Beta Oxidation

Question 1

Removal of acetyl CoA fragments from the ends of fatty acids also yielding NADH and FADH2 in the process

Answer 1

Beta oxidation

Question 2

Sites of Beta Oxidation

Answer 2

Liver, Adipose Tissue, Muscle

Mitochondria

Question 3

Substrate of Beta Oxidation

Answer 3

Palmitate

Question 4

Products of Beta Oxidation

Answer 4

Acetyl CoA - 8
NADH - 7
NADH2 - 7

Question 5

Rate Limiting Step of Beta Oxidation

Answer 5

Translocation of fatty acyl CoA from the CYTOSOL to MITOCHONDRIA

CARNITINE PALMITOYL TRANSFERASE I

Question 6

Steps in Beta Oxidation

Answer 6

Oxidation
Hydration
Oxidation
Thiolysis

Question 7

Enzymes collectively known as FATTY ACID OXIDASE

Answer 7

Acyl CoA dehydrogenase
Enoyl CoA hydratase
Hydroxyacyl CoA dehydrogease
Thiolase

Question 8

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

Answer 8

Peroxisomes

Question 9

D.t. inadequate synthesis or renal loss of carnitine

Hypoglycemia - d.t. impaired fatty acid oxidation

Answer 9

Carnitine Deficiency

preterm
liver disease
malnutrition or strictly vegetarian diet
pregnancy
severe infections 
burns or trauma
patient undergoing hemodialysis

Question 10

Affects the LIVER

reduced fatty acid oxidation –> severe hypoglycemia, coma and death

Answer 10

CARNITINE PALMITOYL TRANSFERASE I

Question 11

Affects the CARDIAC and SKELETAL MUSCLE

cardiomyopathy, muscle weakness with myoglobinemia after prolonged exercise

Answer 11

CARNITINE PALMITOYL TRANSFERASE II DEFICIENCY

Question 12

Leads to decreased oxidation of fatty acids with 6-10 carbons

MC INBORN ERROR OF FATTY ACID OXIDATION

Answer 12

Medium Chain Fatty Acyl CoA Dehydrogenase (MCAD) Deficiency

severe hypoglycemia
accumulation of FA in the urine
SIDS

Question 13

Caused by eating the unripe fruit of AKEE TREE

HYPOGLYCIN (toxin) inactivates medium and short chain acyl CoA dehydrogenase –> (-) oxidation and –> hypoglycemia

Answer 13

Jamaican Vomiting Sickness

Question 14

Deficiency of PHYTANOYL COA HYDROXYLASE –> accumulation of PHYTANIC ACID

Answer 14

REFSUM DISEASE

peripheral neuropathy
ataxia
retinitis pigmentosa
abnormalities of skin and bones

Question 15

Cerebrohepatorenal syndrome

Inherited ABSENCE OF PEROXISOMES in all tissues –> marked accumulation of very long chain, saturated unbranched fatty acids in liver and CNS

Answer 15

ZELLWEGER SYNDROME

liver dysfunction with jaundice
marked mental retardation, weakness, hypotonia
craniofacial dysmorphism
early death

Question 16

Inability to transport VLCFA across the peroxisomal membrane –> accumulation in the brain, adrenals, testes

Answer 16

ADRENOLEUKODYSTROPHY (ALD)

neurodegeneration (initial apathy and behavioral change, followed by visual loss, spasticity and ataxia)1
adrenocortical insufficiency
hypogonadism

TREATMENT:

LORENZO’S OIL