Flashcards in DIT Biochem 1 Deck (43):
What 5substance are going into purines? What donates what?
And what go into pyrimadines?
Glycine (C), Glutamine (N), Aspartate (N), CO2 (C) and tetrahydrofolate (C)
Pyr: Aspartate, carbamoyl phosphate (CO2 and glutamine and ATP make up carbamoyl phosphate)
What enzyme is rate limiting step of pyrimidine synthesis?
Carbamoyl phosphate synthetase II takes Glut and CO2 and 2 ATP to make carbamoyl phosphate
What does 5 FU block?
Thymidylate synthase (the enzyme to make dTMP from dUMP, the same one that needs THF)
Baby with failure to thrive, megaloblastic anemia, hyper segmented neutrophil, that can't be cured with folate or B12 and no hyperammonemia? Tx?
Orotic aciduria is unable to make orotic acid into UMP.
Tx is UMP to bypass enzyme mutation
DNA polym III is for making a leading strand and lagging strand
DNA polym I is to replace RNA primers
DNA ligase closes the last bit up
DNA polym alpha needs no primers and is for lagging strands
DNA polym Delta is on leaDing strand
DNA polym Beta is Broken DNA repair
DNA polym gamma is for mitochondria
What type of DNA damage is repaired in nucleotide excision repair?
What if deficient?
Nucleotide Excision repair
Dimers cause kink in DNA
Endonuclease remove nucleotide
DNA polym inserts new nucleotide
DNA ligase closes it up
Xeroderma pigmentosa is deficiency and dimers happen from ultraviolet light
What type of damage is fixed with base excision repair?
Remove damaged base (apurine or apyrimadine site)
Glycosolase removes damaged base
Endonuclase cuts DNA and removes sugar
DNA poly puts in new nucleotide
DNA ligase closes it up
(last three steps are just like nucleotide excision repair)
NEEDED to repair from toxic damage
What DNA repair is for fixing damaging to both strands?
Damage to this causes what?
Nonhomologu end joining problem causers ataxia telangiectasia
IgA deficiency, cerebellar ataxia, high AFP after 8 months of age. SENSITIVE to ionizing radiation (The A disease on page 213 FA)
Explain lac operon
There is a CAP which is to activate and a lac repressor. Each binds their metabolite and if no glucose (CAP is bound to DNA) and lactose is present (lactose metab binds repressor so it can't bind DNA) and operon is on!
Where does aminoacylt tRNA synthetase work?
3' end of tRNA to load it at the CCA
What allows for a tRNA to come in and bind to A site of 40s subunit in eukaryotes? and in prokaryotes?
Euckaryotes: Elongation Factor 2 (diphtheria and exotoxin A in pseudomonas)
Prokaryotes is elongation factor G
What makes collagen and fibrillin and elastin?
fibroblasts (fibrous support network proteins)
Mnemonic for X recessive?
Be Wise Fools GOLD Heeds Silly Hope
Brutons X linked aggamagl
Duchenne (and Becker)
Hemophilia A and B
Ornithine transcarbomylase def
Angelman is what genetically?
MAMA Maternal gene Angelman Mood (inappropriate laugh) Ataxia
What metastasizes to the brain? mnemonic alert
Lots of Bad Stuff Kills Glia
Hexokinase vs glucokinase? locaiton?
Feedback inhib by Gluc6P?
Associated with MODY?
Glucokinase in glucose controlling tissue
G has higher Km (needs a lot of, duh, b/c don't want liver to hog all the glucose)
G has high Vm (duh, if there is a ton of sugar, do something with it)
G is insulin induction, duh
G is inhibited b/c you don't want to waste effort
G is associated with maturity onset diabetes of the young MODY
3 enzymes of glycolysis you need to know?
Hemoliytic anemia due to problem in glycolysis?
Pyruvate kinase issue b/c can't do efficient glycolsyis and Na/KATPase pumps fail and cells lyse
What does glucagon do with the phosphofructokinase stuff?
