35. beta oxidation

Question 1

removal of acetyl CoA from the ends of fatty acids

Answer 1

beta-oxidation

Question 2

products of beta-oxidation

Answer 2

• 8 Acetyl CoA -> citric acid cycle
• 7 NADH -> ETC
• 7 FADH2 -> ETC

Question 3

where does beta oxidation occur

Answer 3

muscle
liver
•mitochondria

•fatty acid activation occurs in the cytosol

Question 4

substrate of beta-oxidation

Answer 4

palmitate

Question 5

rate limiting step in beta oxidation

Answer 5

translocation of fatty acyl coa from cytosol to the mitochondria
Enz : carnitine-palmitoyl transferase

Question 6

Transport of fatty acyl coa to the mitochondria involves

Answer 6

1. activation of the fatty acid ≈ fatty acyl synthetase
2. attachment of fatty acyl to carnitine in the outer mitochondrial membrane ≈ carnitine acyltransferase-1
3. fatty acyl-carnitine is shuttled through the inner membrane
4. transfer of fatty acyl group back to a CoA in mitochondrial matrix
   ≈ carnitine acyltransferase-2

Question 7

this enzyme activates the fatty acid

Answer 7

fatty acyl synthetase

Question 8

degradation of faty acyl coa are a sequence of these steps, repeated 7 times

Answer 8

Oxidation —> Hydration —> Oxidation —> Thiolysis

OHOT

Question 9

enzymes collectively known as fatty acid oxidase

Answer 9

(4)
•fatty acyl coa dehydrogenase
•∆2 enol coa hydratase
•3-hydroxyacyl coa dehydrogenase
•thiolase

Question 10

how much ATP in NADH

Answer 10

2.5 ATP each

Question 11

how much ATP in FADH2

Answer 11

1.5 ATP each

Question 12

how much ATP in acetyl coa

Answer 12

10 ATP each

Question 13

Net atp yield of palmitate

Answer 13

108 ATP -2 ATP (activation)

= 106 ATP

Question 14

oxidize very long chains of fatty acids (C20, C22)

Answer 14

peroxisomes

Question 15

oxidation of unsaturated FAs require this additional enzyme

Answer 15

3,2 enoyl-CoA isomerase

Question 16

oxidation of FA with an odd number of carbon atoms will yield

Answer 16

acetyl Coa and a molecule of propionyl CoA

Question 17

propionyl CoA is converted to ____, a TCA intermediate

Answer 17

succinyl CoA

Question 18

propionyl CoA carboxylase requires

Answer 18

biotin

Question 19

methylmalonyl CoA mutase requires

Answer 19

vit B12

Question 20

rate limiting enzyme of lipogenesis

Answer 20

acetyl CoA carboxylase

Question 21

subcellular location of lipogenesis

Answer 21

cytosol

Question 22

subcellular location of beta oxidation

Answer 22

mitochondria

Question 23

transport mechanism of lipogenesis

Answer 23

citrate shuttle

Question 24

transport mechanism of beta-oxidation

Answer 24

carnitine shuttle

Question 25

repetitive steps of lipogenesis

Answer 25

* condensation * reduction * dehydration * reduction CRDR

Question 26

product of lipogenesis

Answer 26

palmitate

Question 27

product of beta oxidation

Answer 27

8 acetyl CoA 7 NADH 7FADH2

Question 28

activator of lipogenesis

Answer 28

citrate

Question 29

inhibitor of lipogenesis

Answer 29

long-chain fatty acetyl CoA

Question 30

inhibitor of beta oxidation

Answer 30

malonyl coa

Question 31

hormonal state favoring lipogenesis

Answer 31

high insulin

Question 32

hormonal state favoring beta -oxidation

Answer 32

high glucagon

Question 33

lipid malabsorption manifests as

Answer 33

steatorrhea

Question 34

lipid malabsorption results to

Answer 34

fat soluble vitamin and essential fatty acids deficiency

Question 35

possible causes of lipid malabsorption

Answer 35

``` liver disease pancreatic disease cholelithiasis shortened bowel intestinal mucosal defects ```

Question 36

deficiency of essential FA results in

Answer 36

``` ichthyosis (scaly dermatitis) hair loss poor wound healing visual neurologic abnormalities ```

Question 37

carnitine deficiency causes

Answer 37

``` preterm infants liver disease malnutrition or strictly vegetarian diet pregnancy severe infections burns trauma hemodialysis ```

Question 38

presents with •hypoglycemia due to impaired fatty acid oxidation •lipid accumulation with muscular weakness

Answer 38

carnitine deficiency

Question 39

tx of carnitine deficiency

Answer 39

oral supplementation with carnitine

Question 40

carnitine-palmitoyl transferase I deficiency affects the

Answer 40

liver

Question 41

carnitine-palmitoyl transferase II deficiency affects the

Answer 41

cardiac and skeletal muscle | -cardiomyopathy, muscle weakness with myoglobinemia after prolonged exercise

Question 42

leads to dec oxidation of FAs with 6-10 carbons

Answer 42

MCAD deficiency medium chain fatty acyl coa dehydrogenase deficiency

Question 43

most common inborn eror ofFA oxidation

Answer 43

MCAD deficiency medium chain fatty acyl coa dehydrogenase deficiency

Question 44

inheritance pattern of MCAD deficiency

Answer 44

autosomal recessive

Question 45

MCAD deficiency higher indcidence in

Answer 45

norther europeans

Question 46

can manifest as severe hypoglycemia accumulation of FA in urine sudden infant death syndrome

Answer 46

MCAD deficiency medium chain fatty acyl coa dehydrogenase deficiency

Question 47

tx of MCAD deficiency

Answer 47

1. avoidance of fastig | 2. IV glucose during acute episodes

Question 48

caused by eating unripe fruit of the akee tree

Answer 48

jamaican vomiting sickness

Question 49

toxin causing jamaican vomiting sickness

Answer 49

hypoglycin

Question 50

hypoglycin inactives

Answer 50

medium and short chain acyl CoA dehydrogenase - inhibit beta oxidation

Question 51

this disease is caused by deficiency of phytanoyl hydroxylase that leads to accumulation of phytanic acid

Answer 51

Refsum disease

Question 52

Tx of refsum disease

Answer 52

diet low in phytanic acid | avoid dairy products, ruminant fat and meat

Question 53

* presents with neurodegeneration (initial apathy and behavioral change, visual loss, spasticity, ataxia) * adrenocortical insufficiecy * hypogonadism

Answer 53

Adrenoleukodystrophy (ALD)

Question 54

presents with •liver dysfunction w/ jaundice •marked mental retardation, weakness, hypotonia •cranofacial dysmorphism - high forehead, shallow orbits, hypertelorism, high arched palate, abnormal helices of ears, retrognathia •early death

Answer 54

zellweger syndrome

Question 55

* peripheral neuropathy and ataxia * retinitis pigmentosa * abnormalities in skin and bones

Answer 55

refsum disease

Question 56

* cerebrohepatorenal syndrome * inherited absences of peroxisomes in all tissues * marked accumulation of very long chain, saturated, unbranched, fatty acids in the liver, and central nervous system

Answer 56

Zellwegger syndrome

Question 57

inability to transport VLCFAs across the peroxisomal membrane leads to accumulation in the brain, adrenals and testes

Answer 57

adrenoleukodystrophy

Question 58

tx of ALD | Adrenoleukodystrophy

Answer 58

Adrenal hormone replacement therapy | Hematopoetic stem cell transplantation