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Flashcards in Biochem yay... Deck (46):
1

a Pyruvate DH deficiency will lead to build up of __________

Lactic acid

2

name the 2 exclusively ketogenic amino acids

((* ie: won't feed into glycolysis at all... can give to pts with Pyruvate DH deficiency and they won't contribute to more lactic acid))

Leucine & Lysine

3

If delta G is negative:

the reaction favors the products and Keq > 1

4

If delta G is positive:

the reaction favors the substrates and Keq < 1

Note:
(Keq can never be zero & a Keq = 1 would mean delta G is 0)

5

diseases of mitochondrial DNA are passed from ______ to ________

mother to all of her offspring

6

deletion or insertion of 1 nucleotide is a __________ mutation

Frameshift (any deletion or insertion NOT in multiples of 3)

7

a single base substitution that causes the codon & the amino acid to change

Missense mutation

8

pt with large amounts of orotic acid in the urine--- you should supplement them with _______

Uridine --improves symptoms by inhibiting CPS II enzyme

9

Nitric oxide synthase (eNOS) synthesizes NO from which amino acid??

L- Arginine

10

mechanism of Streptomycin

binds 30s ribosomal subunit & impairs INITIATION of translation

11

Which bacterial enzyme has 5' --> 3' exonuclease activity?

((as well as 3'--> 5' exonuclease activity and 5'---> 3' polymerase ))

DNA pol 1

- proofreading
- removes RNA primers in 5--> 3 direction and fills in holes left by the primers too

12

bacterial mRNA can be polycistronic...meaning _____________

one mRNA codes for several proteins

13

liver glycogen stores usually become depleted after _________ hours of fasting

12-18 hours

-after that gluconeogenesis is the main way to maintain blood glucose

14

________ is a glucose sensor in beta cells, inactivating mutations of this enzyme result in mild hyperglycemia that can be made worse in pregnancy

Glucokinase

15

infant with hypertonicity and diapers that smell like burnt caramel

Maple syrup urine disease

-defect in a-keto acid DH
-inable to break down branched chain amino acids (Valine, Isoleucine and Leucine)

16

What 4 enzymes need Thiamine (B1) to function?

1) Pyruvate DH
2) a-ketoglutarate DH
3) Transketolase
4) branched chain alpha-ketoacid DH

17

Which TCA cycle enzyme uses FAD (from Riboflavin (B2)) ??

Succinate DH (converts Succinate to Fumarate)

-uses FAD --> makes FADH2

18

Which autoantibody has the highest specificity for RA?

Anti-CCP (cyclic citrullinated peptide)

-ANA & RF are not very specific

19

Which B vitamin is needed for transamination reactions?

B6 (Pyridoxine)

20

Aldose reductase converts glucose ---> sorbitol and _______ _______ converts sorbitol into fructose (if present in the cell)

Sorbitol DH

-tissues like the lens, renal papillae, retina & schwann cells have little Sorbitol DH (and therefore sorbitol accumulates in diabetics and causes osmotic damage to these tissues)

21

Which amino acid becomes essential in a baby with PKU?

Tyrosine

22

deficiencies of vitamins ___, ____, & ___ are associated with high levels of homocysteine

(which is associated with thrombosis/ atherosclerosis)

B6, B12, & Folate

23

Where in the cell do 5' capping, poly-A tail addition, & intron splicing happen?

Nucleus

24

chronic vitamin A toxicity (overuse) symptoms

alopecia, dry skin, hyperlipidemia, hepatosplenomegaly, liver damage, vision changes / papilledema

25

this mineral activates many enzymes

Calcium

26

______ are made by RNA pol II in the nucleus, help remove introns from the RNA & thus are necessary for making mRNA

snRNPs

27

the Nitrogen atoms in Urea are derived from ___ & ____

NH3 & Aspartate

(note: CPS I is the RLS in the urea cycle)

28

Lead blocks ___________ in the heme biosynthetic pathway

ALA dehydratase
(delta -Aminolevulinate DH)

-thus in Lead poisoning, delta-ALA & protoporphyrin IX accumulate

29

bone crises, aseptic necrosis of the femur, hepatosplenomegaly, macrophages that look like "crumpled tissue paper"

Gaucher's disease
-most common lysosomal storage dz
-Glucocerebroside accumulates

30

hepatosplenomegaly, cherry red macula, foam cells

Niemann- Pick disease
- Sphingomyelin accumulates

"No Man Picks his nose w/ his Sphinger"

31

deficient enzyme in Tay Sachs disease

-lacking Hexosaminidase A

(GM2 Ganglioside accumulates)

32

deficient Beta-galactocerebrosidase

Krabbe's disease

-peripheral neuropathy
-optic atrophy

33

deficient alpha-L-iduronidase--> developmental delay, corneal clouding, hepatosplenomegaly

Hurler's syndrome

-heparin & dermatin sulfate accumulate

34

deficient Iduronate sulfatase --> aggressive behavior, NO corneal clouding, X-linked recessive

Hunter's syndrome

-milder than Hurler's
-"Hunters see clearly (no cataracts) and aim for the "X" (X- linked recessive)

35

this enzyme esterifies cholesterol

LCAT

36

delivers dietary triglycerides to tissues

Chylomicrons (intestines --> lymph --> blood --> tissues)

37

delivers hepatic triglycerides to tissues, secreted by the liver

VLDL

38

also delivers hepatic trigs to tissues, but this is converted from VLDL by LPL

LDL

-has apo B-100
-(VLDL --- lipoprotein lipase ---> LDL)

39

cofactor for Carboxylation reactions

ie: Pyruvate carboxylase...

BIOTIN

40

deficiency causes night blindness and dry skin

Vitamin A

41

microdeletion on long arm of chromosome 7, "elfin faces", very friendly with all people , well developed vocabulary

Williams syndrome

42

microdeletion on short arm chromosome 5, associated with VSD, severe MR

Cri du Chat syndrome

43

not able to add mannose-6-phosphate to proteins, lysosomal enzymes accumulate outside the cells...clouded corneas, coarse facies, restricted joint movement...

I-cell disease

(lysosomal storage dz)

44

more serious disorder of fructose metabolism, F-1-P accumulates/ trapped in cells, causes hypoglycemia

Aldolase B deficiency ("Fructose Intolerance")

45

amino acid needed for porphyrin & heme synthesis

Glycine (also need B6)

46

5 cofactors required for Pyruvate DH, Alpha-ketoglutarate DH & Branched chain-alphaketo acid DH

"TLC For Nancy"

-Thiamine
-Lipoate
-Coenzyme A
-FAD
-NAD+