Oxidative Metabolism B-Oxidation And Ketone Bodies

Front 1

what is the largest source of energy in the human body?

Back 1

fatty acids

Front 2

what four tissues do not use fatty acids during fasting as an energy source?

Back 2

brain, RBC, adipocytes, intestinal mucosal cells.

Front 3

what are the two sources of fatty acids?

Back 3

diet and de novo synthesis in liver (when blood glucose is high)

Front 4

what are the eight major dietary fatty acids?

Back 4

plamitate, stearate, oleate, linoleate, linolenate, phytanic acid, pristanic acid, and some medium-chain length fatty acids.

Front 5

which of the major dietary fatty acids can be produced in the liver and are therefore are considered nonessential?

Back 5

palmitate, stearate, and oleate

Front 6

what is an example of a saturated long chain?

Back 6

palmitate and sterate

Front 7

what is an example of a monounsaturated long chain?

Back 7

oleate

Front 8

what is an exmaple of a polyunsaturdated long chain?

Back 8

linoleate, linolenate

Front 9

what is an example of a branched chain lon chain?

Back 9

phytanic acid and pristanic acid

Front 10

where are long-chains stored?

Back 10

in adipose as triglycerides

Front 11

what two things stimulate the release of fatty acid from adipose tissue?

Back 11

epinephrine levels and glucagon/insulin ratio

Front 12

what type of lipase cleaves triglycerides?

Back 12

hormone sensitive lipase

Front 13

what do fatty acids have to be bound to to be transported through the blood?

Back 13

albumin

Front 14

what type of protein transports fatty acids into the cell?

Back 14

a fatty acid binding protein

Front 15

where are long-chain fatty acids degraded in? and by what enzyme?

Back 15

mitochondria, ER and peroxisomal membranes; long chain acyl CoA synthetases.

Front 16

where are very long chain and branched chain fatty acids degraded?

Back 16

peroxisomes

Front 17

where are some C10-C12 fatt acids degraded and via what path?

Back 17

ER and omega oxidation

Front 18

in order to be metabolized fatty acids have to be converted to ________

Back 18

fatty acid acyl

Front 19

what does the activation of fatty acids require?

Back 19

2 high energy phosphate bonds

Front 20

where is acetyl CoA synthetase located?

Back 20

cytosol and mitochondrial matrix

Front 21

what are the three ways fatty acyl CoA can be utilized?

Back 21

energy, storage and membrane lipids

Front 22

how are fatty acids transported into the mitochondrial matrix?

Back 22

carnitine-conjugated form

Front 23

what fatty acid chain length does not require carnitine for mitochondrial transport?

Back 23

medium chain fatty acid

Front 24

there are different isoforms of CPTI for three body parts, what are they?

Back 24

liver, muscle and brain

Front 25

which CTP is one the inner mitochondrial membrane?

Back 25

CTPII

Front 26

what transfers carnitine from the matrix to CTPI?

Back 26

Carnitine acylcarnitine translocase (CAT)

Front 27

what is carnitine synthesized from?

Back 27

protein bound lysine

Front 28

what does the synthesis of carnitine require as a methyl donor?

Back 28

S-adenosyl-mehionine (SAM)

Front 29

where is most carnitine stored?

Back 29

skeletal muscle

Front 30

what can carnitine be used as to accelerate fatty acid oxidation?

Back 30

dietary supplement

Front 31

when do deficiencies in carnitine metabolism usually manifest?

Back 31

during fasting or infections

Front 32

what does a deficiency of carnitine metabolism lead to?

Back 32

hypoketotic hypoglycemia (ketone bodies are not produced, glucose is not spared); which leads to elevated blood levels of liver enzymes and ammonia

Front 33

how do you treat a deficiency of carnitine metabolism?

Back 33

high carb, low fat diet rich in medium chain length fatty acids

Front 34

what is wrong in primary carnitine deficiency?

Back 34

lack of carnitine transport into cells

Front 35

primary carnitine deifciency creates a _____ plasma carnitine and acylcarnitine levels and _______ carnitine in urine?

Back 35

low; elevated

Front 36

which deficiency in carnitine metabolism is only found in the liver?

Back 36

carnitine palmitoyl transferase IA deficiency

Front 37

carnitine palmitoyl transferase IA deficiency causes : _______ free carnitine plasma levels and _______ free carnitine/acyl (16-18) carnitine ratio

Back 37

elevated; elevated

Front 38

what two carnitine metabolism deficiencies cause low plasma dree carnitine levels and elevated acyl (C16-18) carnitine levels?

