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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


Prokaryotic polymerases?

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


Eukaryotic polymerases?

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)

4 steps
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?

GTP and

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
Wiskot Aldrich
Ocular albinism
Lesch Nyhan
Duchenne (and Becker)
Hunter Syndrome
Hemophilia A and B
Ornithine transcarbomylase def


Angelman is what genetically?

MAMA Maternal gene Angelman Mood (inappropriate laugh) Ataxia

chromosome 15

happy puppet


What metastasizes to the brain? mnemonic alert

Lots of Bad Stuff Kills Glia

Skin (melanoma)
Kidney (RCC)


Hexokinase vs glucokinase? locaiton?



Insulin induction?

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?



Pyruvate kinase


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
RBC proteciton


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?

Cholesterol synthesis?

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


Mnemonic for lead poisoning presentation?


Mental retardation

Lead Lines on gingival or metaphase of long bones
Encephlaopathy and erythrocyte basophilic stippling
Abdominal colic and sideroblastic Anemia
Drops of wrist and foot and Dimeraprola dn efta are first line treatment

Succimer is used for chelation in kids b/c SUCks to be kid who eats lead