YOUNGER BLOCK 2

Question 1

Unsaturated FA

Answer 1

Double bonds present

• cause kinks
• three carbon intervals
• reduces melting temp, increases fluidity

Question 2

Why do membrane phospholipids often contain double bonds?

Answer 2

Because they are LCFA (the longer the chain, the higher the melting temp) and needs the double bonds there to lower the melting temp and increase fluidity

Question 3

What are 2 essential FA?

Answer 3

• a-linolenic acid

- linoleic acid

Question 4

Arachidonic acid

Answer 4

Becomes essential is linoleic acid is deficient in the diet

Question 5

Linoleic acid

Answer 5

• essential FA
• omega 6
• precursor for other omega 6 FA
• arachidonic acid becomes essential if this is deficient

Question 6

A-linoleic acid

Answer 6

• precursor for omega 3 FA
• important for growth and development
• essential FA

Question 7

Arachidonic acid

Answer 7

• substrate for prostaglandin

- becomes essential id linoleic acid is deficient in diet

Question 8

FA less than 12 carbons

Answer 8

-short and medium chain

Question 9

FA greater than 22 C

Answer 9

VLCFA

Question 10

Where are LCFA synthesized>

Answer 10

de novo synthesis

Question 11

Where are VLCFA synthesized ?

Answer 11

Brain tissue

Question 12

Dietary lipids

Answer 12

• TAG
• phospholipids
• free FA
• cholesterol
• cholesterol esters

Question 13

Acid lipase

Answer 13

• lingual lipase
• gastric lipase
• target TAG containing short and medium chain FA
  
  • can get through to blood stream without micelle

Question 14

What are the two complimentary actions of emulsification in the small intestines?

Answer 14

• mechanical agitation
• bile salts secretion
  
  • detergent
  • don’t coalesce
  • allows pancreatic enzymes more surface area

Question 15

What are the pancreatic enzymes responsible for TAG digestion

Answer 15

• pancreatic lipase

- colipase

Question 16

Phospholipase A2

Answer 16

• phospholipid digestion

- removes the fatty acid from position 2 from arachidonic acid

Question 17

What do gut endocrine cells sense?

Answer 17

CCK senses lipids and proteins, causes reduction of gut motility

Secretin senses low pH and secretes bicarbonate

Question 18

Micelles

Answer 18

• amphipathic lipids

- DEAK

Question 19

How do short and medium chain FA get into blood stream?

Answer 19

They don’t need a micelle

Question 20

Fatty acyl-CoA synthetase (thiokinase)

Answer 20

-loads fatty acyl-CoA for entry into chylomicron

Question 21

Chylomicron

Answer 21

• ER—lymph system—-blood
• contain B-48
• carries neutral lipids such as TAG and DEAK vitamins

Question 22

Lipoprotein lipase

Answer 22

• clip FA from chylomicron
• synthesized and secreted by muscle and adipose

Remnants interact with liver cells and are endocytosed, this is where the vitamins get absorbed into the body

Question 23

Lipid malabsorption

Answer 23

Poor digestion such as inability to secrete the proper amount of bile.
Shortened bowel disease

Question 24

Cystic fibrosis

Answer 24

• cant take up fat soluble vitamins
• pancreatic insufficiency, significant reduction in dietary calories, decrease fat soluble vitamin up take
• treatment includes: enzyme replacement, and fat soluble vit supplements

Question 25

De novo synthesis

Answer 25

- well fed - cytosol of liver and mammary glands of lactating mammals - cytosolic acetyl CoA is carbon source for growing FA chain (originate in mitochondria) - energy source: ATP and NADPH

Question 26

Which membrane of the mitochondria is hard to get across?

Answer 26

The inner mitochondrial membrane

Question 27

ACC

Answer 27

- dimers in cytosol - coalesce to larger molecule which is active - takes CO2/energy and carboxylase acetyl CoA to malonyl CoA - RATE LIMITING STEP

Question 28

Presence of citrate

Answer 28

Signals ACC

Question 29

Short term regulation of ACC

Answer 29

- AMPK reversibly phosphorylates and inhibits ACC | - LCFA presence also inhibits it (substrate)

Question 30

Long term regulation of ACC

Answer 30

- prolonged high calorie, high carb increases ACC synthesis | - low calorie or high fat diet reduces ACC synthesis

Question 31

FAS

Answer 31

- multifunctional dimeric enzyme - 7 different enzymatic activities - acyl carrier protein (ACP) - holding site for cysteine 2 C from malonyl CoA ATP NADPH

Question 32

Predominant source of the NADPH required for FA synthesis

Answer 32

HMP shunt

Question 33

Palmitate

Answer 33

Elongated at the smooth ER Reduction of NADPH 2 C from malonyl CoA

Question 34

Desaturation of FA chains

Answer 34

Add double bonds to maintain fluidity at body temp

Question 35

Carbon 2 on TAG

Answer 35

Unsaturated FA of varied length

Question 36

Where is TAG generated ?

