Goljan High Yield Biochemistry EC

Question 1

Rate limiting reaction in cholesterol synthesis

Answer 1

HMG Co reductase

Question 2

Findings in PKU

Answer 2

Mousy odor
Tyrosine missing hence it must be supplied in the diet
Can diagnose by amniocentesis and finding the abnormal gene
Eliminate phenylalanine from diet (no nutrasweet)

Question 3

I cell disease

Answer 3

Inability to phosphorylate the mannose residues of potential lysosomal enzymes in the golgi
Cannot be taken up by lysosomes to degrade complex substrates

Question 4

Number of glucoses necessary to build palmitic acid (16C compound)

Answer 4

4 glucoses

Each glucose produces 2 acetyl CoA w/ 2 carbons each

Question 5

Insulin lack in DKA

Answer 5

Decreased glycolysis, glycogenesis, fatty acid synthesis, storage of fat in adipose

Question 6

Uncoupling agents (alcohol, salicylates)

Answer 6

Produces brown fat from increased heat from reactions trying to increase the generation of more protons to make ATP

Question 7

Von Gierke’s

Answer 7

decreased glucose-6-phosphatase (gluconeogenic enzyme) with hypoglycemia and increase in glucose-6-phosphate with production of normal glycogen in the liver and kidneys
Stimulation tests with glucagon, fructose.
Cannot increase glucose levels owing to missing enzyme

Question 8

Biochemical processes in both cytosol and mitochondria

Answer 8

Urea cycle, heme synthesis, gluconeogenesis

Question 9

Female with pheochromocytoma, what dietary alteration?

Answer 9

Decrease phenylalanine and tyrosine in the diet

Question 10

Pregnant female with PKU, what diet?

Answer 10

Low phenylalanine
High tyrosine
(avoid neutrasweet)

Question 11

Lesch Nyhan

Answer 11

Absent HGPRT

Self-mutilation, hyperuricemia, mentalretardation

Question 12

Glucokinase

Answer 12

Only in the liver
High Vm and Km
Not inhibited by G6P

Question 13

Hexokinase

Answer 13

In all tissues
Low Vm and Km
Inhibited by G6P

Question 14

Branched chain amino acids/Maple syrup urine disease

Answer 14

Only muscle van metabolize maple syrup urine disease

Question 15

Key enzyme in gluconeogenesis

Answer 15

Fructose-1-6-bisphosphatase (catalyses conversion of F16BP to F6P)

Question 16

Locations of glucose-6-phosphatase (gluconeogenic hormone)

Answer 16

Liver, kidney, intestinal epithelium

Question 17

Shuttles and what they carry

Answer 17

Carnitine (even chained fatty acids)

Malate (NADH)

Question 18

Functions of LDL

Answer 18

Vit. D synthesis
Steroid synthesis
Cell membranes
Synthesis of bile salts

Question 19

Acetyl CoA uses

Answer 19

FA synthesis
CH synthesis
Ketone body synthesis
(NOT a substrate for gluconeogenesis)

Question 20

Urea cycle

Answer 20

Method of eliminating ammonia

Located in hepatocyte

Question 21

Epinephrine given and only small branches chains found

Answer 21

Debrancher deficiency

Question 22

Origin of apolipoproteins

Answer 22

apo-100 =Liver

apo-48=intestine

Question 23

Rate limiting step in glycogenolysis

Answer 23

glycogen phosphorylase

Question 24

Reason why liver can not use ketones for fuel

Answer 24

liver cannot activate acetoacetate in the mitochondria which requires succinyl CoA: Acetoacetate CoA transferase in order to convert AcAc into acetoacetyl CoA

Question 25

McArdles disease

Answer 25

absent muscle phosphorylase Increased glycogen in muscle No increase in lactic acid after exercise

Question 26

Pregnant woman is a beer drinker, what supplements does she need?

Answer 26

Folate (alcohol increases loss) Fetal alcohol syndrome possible (Irone is NOT affected by beer drinking)

Question 27

Insulin

Answer 27

Key hormone in fed state

Question 28

Glucagon

Answer 28

Key hormone in fasting state

Question 29

Mannose-6-phosphate

Answer 29

Involved in transfer of dolichol in the RER in the synthesis of O-linked glycosides

Question 30

Major source of NADPH

Answer 30

HMP shunt | Malate dehydrogenase reaction to a lesser extent

Question 31

Mutation changes an amino acid sequence, which one would have the greatest effect on migration in a serum protein electrophoresis?

Answer 31

One with the most negative charges (acidic)=Glutamine | Most basic=Arginine

Question 32

Mechanism of ketoacidosis in DKA

Answer 32

Increased beta oxidation of fatty acids and production of acetyl CoA (used by liver to synthesize ketone bodies)

Question 33

Promoter location

Answer 33

Linear gene drawing with labels, pick upstream locations

Question 34

Energy source for protein synthesis

Answer 34

GTP

Question 35

Isoenzyme with 2 genes, 4 subunits

Answer 35

``` LDH isoenzymes LLLL LLLH LLHH LHHH HHHH ```

Question 36

Second messengers

Answer 36

ANP=cGMP Insulin=TK Nicotinic=ion channels

Question 37

Best method of detecting relatedness of new bacteria

Answer 37

Restriction fragment length polymorphism

Question 38

Enzyme used for PCR

Answer 38

DNA polymerase

Question 39

Source of glucose in a brain in starvation

Answer 39

Alanine (transaminated to pyruvate)

Question 40

Glutamine

Answer 40

Most abundant amino acid | Carries ammonia in nontoxic form

Question 41

Tyrosine

Answer 41

Thyroid hormones Melanin Neurotransmitters Decreased in PKU

Question 42

Glycine

Answer 42

Inhibitory neurotransmitter Blocked by tetanus toxin Heme synthesis Synthesis of bile acids

Question 43

Hepatic encephalopathy

Answer 43

Increase in aromatic amino acids (phenylalanine, tyrosine, tryptophan [PTT]) Increased synthesis of false neurotransmitters (GABA, octopamine) in hepatic encephalopathy Branched chain amino acids inhibit synthesis of false neurotransmitters (given to Rx)