Back 38

carnitine-acylcarnitine translocase deficiency and carnitine palmitoyl transferase II deficiency

Front 39

where does beta oxidation occur?

Back 39

mitochondrial matrix

Front 40

in every cycle of beta oxidation, what three forms of energy are generated?

Back 40

FAD(2H), NADH, and acetyl CoA

Front 41

after each cycle, the length of the fatty acyl CoA decreases by how many carbon(s)?

Back 41

2

Front 42

what does the last cycle of beta oxidation produced due to the even chain length of fatty acids?

Back 42

2 acetyl CoAs

Front 43

Calculate the total energy yield of B-oxidation with a C14 fatty acid chain

Back 43

92

1) 14/2 = 7-1 = 6 cycles
2) (6 x 1.5) + (6 x 2.5) = 6x4= 24 (FAD and NADH)
3) 7 x 10 (acetyl CoA) = 70
4) 24 + 70= 94 - 2 (2 high energy phosphate groups consumption) = 92

Front 44

what type of bond cannot be processed by beta oxidation?

Back 44

cis double bonds

Front 45

what is the process of beta oxidation in unsaturated fatty acids?

Back 45

beta oxidation proceeds as normal until it reaches a cis double bond and stops. The cis double bond is changed to a trans bond and beta oxidation can proceed further.

Front 46

in the beta oxidation of odd chain fatty acids, what is produced in the last cycle?

Back 46

1 acetyl CoA (2 carbons) and 1 propionyl CoA (3 arbons)

Front 47

what is propionyl CoA degraded to in the beta oxidation of odd chain fatty acids?

Back 47

succinyl CoA

Front 48

what can enzyme deficiencies in the degradation of propionyl CoA pathway cause?

Back 48

organic acidemias (propionic or methylalonyl acidemia)

Front 49

what are two acyl CoA dehydrogenase deficiencies?

Back 49

MCAD deficiency and VLCAD deficiency

Front 50

what does MCAD deficiency cause?

Back 50

sudden death during infancy, elevated medium chain acylcarnitine levels in plasma, and elevated medium dicarboxylic acids in urine (omega oxidation)

Front 51

what does VLCAD deficiency cause?

Back 51

elevated very long chain acylcarnitine levels in plasma.

Front 52

what is the treatment for MCAD and VLCAD?

Back 52

glucose and carb-rich diet

Front 53

what is an allosetric inhibitor of CPTI?

Back 53

malonyl CoA

Front 54

what type of acids does omega oxidation produce?

Back 54

dicarboxylic

Front 55

T/F
dicarboxylic acids cannot undergo beta oxidation

Back 55

false

Front 56

for the transportation of very long chain fatty acids to peroxisomes, is carnitine necessary?

Back 56

no, its already in a CoA conjugated form

Front 57

how are branched fatty acids first oxidized?

Back 57

in the alpha position

Front 58

what is the main difference between peroxisomal beta oxidation and mitochondrial beta oxidation?

Back 58

no FAD(2H) is produced in peroxisomal beta oxidation

Front 59

what does peroxisomal beta oxidation produce instead of FAD(2H)?

Back 59

hydrogen peroxide

Front 60

what is refsum disease deficient in?

Back 60

phytanic acid hydroxylase

Front 61

what does phytanic acid hydroxylase do?

Back 61

alpha oxidation of phytanic acid

Front 62

what are the symptoms of refsum disease?

Back 62

retinitis pigmentosa (leads to blindness), lack of ability to smell, deafness, neuropathy, ataxia, elevated plasma phytanic acid levels

Front 63

what are two generalized nervouse system disorders?

Back 63

refsum disease and zellweger syndrome

Front 64

what causes zellweger syndrome?

Back 64

deficient peroxisome biogenesis

Front 65

which one is more serious, zellwegger or refsum?

Back 65

zellwegger

Front 66

where does keton body synthesis take place?

Back 66

liver

Front 67

the ketone body synthesis process involves how many acetyl CoA?

Back 67

2

Front 68

what are the two end products of ketone body synthesis?

Back 68

D-beta-hydroxybutyrate and acetone

Front 69

ketone body utilization is the inverse of which reaction?

Back 69

ketone body synthesis

Front 70

what regulates the amount of acetyl coa in ketone body synthesis?

Back 70

the rate of beta oxidation

Front 71

what happens when the NADH/NAD ratio is high in ketone body synthesis?

Back 71

the malate-oxaloacetate reaction reverses and acetyl-coa cannot enter the TCA cycle and is used for ketone body synthesis.