Biochem - Final - Part 1

davidwurbel7's version from 2015-04-19 19:06

Heme Synthesis

Question Answer
Heme precursor containing acetate and proprionate arranged in P A P A pattern around the ringUroporphyrin
Heme precursor containing proprionate and methyl arranged in P M P M pattern around the ringCoproporphyrin
Heme precursor containing proprionate, methyl and vinyl arranged in P M V M V M P M pattern around the ringPhotoporphyrin
Synthesized from simple precursors glycine and succinyl CoAHeme
Committed and rate limiting step in heme synthesisδ-Aminolevulinic Acid (δ-ALA) Synthase
δ-ALA synthase requires ___________ as coenzyme Pyridoxal Phosphate (PLP)
Erythroid tissue produces only ___________ from a gene for which is located on X chromosomeALAS2
All other cells produce _________ for heme synthesisALAS1
ALAS2 is controlled by the availability ofIntracellular Iron
The enzyme, ALAS1, is feed back inhibited byHeme
When heme accumulates, it is converted to ________ by the oxidation of Fe2+ to Fe3+Hemin
Two molecules of δ-ALA condense to form the pyrrole, porphobilinogen by the enzymeδ-ALA Dehydratase (Porphobilinogen (PBG) Synthase)
δ-ALA dehydratase or PBG synthase contains what metal ionZinc
Four porphyrinogens condense to form a linear chains containing acetyl (A) and propionyl (P) groupsPorphobilinogen Deaminase (HMB synthase)
Catalyzes the flipping of acetate and propionyl groups at the fourth ringUroporphyrinogen III Cosynthase
Catalyzes the decarboxylation of all of the acetate (A) to methyl (M) groupsUroporphyrinogen Decarboxylase
Catalyzes the decarboxylation and oxidation of propionate (P) groups on first and second ring to acetate (A) groups to make protoporphyrinogen IXCoproporphyrinogen Oxidase
Oxidation of protoporphyrinogen to protoporphyrin is catalyzed byProtoporphyrinogen Oxidase
Incorporation of ferrous iron into protoporphyrin is catalyzed byFerrochelatase
In lead toxicity, zinc released from delta-ALA dehydratase binds with Protoporphyrin IX results in increased blood levelsZinc-Protoporphyrin
In lead toxicity, ______ will be increased in the blood, and hence decrease in hemoglobin synthesisδ-ALA
Heme synthesis reactions 1, 6, 7 and 8 occur in theMitochondria
Heme synthesis reactions 2, 3, 4 and 5 occur in theCytoplasm

Regulation of Heme Synthesis

Question Answer
Heme inhibits activity of pre-existing δ-ALA Synthase 1.
Heme diminishes the transport after its synthesis in cytoplasm from cytoplasm to mitochondria.δ-ALA Synthase
Heme represses the production of ________ by regulating gene transcription.δ-ALA Synthase
Heme represses the production of δ-ALA synthase by regulatingGene Transcription
Heme stimulate synthesis of globin atGene Level.
Inhibition of __________ and stimulation of ________keeps hemoglobin synthesis in balance.δ-ALA Synthase, Globin Synthesis

Measurement of Bilirubin

Question Answer
Uses diazotized sulfanilic acidVan den Berg Reaction
Conjugated bilirubin, water soluble, react with sulfanilic acid to form dipyrrylmethene azopigmentDirect Reaction
Ethanol releases albumin bound bilirubin (unconjugated bilirubin), now both conjugated and unconjugated bilirubin react with sulfanilic acidTotal Bilirubin
Total bilirubin – direct bilirubinUnconjugated Bilirubin


Question Answer
Average dietary intake level that is sufficient to meet the nutrient requirement of nearly all (97-98%) the individuals in a life stage and gender group.Recommended dietary allowance (RDA)
Average daily nutrient intake level estimated to meet the requirement of one half of the healthy individuals in a particular life stage and gender group.Estimated average requirement (EAR)
When sufficient scientific evidence is not available to calculate EAR or RDA, the AI is based on estimates of nutrient intake by a group of apparently healthy people that are assumed to be adequate.Adequate intake (AI)
The highest average daily intake level that is likely to pose no adverse health effects to almost all individuals in the general population.Tolerable upper intake level (UL)
Average dietary energy intake predicted to maintain an energy balanceEstimated energy requirement
30 kcal/kg/day to maintain body weight.Sedentary adults
35 kcal/kg/day to maintain body weight.Moderately active adult:
40 kcal/kg/day to maintain body weight.Very active adult
Energy value of carbohydrate4 kcal/g
Energy value of protein4 kcal/g
Energy value of fat9 kcal/g
Energy value of alcohol (ethanol)7 kcal/g
Energy required to carry out the normal body functionsBasal Metabolic Rate (BMR)
Diet-induced thermogenesis, 3-10% of total energy expenditure.Thermic effect of food
Muscular activity provides the greatest variation in energy expenditure.Physical Activity
Forms viscous gel when mixed with a liquidSoluble Fiber
Passes through the digestive tract largely intactInsoluble Fiber
RDA for protein computed for proteins of mixed biological value is0.8 g/kg/day for adults

Diabetes Mellitus

Question Answer
Caused by beta-cell destructionType 1 DM
Caused by insulin resistanceType 2 DM
Mutation in pancreatic glucokinaseMODY Type II
Due to pregnancyGestational Diabetes Mellitus (GDM)
Fasting Plasma Glucose (FPG) level≥ 126 mg/dL
Two-hour plasma glucose (PG) ≥ 200 mg/dL
Level of HbA1c≥ 6.5%
Patient exhibiting polyuria, polyphagia, polydipsiaDiabetes Millitus
At risk Fasting Plasma Glucose (FPG) level100 - 125 mg/dL
At risk Two-hour plasma glucose (PG) ≥ 140 mg/dL
At risk Level of HbA1c≥ 5.7 - 6.4%
Cortisol induces the formation of epinephrine from norepinephrine by inducing the enzyme ________ which converts norepinephrine into epinephrinePhenylethanolamine N-Methyltransferase
Most common cause of insulin resistanceObesity

Medications and Treatments

Question Answer
Significantly increases ALAS1 activityBarbiturates
Cytochrome P450 metabolize ___________ increasing the need for hemeBarbiturates
Decreases the activity of hepatic ALAS1 by acting at various levelsHemin
Treatment for porphyriasHemin and Glucose
Increases UDPGT activityPhenobarbital
Orthotopic liver transplantation is only treatmentCrigler-Najjar Syndrome Type 1
Treatment for Crigler-Najjar syndrome type 2Phenobarbital
Treatment for physiological jaundice of the newbornPhototherapy-UV Light (blue light)