Biochem UWorld

Question 1

Collagenases are what kind of enzyme

Answer 1

MMP matrix metalloproteinases

Question 2

Marfan’s gene

Answer 2

Fibrillin-1 gene

Question 3

The PI3K/Akt/mTOR pathway

Answer 3

anti-apoptosis, cellular proliferation, and angiogenesis. mutations in these lead to cancer pathogenesis

Question 4

IP3

Answer 4

activates Protein Kinase C

Question 5

Branched chain fatty acids undergo what for breakdown

Answer 5

Alpha-oxidation

Question 6

problems with ubiquitin-proteasome system can lead to

Answer 6

Parkinson and Alzheimer’s

Question 7

Mousy odor in a child with fair colored features

Answer 7

Phenylketonuria. Tyrosine is an essential enzyme because they can’t make it from phenylalanine anymore. Can’t produce melanin either.

Question 8

PKU caused by

Answer 8

mutation in phenylalanine hydroxylase enzyme

Question 9

Nitrates in diet do what to DNA

Answer 9

deaminate cytosines, adenines, and guanines

Question 10

In base excision repair….

Answer 10

AP endonuclease cleaves 5’ side before lyase cleaves 3’ side

Question 11

Iron deficient anemia can present with

Answer 11

Dysphagia (esophageal webs) and dysfigured fingernails (spoon nails (koilonychia))

Question 12

Plummer-Vinson or Patterson Kelly syndrome

Answer 12

Iron deficiency anemia with dysphagia from esophageal webs??

Question 13

Pernicious anemia classic presentation

Answer 13

Older, mentally slow woman of northern European descent who is “lemon colored” (anemic and icteric) with a smooth shiny tongue of atrophic glossitis and a broad shuffling gait.

Question 14

Cobalamin deficiency path

Answer 14

Homocystinemia due to impaired methionine re-synthesis.

Question 15

Maturing erythrocytes lose the ability to synthesize heme when what happens…

Answer 15

When they lose their mitochondria

Question 16

HbC is made of what

Answer 16

Lysine instead of glutamate residue so the Hb molecule is more positive and does not electrophorese as far compared to even HbS (valine is nonpolar)