Glucagon activates adenylyl cyclase cAMP which activates PROTEIN KINASE A
that phosphorylates the PFK-2/FBP2 complex which deactivates phosphofructokianse 2 and activates fructose bisphopshphatase 2 which makes more fructose 6 phosphate for GLUCONEOGENEIS in times of low blood sugar
4 unique enzymes of gluconeogenesis? mnemonic
Pathway Produces Fresh Glucose
Pyruvate carboxylase (needs biotin)
PEP carboxykinase (makes PEP)
Fructose 1, 6 bisphosphatase RATE LIMITING
Glucose 6 phosphatase
Put down the deficiencies in each glycogen storage disease?
Very Poor Carb Metab
Von Gierke is glyc 6 phosphatase
Pompe is lysosomal alpha 1, 4 glucosidase
Cori is debranching 1,6 glucosidase
McArdie is muscle glycogen phosphorylase
What does arsenic block in pyruvate dehydrogenase complex?
How does arsenic present?
Inhibits lipoic acid
Presents as garlic breath nd gastroenteritis
Pyruvate dehydrogenase deficiency causes and tx?
Arsenic or deficient in the TLC For Nobody
Findings; lactic acidosis (b/c pyruvate shunt) and high alanine.
Give vitamines, penicillamine or dimercaprol if garlic breath, FATS and LYSINE and LEUCINE b/c KETOGENIC to make ketone bodies
Lysine and Leusine are onLy pureLy ketogenic amino acids
What carries nitrogen in blood?
Alanine and glutamine
What is NADPH used for?
Fatty acid and cholesterol synth
Oxygen free radical production
What is abetalipoproteinemia?
MTP gene so mutated apo B48 and B100 so not able to let fat leave enterocytes
Steatorrhea, ADEK, Night blindness, ACANTHOCYTES, Ataxia
Tx: Vit E helps make the lipoproteins again.
What is Apo E?
Apo E is Extra remnanat uptake.
E for Entrance!
What is Apo A-1
Apo A-1 is Activation of LCAT on HDL to take out cholesterol from cells
what is Apo C-II?
apo C-II is Cofactor for LIPOPROTEIN LIPASE (so needed to take in lipids)
What is Apo B-48 and B-100?
48 is for leaving enterocytes and 100 is for leaving liver (ALSO reuptake)
Deficiency is abetalipoptoeteinemia (a few flash cards earlier and handwritten notes onFA 118)
What is findings with Type I hyperchylomicronemia?
Cause of it?
AR. Liporptiein Lipase is deficient or ALTERED apolipoprotein C-II (Cofactor for LPL)
Pancreatitis (high tg_, heaptosplenomegaly, xanthomas.
NO INCREASED RISK FOR MI b/c not making plaques
Cause of Type IV hyper triglyceridemia?
Autosomal dominant over production of VLDL
Pancreatitis (triglycerides are high)
Rate limiting step for:
Fatty acid synth?
Fatty acid degrade?
Ketone body synth?
FA synth: Acetyl Coa Carboxylase
FA degrade: CARNitine acytyltransferase-1 (CARNAGE of FA)
Chol synth: HMG CoA Reductase
Ket B synth: HMG CoA synthetase
B6 is needed for tryptophan to be made into good products. What products come from tryptophan?
Niacin (deficiency is pellegra)
B6 is needed for histidine to become what?
B6 is needed for glycine to become what?
Porphyrin, which becomes heme (THERE IS A Y in glYcine and porphYrin)
B6 is needed for glutamate to become what?
GABA (if deficient you get seizures)
these start with G and have no y
What two enzymes do you need to know for urea cycle?
Carbamoyl phosphate synthetase I is in the mitochondria
Ornithine transcarbomilase also
What urea cycle genetic disorder is X linked? What are findings and tx?
Carbamoyl transferase deficiency:
High orotic acid (b/c carbamoyl phosphate is converted to it)
Low BUN (no urea made)
Hepatoencephalopathy with high NH3: slurred speech, somnolence, vomit, cerebral edema and blurred vision
What can arginine be broken down to?
Nitric Oxide (DUH)
What is high in the blood with maple syrup urine disease? What is the defect?
How do you treat?
I LoVe maple syrup. no Isoleucine Leucine or Valine
alpha ketozcid dehydrogenase problem so alpha ketoacids are in the blood