Biochem - Block 3 - Part 2

davidwurbel7's version from 2015-04-19 08:42

LDL Receptor

Question Answer
LDL receptor has ___ domains5 Domains
Domain 1Ligand-Binding Domain
Domain 2EGF Precursor Homology Domain
Domain 3O-linked Sugar Domain
Domain 4Membrane-Spanning Domain
Domain 5Cytoplasmic Domain
Ligand-Binding DomainDomain 1
EGF Precursor Homology DomainDomain 2
O-linked Sugar DomainDomain 3
Membrane-Spanning DomainDomain 4
Cytoplasmic DomainDomain 5

Fatty Acid Oxidation

Question Answer
Glucagon and epinephrine activatesHormone Sensitive Lipase
Acts on monoacylglycerol to release fatty acids and glycerolMonoacylglycerol Lipase
Glycerol enters intoGluconeogenesis
Fatty Acids enters into the mitochondria forOxidation
The carrier of fatty acids released from adipose tissue into the bloodAlbumin
Present over outer mitochondrial membrane, activates fatty acid by adding CoAAcyl CoA Synthetase
Also present over the outer mitochondrial membrane, enzyme that transfers long-chain fatty acyl groups from CoA to carnitine to make fatty acyl-carnitineCarnitine Acyl Transferase I
Transports the fatty acyl-carnitine across inner mitochondrial membrane and carnitine into the intermembrane spaceCarnitine Acylcarnitine Translocase
Enzyme that catalyzes the conversion of fatty-acyl-carnitine back to fatty acyl CoA and carnitineCarnitine Acyl Transferase II

Beta Oxidation

Question Answer
Fatty acyl CoA is cleaved to produce FADH + H+Acyl CoA Dehydrogenase
The first reaction of Beta Oxidation requires which vitaminRiboflavin
The third reaction of Beta Oxidation requires which vitaminNiacin
The fourth reaction of Beta Oxidation requires which vitaminPantothenic Acid
The number of ATPs produced by one round of Beta Oxidation17
The number of ATPs produced by the final round of Beta Oxidation of an even-number carbon Fatty Acid17 + 12
In odd-number Fatty Acid, the final round of Beta Oxidation produces acetyl CoA and _______Propionyl CoA

VLC Fatty Acid and Branched Chain Fatty Acid Oxidation

Question Answer
Degradation of ceruloplasmagin, VLCFA, BCFA and ferritin releasing components for plasminogen and bile acids occurs herePeroxisome
Branched chain fatty acids first undergo ________ because the beta carbon is occupied by a methyl groupAlpha Oxidation
This fatty acid under go alternating alpha-beta oxidation in the peroxisome until the C8 when it moves to the mitochondriaBranched


Question Answer
In well fed state, keeps acetyl CoA carboxylase active and increases malonyl CoAInsulin
During fasting and starvation: Causes lipolysis and increase in free fatty acids (acyl CoA) which inhibits acetyl CoA carboxylase and decreases malonyl CoAGlucagon
The concentration of __________ regulates whether fatty acid synthesis occurs or whether beta-oxidation occursMalonyl CoA

Ketogenesis and Ketolysis

Question Answer
Precursor for all three ketone bodiesAcetyl CoA
HMG CoA is lysed by HMG CoA lyase producing acetyl CoA and the first ketoneAcetoacetate
Acetoacetate will also undergo spontaneous decarboxylation to form volatile compound which is exhaledAcetone
Acetoacetate undergo oxidation to form beta (3)-hydroxybutyrate catalyzed by beta (3)-hydroxybutyrate dehydrogenase, in this process there is consumption ofNADH + H+
Formation of beta (3)-hydroxybutyrate is favored because of high levels ofNADH + H+
The rate limiting enzyme isBeta (3)-hydroxybutyrate Dehydrogenase
Utilization of ketone bodies by the tissues requires the activity of the enzymeThiophorase (CoA Transferase/Acetoacetate:Succinyl CoA CoA Transferase)
The liver cannot use ketone bodies because it does not containThiophorase (CoA Transferase/Acetoacetate:Succinyl CoA CoA Transferase)
Transfers of CoA from succinyl CoA to activate acetoacetate to produce acetoacetyl CoAThiophorase (CoA Transferase/Acetoacetate:Succinyl CoA CoA Transferase)
Oxidation of beta (3)-hydroxybutyrate produces 1 NADH + H+ and 2 acetyl CoA yield27 - 1 ATP = 26 ATP

Glycerophopholipids and Sphingophopholipids

Question Answer
Ceramide plus a monosaccharideCerebroside
Ceramide plus a di-, tri- or tetrasacccharideGloboside
Ceramide plus a oligosaccharide plus N-acetyl neuraminic acid (NANA)Ganglioside
On electrogel, _____ moves the furthest on the gelGM3
On electrogel, _____ moves the least on the gelGM1


Question Answer
Pepsinogen is activated to its active form pepsin in the presence of acid (HCl) by this processAutocatalytic Activation
Trypsinogen is cleaved into its active form trypsin byEnteropetidase (Enterokinase)
Catalyzes the conversion of chymotrypsinogen to chymotrypsin, proelastase to elastase, and the procarboxypeptidases to the carboxypeptidasesTrypsin
Enteropetidase (Enterokinase) is secreted by _________ in the small intestineBrush Border Cells
Enzyme that acts on the carboxyl side of aromatic amino acids and positive-charged amino acidsPepsin
Endopeptidase enzyme that acts on carboxyl side of hydrophobic amino acidsChymotrysin
Exopeptidase enzyme that acts on carboxyl side of hydrophobic amino acidsCarboxypeptidase A
Exopeptidase enzyme that acts on carboxyl side of positive-charged amino acidsCarboxypeptidase B
Endopeptidase enzyme that acts on the carboxyl side of small-chain amino acidsElastase
Endopeptidase enzyme that acts on the carboxyl side of lysine and arginineTrypsin
In the intestine and kidney, amino acids can be transported across the cell membrane byγ-Glutamyl Cycle
Transfers amino group from aspartateAspartate Transaminase (AST)
Transfers amino group from alanineAlanine Transaminase (ALT)
All amino acids except for Lysine and Threonine can undergoTransamination Reaction
The conversion of an amino acid and an α-keto acid into another amino acid and α-keto acidTransamination Reaction
In a transamination reaction, the carbon skeleton for the second amino acid comes fromα-Keto Acid 1
In a transamination reaction, the amino group for the second amino acid comes fromAmino Acid 1
In a transamination reaction, the carbon skeleton for the second α-keto acid comes from Amino Acid 1
α-Ketoglutarate is converted into glutamate or the reverse if concentrations of glutamate is high in all Transamination Reaction
This coenzyme is required for transamination reactions to occurPyridoxal Phosphate (PLP)
Pyridoxal phosphate is derived fromPyridoxine (Vitamin B6)
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