Biochem yay... Flashcards
a Pyruvate DH deficiency will lead to build up of __________
Lactic acid
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
If delta G is negative:
the reaction favors the products and Keq > 1
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
diseases of mitochondrial DNA are passed from ______ to ________
mother to all of her offspring
deletion or insertion of 1 nucleotide is a __________ mutation
Frameshift (any deletion or insertion NOT in multiples of 3)
a single base substitution that causes the codon & the amino acid to change
Missense mutation
pt with large amounts of orotic acid in the urine— you should supplement them with _______
Uridine –improves symptoms by inhibiting CPS II enzyme
Nitric oxide synthase (eNOS) synthesizes NO from which amino acid??
L- Arginine
mechanism of Streptomycin
binds 30s ribosomal subunit & impairs INITIATION of translation
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
bacterial mRNA can be polycistronic…meaning _____________
one mRNA codes for several proteins
liver glycogen stores usually become depleted after _________ hours of fasting
12-18 hours
-after that gluconeogenesis is the main way to maintain blood glucose
________ is a glucose sensor in beta cells, inactivating mutations of this enzyme result in mild hyperglycemia that can be made worse in pregnancy
Glucokinase
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)
What 4 enzymes need Thiamine (B1) to function?
1) Pyruvate DH
2) a-ketoglutarate DH
3) Transketolase
4) branched chain alpha-ketoacid DH
Which TCA cycle enzyme uses FAD (from Riboflavin (B2)) ??
Succinate DH (converts Succinate to Fumarate)
-uses FAD –> makes FADH2
Which autoantibody has the highest specificity for RA?
Anti-CCP (cyclic citrullinated peptide)
-ANA & RF are not very specific
Which B vitamin is needed for transamination reactions?
B6 (Pyridoxine)
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)
Which amino acid becomes essential in a baby with PKU?
Tyrosine
deficiencies of vitamins ___, ____, & ___ are associated with high levels of homocysteine
(which is associated with thrombosis/ atherosclerosis)
B6, B12, & Folate
Where in the cell do 5’ capping, poly-A tail addition, & intron splicing happen?
Nucleus
chronic vitamin A toxicity (overuse) symptoms
alopecia, dry skin, hyperlipidemia, hepatosplenomegaly, liver damage, vision changes / papilledema
this mineral activates many enzymes
Calcium
______ are made by RNA pol II in the nucleus, help remove introns from the RNA & thus are necessary for making mRNA
snRNPs
the Nitrogen atoms in Urea are derived from ___ & ____
NH3 & Aspartate
note: CPS I is the RLS in the urea cycle
Lead blocks ___________ in the heme biosynthetic pathway
ALA dehydratase (delta -Aminolevulinate DH)
-thus in Lead poisoning, delta-ALA & protoporphyrin IX accumulate
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
hepatosplenomegaly, cherry red macula, foam cells
Niemann- Pick disease
- Sphingomyelin accumulates
“No Man Picks his nose w/ his Sphinger”
deficient enzyme in Tay Sachs disease
-lacking Hexosaminidase A
GM2 Ganglioside accumulates
deficient Beta-galactocerebrosidase
Krabbe’s disease
- peripheral neuropathy
- optic atrophy
deficient alpha-L-iduronidase–> developmental delay, corneal clouding, hepatosplenomegaly
Hurler’s syndrome
-heparin & dermatin sulfate accumulate
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)
this enzyme esterifies cholesterol
LCAT
delivers dietary triglycerides to tissues
Chylomicrons (intestines –> lymph –> blood –> tissues)
delivers hepatic triglycerides to tissues, secreted by the liver
VLDL
also delivers hepatic trigs to tissues, but this is converted from VLDL by LPL
LDL
- has apo B-100
- (VLDL — lipoprotein lipase —> LDL)
cofactor for Carboxylation reactions
ie: Pyruvate carboxylase…
BIOTIN
deficiency causes night blindness and dry skin
Vitamin A
microdeletion on long arm of chromosome 7, “elfin faces”, very friendly with all people , well developed vocabulary
Williams syndrome
microdeletion on short arm chromosome 5, associated with VSD, severe MR
Cri du Chat syndrome
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
more serious disorder of fructose metabolism, F-1-P accumulates/ trapped in cells, causes hypoglycemia
Aldolase B deficiency (“Fructose Intolerance”)
amino acid needed for porphyrin & heme synthesis
Glycine (also need B6)
5 cofactors required for Pyruvate DH, Alpha-ketoglutarate DH & Branched chain-alphaketo acid DH
“TLC For Nancy”
- Thiamine
- Lipoate
- Coenzyme A
- FAD
- NAD+
