric regulation -citrate is a positive effector -long chain fatty acids are negative effectors

Question 41

Increase insulin, decrease glycogen activates what

Answer 41

Phosphoprotein phosphatase

Question 42

decrease insulin, increase glycogen activates what

Answer 42

protein kinase A

Question 43

How do we long term regulate fatty acid synthesis in liver

Answer 43

Carbohydrate-responsive element binding protein (chREBP)

Question 44

What is Carbohydrate-responsive element binding protein (chREBP)

Answer 44

is a major glucose responsive transcription factor

Question 45

When is the expression of chREBP gene is induced in the liver?

Answer 45

in response to increased glucose uptake

Question 46

ChREBP acts _____ with ____

Answer 46

ChREBP acts synergistically with Sterol Response Element Binding Protein (SREBP)

Question 47

What happens when ChREBP acts synergistically with Sterol Response Element Binding Protein (SREBP)

Answer 47

to induce lipogenic genes such as acetyl CoA carboxylase and fatty acid synthase.

Question 48

What happens to ChREBP under low (basal) glucose concentration?

Answer 48

ChREBP is phosphorylated and resides in the cytosol.

Question 49

What happens to ChREBP when glucose concentration raise?

Answer 49

dephosphorylated and translocated to the nucleus where it binds to Carbohydrate Response Elements (ChoREs) to stimulate transcription of lipogenic genes

Question 50

Where does the dephosphorylated ChREBP translocate and cause?

Answer 50

translocated to the nucleus where it binds to Carbohydrate Response Elements (ChoREs) stimulate transcription of lipogenic genes

Question 51

Besides ChREBP what also translocated to the nucleus

Answer 51

insulin, increases pSREBP-1c to bind to SRE for the stimulation of transcription of lipogenic genes