Biochem - Final - Part 4

davidwurbel7's version from 2015-04-20 01:00

Protein (Continued)

Question Answer
α-Ketoglutarate is converted into glutamate using ammonium ion by the enzymeGlutamate Dehydrogenase
Enzyme that can use either NAD+ or NADP+ as a coenzymeGlutamate Dehydrogenase
One of the three mammalian enzymes that can “fix” NH4+ into organic moleculesGlutamine Synthetase
One of the three mammalian enzymes that can “fix” NH4+ into organic moleculesCarbamoyl Phosphate Synthetase I
One of the three mammalian enzymes that can “fix” NH4+ into organic moleculesGlutamate Dehydrogenase
The nitrogen of aspartate and free ammonium ion combine in the liver to formUrea
During fasting conditions, the break down of muscle is exporting, primarily _________ into the blood and picked up by the liver to be used in gluconeogenesisAlanine
Alanine and glutamine are the primary carriers of __________ in the bloodNitrogen
Rate limiting enzyme for urea cycleCarbamoyl Phosphate Synthetase I
N-acetylglutamate positively regulatesCarbamoyl Phosphate Synthetase I
The nitrogen in carbamoyl phosphate comes fromAmmonium
The carbon backbone in carbamoyl phosphate comes fromBicarbonate
The phosphate in carbamoyl phosphate comes fromATP
Enzyme for fixing ammonia to bicarbonate using ATPCarbamoyl Phosphate Synthetase I
Carbamoyl phosphate reacts with ornithine to form citrullineOrnithine Transcarbamoylase
Citrulline reacts with aspartate using 2 ATP to form argininosuccinateArgininosuccinate Synthetase
Argininosuccinate is cleaved by to form fumarate and arginine Argininosuccinate Lyase
The fate of fumarateKrebs Bicycle
Arginine is cleave using water producing urea and regenerating ornithineArginase
Arginine is cleaved using water by arginase which regenerates ornithine and producesUrea
Allosteric activation of carbamoyl phosphate synthetase I leading to positive regulationN-Acetylglutamate (NAG)
How many glucose molecules are formed from two alanine1
How many urea molecules are formed from two alanine1
The ratio of ammonium ion to ammonia100:1

Protein Metabolism

Question Answer
The rate limiting step in the synthesis of these neurotransmitters derived from L-tyrosine is catalyzed byTyrosine Hydroxylase
Tyrosine hydroxylase requires ________ as a coenzymeBH4
L-Tyrosine is converted to L-Dopa byTyrosine Hydroxylase
L-Dopa is converyed to Dopamine byDopa Decarboxylase
Dopa Decarboxlase requires _________ as a coenzymePyridoxal Phosphate (PLP)
Dopamine Is converted to Norepinephrine byDopamine β-Oxidase
Dopamine β-Oxidase requires _______ as a cofactorCopper
Dopamine β-Oxidase requires _______ as a coenzymeAscorbate
Dopamine is catabolized intoHomovanillic Acid
Epinephrine and norepinephrine are catabolized intoVanillylmandelic Acid
Tryptophan undergo hydroxylation reaction by tryptophan hydroxylase to form5-Hydroxytryptophan
Tryptophan hydroylase requires ________ as a coenzymeBH4
5-hydroxytryptophan undergo decarboxylation reaction to formSerotonin
Serotonin is converted toMelatonin
L-tryptophan can undergo dioxygenase catalyzed reaction to form kynurenine and then to quinolinate which will formNiacin
60 mg of tryptophan is equal to 1 mg ofNiacin
Norepinephrine is converted to epinephrine byPhenylethanolamine N-Methyltransferase
In melanocytes, _______ converts tyrosine to dopa and then dopa to dopaquinone. The dopaquinone is then converted into either pheomelanins or eumelaninsMelanocyte Copper Dependent Tyrosinase
Melanocyte Copper Dependent Tyrosinase requires __________ as a cofactorCopper
5-Hydroxytryptophan is converted to serotonin byDopa Decarboxylase
Histamine is synthesized from histidine byHistidine Decarboxylase
Histidine Decarboxylase requires __________ as a coenzymePyridoxal Phosphate (PLP)
GABA is synthesized in neurons from glutamate byGlutamic Acid Decarboxylase (GAD)
Glutamic acid decarboxylase requires ________ as a coenzyme Pyridoxal Phosphate (PLP)

