Proteins

Question 1

Deficient enzyme in MSUD and accumulating AA?

Answer 1

Branched chain alpha ketoacid dehydrogenase

Accumulation of valine, leucine and isoleucine

Question 2

Enzyme deficient in phenylketonuria?

Answer 2

Phenylalanine hydroxylase.

Question 3

Derivatives of tryptophan

Answer 3

Serotonin, niacin, melatonin

Has largest side chain

Question 4

Precursor of homocysteine

Answer 4

Methionine

Question 5

Only imino acid

Contributed to collagen structure

Answer 5

Proline

Question 6

Phenylalanine derivatives

Answer 6

Phenylalanine
Tyrosine
L-dopa
Dopamine
Norepinephrine 
Epinephrine
Thyroxine
Melanin

Question 7

Test for folic acid deficiency

Answer 7

N- formiminoglutamate excretion test

After ingestion of large amounts of histidine, individuals lacking folic acid will excrete increased amounts of FIGIu in urine.

Question 8

Essential amino acids?

Answer 8

PVT TIM HALL always ARGues, never TYRes

Phenylalanine
Valine
Tryptophan
Threonine
Isoleucine
Methionine
Histidine*
Arginine*
Leucine
Lysine

Question 9

Conditionally non-essential AA?

Answer 9

Arginine

Histidine

Question 10

Usual configuration of peptide bonds?

Answer 10

Trans configuration

Question 11

Secondary protein structures include

Answer 11

Alpha helix

Beta sheets

Question 12

Combination of adjacent secondary structures?

Answer 12

Motifs or super secondary structures

Ex. B-a-B units, hair pin, meander, barrel

Question 13

Number of residues per turn in alpha helical?

Answer 13

3.6 AA per turn

Question 14

Aggregation of motifs

Answer 14

Domain (tertiary structure)

Question 15

Characterized by spongiform changes, astrocytic gliomas and neuronal loss secondary to deposition of insoluble protein aggregates in neural cells

Answer 15

Prion diseases
PrPsc accumulation

Creutzfeld Jacob disease
Kuru
Scrapie
Bovine spongiform encephalopathy

Question 16

What protein accumulates in Alzheimer’s disease?

Answer 16

Beta amyloid forming senile plaques and neurofibrillary tangles

Question 17

Heme is composed of:

Answer 17

Protoporphyrin IX

Ferrous iron Fe 2+

Question 18

Major inhibitory NT in spinal cord

Smallest amino acid

Answer 18

Glycine

Question 19

Hemoglobin form that binds oxygen?

Answer 19

Relaxed form (not taut form)

Question 20

AA residue in myoglobin and hemoglobin that plays a role in O2 binding

Answer 20

Histidine

Question 21

Differentiate hemoglobin and myoglobin curves

Answer 21

Hemoglobin: binds 4 O2 molecules, sigmoidal curve

Myoglobin: hyperbolic curve, only 1 O2 molecule

Question 22

Factors that cause shift to the right of HgB curve

Answer 22

CABET do the right thing, LET GO

CO2
Acidity
BPG
Exercise
Temperature

Question 23

Characteristics of methemoglobin

Answer 23

Oxidized for of Hb (Fe3+)
Cyanosis, anxiety, headache, dyspnea
Chocolate cyanosis

Question 24

Treatment for methemoglobin emit

Answer 24

Oral methylene blue, ascot if acid

IV methylene blue

Question 25

Has 200x affinity for Hb | Causes cherry pink color with excess exposure

Answer 25

Carbon monoxide | Carboxyhemoglobinemia

Question 26

Mutations in hereditary sperocytosis Diagnostic test? Treatment?

Answer 26

Shape of RBC becomes spherical Mutations in ankyrin, spectrum, band 3, band 4.1 Anemia, splenomegaly, jaundice Osmotic fragility test Splenectomy

Question 27

AA substitution in sickle cell disease

Answer 27

Glutamate -> valine

Question 28

Medication that increases levels of fetal hemoglobin

Answer 28

Hydroxyurea

Question 29

Substitution in hemoglobin C

Answer 29

Lysine (+) to glutamate (-)

Question 30

Mutation in alpha thalassemia Spectrum of presentation?

Answer 30

Alpha chains Silent carrier, a thalassemia trait, HbH disease, hydrops fetalis

Question 31

Spectrum of B thalassemia presentation?

Answer 31

B thalassemia minor | B thalassemia major

Question 32

Most abundant protein in the body

Answer 32

Collagen

Question 33

Structure of collagen

Answer 33

Triple helix of alpha chains Gly-X-Y X- proline Y- hydroxyproline and hydroxylysine

Question 34

Collagen type affected in Ehler Danlos syndrome? Presentation?

Answer 34

Type III collagen Hyper mobile joints Hyper extensible skin Tendency to bleed Increased risk of berry aneurysms

Question 35

Deficiency in type I collagen

Answer 35

Osteogenesis imperfecta Multiple fractures Blue sclerae Hearing loss Dental imperfections

Question 36

Defect in scurvy

Answer 36

Inability to hydroxylate Y component of collagen due to vit C deficiency Decreased collagen cross linking

Question 37

Defect in Alport syndrome? Presentation?

Answer 37

Type IV collagen SNHL + hematuria, ESRD, RF

Question 38

Characterized by kinky hair and growth retardation Dietary deficiency in copper causing inability to form cross links that strengthen collagen fibers

Answer 38

Menke's syndrome

Question 39

Collagen defect in Epidermolysis bullish

Answer 39

Type VII collagen

Question 40

Inheritance pattern of Marfan's syndrome Gene defect? Cardiac manifestation?

Answer 40

AD Fibrillin gene Ascending aortic dilation and dissection

Question 41

Component present in collagen but absent in elastin

Answer 41

Hydroxylysine | Minimal hydroxyproline