Metabolism

Question 1

What is fomepizole

Answer 1

Antidote for alcohol poisoning

It inhibits alcohol dehydrogenase

Question 2

What is disulfiram

Answer 2

Inhibits acetaldehyde dehydrogenase causing acetylaldehyde to accumulate making the patient feel hungover.

Treats alcoholism.

Question 3

What does alcohol metabolism depend on?

Answer 3

Depends mostly on NAD + being converted to NADH

Question 4

Phosphofructokinase 1

Answer 4

rate determening enzyme for glycolysis

Question 5

Fructose - 1,6 bisphosphatase

Answer 5

Rate limiting enzyme for gluconeofenesis

Question 6

Isocitrate dehydrogenase

Answer 6

TCA cycle rate limiting enzyme

Question 7

Glycogen synthase

Answer 7

Glycogenesis Rate limiting enzyme

Question 8

Glycogen phosphorylase

Answer 8

Glycogenolysis RLE

Question 9

Glucose 6 phosphate dehydrogenase

Answer 9

HMP Shunt RLE

Important for NADPH formation

Question 10

Carbamoyl phosphate synthetase II

Answer 10

De novo pyrimidine synthesis RLE

Question 11

Glutamine-phosphoribosylpyrophosphate amidotransferase (PRPP)

Answer 11

De nobo purine synthesis RLE

Question 12

Carbamoyl phosphate synthetase I

Answer 12

Urea cycle RLE

Question 13

Acetyl-CoA carboxylase

Answer 13

Fatty acid synthesis RLE

Question 14

Carnitine acyltransferase I

Answer 14

Fatty acid oxidation RLE

Question 15

HMG-CoA synthase

Answer 15

Ketogenesis RLE

Question 16

HMG-CoA Reductase

Answer 16

Cholesterol synthesis RLE

Question 17

First enzyme in the TCA?

Answer 17

Citrate synthase takes Acetyl-CoA to make isocitrate.

Question 18

Outside sourcs of odd chain fatty acids, branched chain amino acids, and methionine can enter the TCa through what form?

Answer 18

Succinyl CoA

Question 19

the urea cycle can input into the TCA through which form?

Answer 19

Through fumarate formation.

At the expense of also creating urea.

Question 20

what enzyme is specifically inhibited by Arsenic?

Answer 20

Lipoic acid resulting in vomiting, rice water stools, and garlic breath.

Patient is unable to link glycolysis and TCA cycle through mitochondria.

Question 21

what molecule does the TCA utilize in its formation of products?

Answer 21

Utilizes Acetyl-Coa to create NADH, FADH, CO2 and GTP`

Question 22

What is the starting substrate of the TCA?

Answer 22

Citrate.

Ends as oxaloacetate.

Question 23

which steps of the TCA create NADH?

Answer 23

Isocitrate from citate

Succinyl coa from isocitrate
Oxaloacetate from malate

Question 24

Which part of the TCA results in FADH2 formation?

Answer 24

Succinate to fumarate

Question 25

Which part of the TCA results in GTP formation?

Answer 25

Succinyl CoA to succinate reaction.

Question 26

what does the HMP shunt do?

Answer 26

Excess glucose -6- p can be funneled into this pathway to promote NADPH creation.

Also gives ribose for nucleotide synthesis.

Question 27

What role does glucose 6 phosphate dehydrogenase deficiency entail?

Answer 27

NADPH is necessary to keep glutathione reduced which in turn detoxifies free radicals and peroxides.

Decreased NADPH in RBC’s leads to hemolytic anemia. Fava beans and sulfonamides can really ramp this up.

Look for heinz bodies (denatured hemoglobin) and bite cells

Question 28

fructose intolerance

Answer 28

Deficiency in aldolase B
Fructose - 1 - phosphate accumulates causing a deficiency in phosphate.

Look for flare ups after drinking juice and presence of fructose in the urine.

Question 29

What is required for fatty acid synthesis?

Answer 29

Citrate transport from the mitochondria to the cytosol.

Mostly in the liver and lactating mamary glands/ fat tissue.

Question 30

What is required for for long chain fatty acid degradation?

Answer 30

Requires carnitine dependent transport into the mitochondral matrix

Question 31

What happens in a carnitine deficiency?

Answer 31

Inherited defect in transport of long chain fatty acids into the mitochondra.

Toxic accumulation leading to weakness, hypotonia, and hypoketoic hypoglycemia.

Question 32

How are ketone bodies created?

Answer 32

In the liver, fatty acids and amino acids are metabolized to acetoacetate and beta hydroxybutyrate.

In prolonged starvation, and diabetic ketoacidosis, oxaloacetate is depleted for gluconeogenesis.

Question 33

How man calories in...
1g protein
1g carbohydrate
1g fat
1g alcohol

Answer 33

carbs and protein have 4 kcals
fat has 9kcal
1g alcohol has 7kcal

Question 34

How is cholesterol synthesized?

Answer 34

Cholesterol needed to maintain cell membrane integrity and to synthesize bile acid, steroids and vitamin D.

Rate limiting enzyme is HMG-CoA

Question 35

What does HMG-CoA do?

Answer 35

Insulin acts on it to convert HMG-CoA to mevalonate. this occurs in the synthesis of cholesterol.

statins actively inhibit this bad boy

Question 36

Hormone sensitive lipase

Answer 36

Degradation of triglyerides stored in adipocytes

Question 37

Hepatic triglyceride lipase

Answer 37

degradation of triglycerides remaining in IDL

Question 38

What does lipoprotein lipase do?

Answer 38

LPL degrades TGs corculating in chylomicrons and VLDLs and is found on vascular endothelial cell surfaces.

Question 39

What does LCAT do?

Answer 39

Esterfies cholestero to be carried in HDL

Question 40

What is the purpose of apo protein B-48 and B100?

Answer 40

B48 mediates chylomicron secretion

B-100 binds the LDL receptor at the liver.

Question 41

Which lipoproteins carry the most cholesterol?

Answer 41

Lipoproteins LDL and HDL

Question 42

Hyperchylomicronemia

Answer 42

Lacks LPL
Thus excessive chylomicrons, TG and cholesterol floating in blood.

Causes pancreatitis and hepatosplenomegaly

Question 43

Familial hypercholesterolemia

Answer 43

Increased LDL and cholesterol

Defected LDL receptors
Causes accelerated atherosclerosis

Question 44

Hypertriglyceridemia

Answer 44

Hepatic overproduction of VLDL

Causes hypertriglyceridemia that can lead to pancreatitis.