Amino Acid Metabolism

Question Answer
Deficiency of B12 or defect in methionine synthase would lead to accumulation of N5-methyl-THF and hence THF would be trapped as N5-mtheyl-THF leading to functional folate deficiencyFolate Trap
Converts homocysteine to cystathionine by combining homocysteine with serineCystathionine β-Synthase
Cystathionine β-synthase requires __________ as coenzymePyridoxal Phosphate (PLP)
Cleaves cystathionine to release cysteine and α-ketobutyrateCystathionase
Cystathionase requires _________ as coenzymePyridoxal Phosphate (PLP)
α-Ketobutyrate is eventually converted in which TCA cycle intermediateSuccinyl CoA
Cystathionine β-synthase is negatively feedback byCysteine
The reactions of norepinephrine to epinephrine; guanidinoacetate to creatine; nucleotides to methylated nucleotides; phosphatidylethanolamine to phosphatidylcholine; acetylserotonin to melatonin all require _____________ as a methyl group donorS-adenosylmethionine (SAM)
Branch chain amino acid that is only gluconeogenicValine
Branch chain amino acid that is gluconeogenic and ketogenicIsoleucine
Branch chain amino acid that is only ketogenicLeucine
A derivative of arginine, glycine and SAM, is found in muscleCreatine Phosphate
Arginine condense with glycine to formGuanidoacetic Acid
Guanidoacetic acid condensation occurs in which organKidney
Guanidoacetate is methylated to formCreatine
Guanidoacetate is methylated to form creatine in which organLiver
Creatine is phosphorylated to ______ by creatine kinaseCreatine Phosphate
Creatine is phosphorylated to creatine phosphate in which organMuscle
Creatine and creatine phosphate degrades intoCreatinine

Purine/Pyrimidine Metabolism

Question Answer
In purine ring, N1 is fromAspartate
In purine ring, C2 and C8 are fromN10-Formyl-Tetrahydrofolate
In purine ring, N3 and N9 are fromGlutamine
In purine ring, C4, C5, and N7 are fromGlycine
In purine ring, C6 is fromCarbon Dioxide
In purine synthesis, _______ is attached to the N9Ribophosphate
Consisting of 13 reactions and requiring 7 molecules of ATP for every mononucleotide synthesizedPurine Synthesis
The rate limiting enzyme of purine synthesisPRPP Glutamyl Amidotransferase
In synthesis of AMP, the enzyme that requires GTP and Mg+2Adenylosuccinate Synthase
In synthesis of GMP, the enzyme that requires ATPTransamidinase
The formation of deoxynucleotides is catalyzed byRibonucleotide Reductase Complex
Ribonucleotide Reductase Complex is positively modulated byATP
Ribonucleotide Reductase Complex is negatively modulated bydATP
This enzyme is inhibited by GMP, GDP, GTP, AMP, ADP and ATPGlutamine Phosphoribosyl Amidotransferase
This enzyme is inhibited by GDP and ADPPRPP Glutamyl Amidotransferase
This enzyme is inhibited by GMPIMP Dehydrogenase
This enzyme is inhibited by AMPAdenylosuccinate Synthetase
Adenine is converted to AMP using PRPPAdenine Phosphoribosyl Transferase (APRT)
Hypoxanthine is converted to IMP using PRPPHypoxanthine-Guanine Phosphoribosyl Transferase (HGPRT)
Guanine is converted to GMP using PRPPHypoxanthine-Guanine Phosphoribosyl Transferase (HGPRT)
Adenosine is first converted to inosineAdenosine Deaminase
Guanosine and inosine are converted to hypoxanthine and guanine catalyzedPurine Nucleoside Phosphorylase
Guanine and hypoxanthine are converted to xanthine and then to uric acidXanthine Oxidase
Xanthine oxidase requires this metal ion as a cofactorMolybdenum
In pyrimidine ring, N1, C4, C5, C6 are fromAspartate
In pyrimidine ring, N3 is fromGlutamine
In pyrimidine ring, C2 is fromCarbon Dioxide
The regulated enzyme of pyrimidine synthesisCarbamoyl Phosphate Synthetase II
Carbamoyl phosphate sythetase II is positively modulatedPRPP and ATP
Carbamoyl phosphate sythetase II is negatively modulatedUTP
The rate limiting enzyme of pyrimidine synthesis forming carbamoylaspartate.Aspartate Transcarbamoylase
The committed step of pyrimidine synthesis is the formation ofCarbamoylaspartate
dUMP undergo methylation to form dTMPThymidylate Synthase
Thymidylate synthase requires _______________ as the methyl group donorN5,N10-Methylene-Tetrahydrofolate
The end products are highly water-soluble products which are CO2, NH3, β-alanine, and β-aminoisobutyratePyrimidine Catabolism


