Exam 4 Review

Question 1

Major source of amino acids in pool

Answer 1

Body protein (200 g/day)

Question 2

Hereditary pancreatitis

Answer 2

Overactive trypsin (lack of inhibitor) in the pancreas

Question 3

Enteropeptidase

Answer 3

Cleaves trypsinogen to activate it to trypsin

Question 4

Amino acid absorption

Answer 4

Sodium linked transporters for groups of amino acids with similar characteristics

Question 5

Cystinuria

Answer 5

Defective cysteine (and lysin) transporter in the kidney which leads to lack of cysteine

Question 6

E3 Ub ligase

Answer 6

Recognizes proteins and are polyubiquitinated at a lysine side chain

Question 7

Ubiquitinated amino acid

Answer 7

Lysine

Question 8

M end rule

Answer 8

If a protein has a methionine at the end, it is degraded the slowest

Question 9

DUB

Answer 9

Deubiquitinase, recycles ubiquitin in single Ub units

Question 10

Proteosome

Answer 10

Degrades proteins into 7-10 amino acid peptides

Question 11

What happens when you lack essential amino acids

Answer 11

Break down body protein (muscle)

Question 12

Negative nitrogen balance

Answer 12

Happens in absence of other fuels (trauma), protein is used for energy and making glucose

Question 13

Positive nitrogen balance

Answer 13

Increased protein deposition (building muscle, growing, etc)

Question 14

PLP

Answer 14

Vitamin B6, helps with aminotransferase reactions

Question 15

Location of urea cycle

Answer 15

Periportal region of the liver

Question 16

NAG (n-acetyl glutamate)

Answer 16

Synthesis from acetyl CoA and glutamate (stimulated by arginine), required for CPSI activity

Question 17

OTC deficiency

Answer 17

X-linked, can’t do urea cycle, arginine supplement, high starch diet

Question 18

Glutamine synthase

Answer 18

Found in perivenous liver and brain and muscle for detoxifying blood

Question 19

Treatments of hyperammonemia

Answer 19

• Compounds (benzoate or penylbutyrate) that remove certain non-essential aas (need to use NH4 by synthesizing them)
• Limit the protein intake and use starch
• Supplement with arginine (except argininase deficiency)

Question 20

Amino acids that muscle uses for energy

Answer 20

Branched chain amino acids (isoleucine, valine, leucine) liver does not have branched chain amino acid transferase to utilize these aas

Question 21

Maple syrup urine disease

Answer 21

Defect of branched chain keto acid dehydrogenase

Question 22

PKU defects

Answer 22

Phenylalanine hydroxylase or dihydrobiopterin reductase, High levels of phenylalanine interfere with brain development and function

Question 23

Treatment of PKU

Answer 23

Restrict phenylalanine, supplement tyrosine

Question 24

Vitamin B12 deficiency (4 ways)

Answer 24

• Diet low in vitamin B12
• Lack of intrinsic factor
• Poor absorption in intestine
• Lack of conversion to active (adenosyl or methyl) forms

Question 25

Synthesis of dopamine

Answer 25

Decarboxylation of dopa, S-adenosyl methionine used to make epinephrine for norepinephrine

Question 26

Tyrosinase

Answer 26

Used to make melanin, lacked in albinism

Question 27

Thyroid peroxidase

Answer 27

Found in thyroid, forms thyroxine

Question 28

Amino acids used to inter convert forms of TH4

Answer 28

Serine and glycine

Question 29

Homocystinuria

Answer 29

Lack of cystathionine synthase or lack of folate or B12

Question 30

Synthesis of phosphocreatine

Answer 30

Arginine plus glycine makes guanidinoacetic acid SAM methylates

Question 31

Where components of purines come from

Answer 31

2 Cs and an N- glycine
2 Ns glutamine
2 Cs N10 formyl TH4
N aspartate
C CO2

Question 32

Pyrimidine component origins

Answer 32

Carbamoyl phosphate and aspartate

Question 33

Gout

Answer 33

Elevated Uric acid, HGPRT defect, G6P dehydrogenase defect

Question 34

Allopurinol

Answer 34

Treatment of gout, inhibitor of xanthine oxidase

Question 35

Lesch-Nyhan syndrome

Answer 35

Complete lack of HGPRT

Question 36

Adenosine deaminase deficiency

Answer 36

SCID

Question 37

Ribonucleotide reductase

Answer 37

Uses NADPH to reduce ribose to deoxyribose

Question 38

Protein use in starvation

Answer 38

Used a lot in early starvation (75 g/day) and decreases as starvation continues (20 g/day)

Question 39

3rd stage of starvation

Answer 39

Glycogen almost completely depleted, muscle decreases glucose use increases FA use, proteins degraded to amino acids, TAGs produce FAs for fuel and glycerol for glucose production

Question 40

4th stage of starvation

Answer 40

Brain begins to use ketone bodies, less overall gluconeogenesis

Question 41

5th phase of starvation

Answer 41

Brain almost exclusively uses ketone bodies, erythrocytes and renal medulla still use glucose

Question 42

Sulfonylureas

Answer 42

Inhibit ATP dependent calcium channels (trigger insulin production)

Question 43

Glinides

Answer 43

Inhibit K+ channels

Question 44

Incretin analogues

Answer 44

Mimic gut hormone, increase insulin production

Question 45

DPIV inhibitors

Answer 45

Inhibit the degradation of incretins

Question 46

Alpha glucosidase inhibitors

Answer 46

Block glucose uptake

Question 47

SGLT2 inhibitors

Answer 47

Inhibit glucose reuptake in the kidney

Question 48

Metformin

Answer 48

Blocks gluconeogenesis in liver and increases insulin receptor sensitivity

Question 49

GLP and GIP

Answer 49

Incretins, regulators of the K+ channel

Question 50

Insulin production

Answer 50

Preproinsulin->Proinsulin-> Insulin

Question 51

Insulin signaling

Answer 51

Gluose transport and glycogen synthesis are through lipid signaling
Gene expression is controlled with protein signaling

Question 52

What insulin decreases

Answer 52

Blood glucose, glycogen phosphorylase activity, gluconeogenic reactions, HSL

Question 53

What insulin increases

Answer 53

Glycolysis, FA synthesis, lipoprotein lipase, glucose in adipocytes, aa uptake

Question 54

Lipid triad

Answer 54

High TAG
High VLDL/LDL
Low HDL