Answer 36

In liver and adipose

Question 37

TAG generation in liver

Answer 37

Glycerol kinase converts free glycerol to glycerol phosphate simply by adding a phosphate group

Question 38

What do chylomicrons deliver?

Answer 38

Exogenous dietary lipids

Question 39

What do VLDLS deliver?

Answer 39

De novo synthesized lipids

Question 40

Adipose lipase

Answer 40

-constitutive, low level release of FA

Question 41

Hormone sensitive lipase

Answer 41

- major role in regulated TAY lipolysis and release - much more than adipose lipase - heavily influenced by insulin

Question 42

What is the major pathway for obtaining energy from FA

Answer 42

B-oxidation in the mitochondria | FA must be in the fatty acyl CoA

Question 43

Products of B oxidation

Answer 43

Acetyl CoA, NADH, FADH2q

Question 44

Carnitine shuttle

Answer 44

- imports LCFAs into the mitochondria - CATI on outer mitochondrial membrane acyl groups transferred from CoA to carnitine. Regulated by malonyl CoA - CATII on matrix side acyl group transfer from carnitine to CoA

Question 45

CAT I inhibition

Answer 45

Malonyl CoA | -preventing LCFA transfer from CoA to carnitine

Question 46

Source of carnitine

Answer 46

Diet | Synthesized in liver/ kidney

Question 47

Where is most of the carnitine

Answer 47

Skeletal muscle

Question 48

Secondary carnitine deficiency

Answer 48

- liver disease - malnutrition - dialysis - pregnancy

Question 49

Primary carnitine deficiency

Answer 49

congenital deficiencies | CAT I and CAT II defect

Question 50

Energy molecules for B oX

Answer 50

NADH FADH2 Acetyl CoA--produce ketone bodies in liver to be used by peripheral tissue

Question 51

What vitamin is required for odd number of carbon degeneration?

Answer 51

Vitamin B12

Question 52

Saturated or unasturated FA release less energy?

Answer 52

Unsaturated | -require additional enzymes

Question 53

MCAD deficiency

Answer 53

Decreased oxidation of 6 to 10 carbon FA | -hypoglycemia

Question 54

Ketone bodies

Answer 54

- produced in liver from B-oxidation derived acetyl CoA - acetoacetate and 3-hydroxybutarate transported in the blood to peripheral tissues - peripheral cells convert ketone bodies back into acetyl CoA, a substrate for the TCA cycle - decrease the demand on blood glucose

Question 55

Hypoketosis

Answer 55

-fatty acid oxidation disorder due to decreased acetyl CoA availability

Question 56

Hypoglycemia

Answer 56

-fatty acid disorder due to increased reliance on glucose for energy

Question 57

HMG CoA synthase=

Answer 57

- rate limiting step in ketone body synthesis and is present only in the liver to significant amounts - makes 6-C chain to make ketone

Question 58

Can liver uses ketone bodies as fuel?

Answer 58

No because it lacks thiophorase | -extrahepatic cells having mitochondria can conduct this process

Question 59

Imbalances in use and production of ketone bodies

Answer 59

Cause ketone ketone bodies to rise - blood (ketonemia) - urine (Ketonuria)

Question 60

How can ketoacidosis be caused?

Answer 60

Fasting | -decreases blood volume increases H+ concentration causing severe acidosis

Question 61

Why is thromboxane synthesis more severely affected by NSAIDs and how does it affect coagulation?

Answer 61

Inhibits the COX step in the formation of both prostacyclin and thromboxanes -platelets cannot synthesize new COX because no nucleus and significantly limits the thermogensis potential

Question 62

Glucocorticoids and inhibited phospholipase A2

Answer 62

- inhalers - steroidal anti-inflammatory drug - promotes gene level up-regulating of phsopholipase A2 inhibitor