Question Answer
Vitamins C and B complexesWater Soluble Vitamins
Vitamins A, D, E and KFat Soluble Vitamins
Predominantly eating polished riceThiamine deficiency
Chronic alcoholismThiamine deficiency
VegansCobalamin deficiency
Fat MalabsorbationVitamin A, D, E and K deficiency
Pyruvate dehydrogenase complex requires this vitaminThiamine
Alpha-ketoglutarate dehydrogenase complex requires this vitaminThiamine
Branched chain-alpha-ketoacid dehydrogenase complex requires this vitaminThiamine
Transketolase reaction in pentose phosphate pathway requires this vitaminThiamine
Biologically active forms are flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD)Riboflavin
Component of electron transport chain complexesRiboflavin
Important for the metabolism of fat, carbohydrates, proteins. Riboflavin
Plays a role in drug and steroid metabolism, including detoxification reactionsRiboflavin
Reversibly accepts hydrogen atoms to become reduced to FADH2 and FMNH2Riboflavin
Extremely light sensitiveRiboflavin
NAD(H) dehydrogenases catalyze oxidative pathways Niacin
NADP(H) reductases catalyze reductive biosynthesisNiacin
Tryptophan can be converted to this vitamin with an efficiency of 60:1 by weightNiacin
Component of coenzyme A (CoA) which transfers acyl groups.Pantothenic acid
Biologically active form is pyridoxal phosphate (PLP).Pyridoxine
Acts as a coenzyme for all carboxylases; carrier of CO2 in the carboxylase catalyzed reaction also requires ATP and Mg2+Biotin
Rapidly absorbed from intestine, not significantly stored, excreted as diketogulonic acid and oxalic acid.Ascorbic acid
Biologically active forms dehydroascorbic acid and ascorbateAscorbic acid
Smoking, hemodialysis, pregnancy, and stress increase requirementAscorbic acid
Coenzyme for prolyl hydroxylase and lysyl hydroxylaseAscorbic acid
Coenzyme for dopamine beta-hydroxylaseAscorbic acid
Participates in carnitine biosynthesisAscorbic acid
Are converted to 5-methyl tetrahydrofolate (THF) within the small intestinal mucosa before entering portal plasmaFolic acid
Acts as coenzymes in the transfer of single carbon unitsFolic acid
Involved in purine biosynthesisFolic acid
involved in the conversion of homocysteine to methionineFolic acid
Causes for deficiency include pregnancy, poor intestinal absorption, chronic alcoholism, cvercooking of green leafy vegetables, treatment with methotrexateFolic acid
Requires R-binder and intrinsic factor (IF) for absorption and absorbed in the last distal IleumCobalamin
Deficiency is usually due to malabsorption and protental to arises in vegansCobalamin
Atrophic gastritis with pernicious anemia, congenital IF deficiency, gastrectomy, food malabsorption, intestinal malabsorption, abnormalities in metabolismCobalamin
Intestinal causes of malabsorption: e.g. ileal resection, tropical sprue, celiac disease, small bowel bacterial over growth syndrome, fish tape worm infestationCobalamin
Abnormalities of metabolism: congenital transcobalamin II deficiency, nitrous oxide inhalationCobalamin
β-carotene is a precursor ofRetinol
Loaded on to APO B48, secreted as chylomicronsRetinol
Binds with opsin producing neuronal signal in the eyeRetinol
Component of the visual pigment in photoreceptor of rod cells., maintains bone development and growth in children, essential for normal reproduction; male spermatogenesis, fetal development in females and essential for normal differentiation of epithelial tissues and mucus secretionRetinol
The skin can produce this vitamin when exposed to UVB lightCholecalciferol
Hydroxylated at its 25th carbon in the liver by 25-hydroxylaseCholecalciferol
Hydroxylated at its 1st carbon in the kidneys by 25(OH)D3-1α-hydroxylaseCholecalciferol
Important naturally occurring antioxidants, stored in fat deposits, accumulate on cell membranes and transported through VLDL.Tocopherol
Prevents oxidation of LDL and play an important role in reducing the risk of cardiovascular disease.Tocopherol
Plays a role in cellular respiration by stabilizing ubiquinone.Tocopherol
Required for the posttranslational carboxylation of glutamic acidMenaquinone
Newborns are susceptible to Hemorrhagic disease of newborn because of a deficiency ofMenaquinone