Biochemistry 2- Boards & Beyond

Question 1

What amino acids do histones have a high content of

Answer 1

Lysine, arginine

Question 2

What substitution occurs with sickle cell anemia

Answer 2

Polar glutamate for nonpolar valine

Question 3

What are the 2 strictly ketogenic amino acids

Answer 3

Leucine, lysine

Question 4

What is the cofactor for phenylalanine hydroxylase

Answer 4

BH4 (tetrahydrobiopterin)

Question 5

What is the order of tyrosine metabolism

Answer 5

Tyrosine, DOPA, dopamine, norepinephrine, epinephrine

Question 6

What enzyme is deficiency in oculocutaneous albinism

Answer 6

Tyrosinase

Question 7

What is deficient in alkaptonuria

Answer 7

Homogentisic acid oxidase

Question 8

What is the classic findings with alkaptonuria

Answer 8

Dark urine when left standing, arthritis, black pigment in cartilage/joints (calcification in IV discs), urine discoloration in children, dark pigment

Question 9

What are common serotonin effects in carcinoid syndrome

Answer 9

Diarrhea (serotonin stimulates GI motility), increased fibroblast growth and fibrogenesis (leading to valvular lesions), flushing

Question 10

What is the issue with Hartnup disease and how is it inherited

Answer 10

Absence of AA transport in proximal tubule; autosomal recessive

Question 11

What are some common symptoms with Hartnu disease

Answer 11

Pellets (hyperpigmented rash, exposed areas of skin, red tongue, diarrhea, dementia)

Question 12

What are the branched chain Amino acids

Answer 12

Valine, leucine, isoleucine

Question 13

What is the deficiency in maple syrup urine disease and what are some symptoms

Answer 13

Deficiency of alpha keto acid dehydrogenase; increased branched chain AAs and alpha-ketoacids in plasma; neurotoxicity is main problem, urine smells sweet

Question 14

What are some common symptoms of homocystinuria

Answer 14

Lens dislocation, long limbs, chest deformities, osteoporosis in childhood, blood clots, early atherosclerosis

Question 15

What is the alanine cycle used fr

Answer 15

By the muscles to transfer nitrogen to liver

Question 16

What is the rate limiting enzyme in the urea cycle

Answer 16

Carbamoyl phosphate synthetase I

Question 17

What is the most common defect in urea cycle

Answer 17

Ornithine transcarbamylase

Question 18

What is another name for vitamin B1

Answer 18

Thiamine

Question 19

What is the term for thiamine deficiency not associated with alcohol and how does it present

Answer 19

Beriberi; dry has polyneuritis, muscle weakness; wet has tachycardia, high-output heart failure, edema

Question 20

What is another name for vitamin B2

Answer 20

Riboflavin

Question 21

What vitamin is required for synthesis of niacin from tryptophan

Answer 21

Vitamin B6

Question 22

What are the 4 Ds associated with niacin deficiency

Answer 22

Pellagra: dermatitis, diarrhea, dementia, death

Question 23

What is another name for vitamin B5 and what is it used in

Answer 23

Pantothenic acid; coenzyme A

Question 24

What is another name for vitamin B6

Answer 24

Pyridoxal phosphate

Question 25

What type of anemia can occur with vitamin B6 deficiency

Answer 25

Sideroblastic anemia (because iron cannot be incorporated into heme and so it accumulates in RBC cytoplasm)

Question 26

What is the only B vitamin with potential toxicity

Answer 26

B6

Question 27

What is biotin (vitamin B7) cofactor for

Answer 27

Carboxylation enzymes

Question 28

What vitamin is required for conversion of dopamine to norepinephrine

Answer 28

Vitamin C

Question 29

What vitamin can be in excess with sarcoidosis

Answer 29

Vitamin C

Question 30

What deficiency should you think of with impaired sexual development, poor wound healing, and loss of taste

Answer 30

Zinc

Question 31

What heredity are most lysosomal storage diseases

Answer 31

Autosomal recessive

Question 32

What is deficient in fabry's disease, what accumulates

Answer 32

Alpha-galactosidase A is deficient; ceramics trihexoside accumulates

Question 33

What is the classic case seen with Fabry's disease

Answer 33

Child with pain in hands/feet, lack of sweat, skin findings (angiokeratomas)

Question 34

What is deficient in gaucher disease and who is it most common in

Answer 34

Deficiency of glucocerebrosidase; ashkenazi Jews

Question 35

What should you think of with crinkled paper macrophages

Answer 35

Gaucher disease

Question 36

What is the common presentation of gaucher disease

Answer 36

Hepatosplenomegaly, severe bone pain, easy bruising from low platelets, join problems

Question 37

What is deficient with Niemann pick disease

Answer 37

Acid sphingomyelinase

Question 38

What is the classic case of Niemann pick disease

Answer 38

Previously well/healthy child, weakness/loss of motor skills, enlarged liver or spleen on physical exam, cherry red spot

Question 39

What are some conditions that commonly have cherry red spot

Answer 39

Niemann-pick, tay-Sachs, central retinal artery occlusion

Question 40

What is deficient with Krabbes disease

Answer 40

Galactocerebroside

Question 41

What is the classic case of Krabbes disease

Answer 41

Presents at 6 months, only neuro symptoms, progressive weakness, absent reflexes

Question 42

What is deficient with Tay Sachs and what accumulates

Answer 42

Deficiency of hexosaminidase A; GM2 ganglioside accumulates

Question 43

What is the presentation of Tay Sachs

Answer 43

Presents 3-6 months, weakness, exaggerates startle reaction, progresses to seizures/vision/hearing loss, cherry red spot, NO hepatosplenomegaly

Question 44

What is the classic Path finding with Tay Sachs

Answer 44

Lysosomes with onion skinning

Question 45

What is the deficiency with metaochromatic leukodystrophy

Answer 45

Arylsulfatase A

Question 46

What are common presentations of metachromatic leukodystrophy

Answer 46

Roughly 2 years old, ataxia, hypotonia

Question 47

What is deficient with Hurler's syndrome and what accumulates

Answer 47

Deficiency of alpha-L-iduronidase; accumulation of heparin and dermatan sulfate

Question 48

What are some symptoms of hurler's syndrome

Answer 48

Corneal clouding, coarse facial features, short stature, hepatosplenomegaly

Question 49

What is the heredity of hunters syndrome

Answer 49

X-linked recessive

Question 50

What is deficient with Hunter's syndrome

Answer 50

Iduronate-2-sulfatase

Question 51

What makes hunter's syndrome different from hurlers

Answer 51

No corneal clouding, later onset, behavioral problems, learning difficulty, trouble sitting still, often aggressive behavior