BIOCHEM EXAM 2

vitamin that plays a role in formation of prothrombin

K

enzyme used to decarboxylate Pyruvate to AcetylCoA

pyruvate dehydrogenase

In PPP, what phase generates 6-Phosphogluconate

Oxidative phase

Which isoform of creatine kinase is found in brain?

CPK-1

Oxidizes a substrate under anaerobic conditions

dehydrogenases

How many pyruvates are formed in a glycolysis reaction?

two

Oxidative decarboxylation of pyruvate forms...

acetylCoA

Xanthine oxidase is used for...

oxidation of purine

In PPP, what co-enzyme is used by transketolase?

Vitamin B1

Vitamin responsible for synthesis of blood clotting proteins

Vitamin K

Phosphagens act as a storage of high energy phosphate as...

creatine and arginine phosphate

Isoenzyme of LDH (LDH-4) found in liver will conduct conversion of...

lactate to pyruvate

erythrocyte hemolysis is impairment of what pathway?

Pentose Phosphate Pathway

Calcinosis is caused by excess intake of what vitamin?

D

Oligomycin is an inhibitor of what conversion?

as an inhibitor of ADP to ATP conversion

Type of reactions in PPP

two irreversible oxidative reactions followed by reversible non oxidative phase

Pyruvate kinase phosphate is an example of...

protein modification by covalent bond formation

example of homotropic allosterism

oxygen binding to the active sites in HbA cooperatively

cholesterol is synthesized where?

liver

reactions of PPP occur where?

cytosol

Deficiency of aldolase B

hypoglycemia

Osteomalacia is a deficiency of what vitamin?

D

Hemolytic anemia is deficiency of what enzyme?

Glucose-6-phosphate dehydrogenase

Production of D-Glucuronate in Uronic acid pathway

Glc-6-P...Glc-1-P...UDPGlc...D-Glucuronate

Type of enzyme that converts pyruvate to alanine

transaminase

Enzyme used to convert purine base to uric acid

Xanthine oxidase

High NADH/NAD+ ratio in glycolysis reaction

pyruvate to lactate

simvastatins and lovastatins are what kind of inhibitors?

competitive

In PPP, enzyme that acts between erythrose-4-P and Xylulose-5-P

transketolase

LDH1 favors what conversion?

lactate to pyruvate

product of anaerobic glycolysis in erythrocytes

lactate

suicide substrates bind to the ____ site via a _____ bond

active site, covalent bond

Genetic deficiency of what enzyme in PPP leads to hemolytic anemia?

Glucose-6-Phosphate dehydrogenase

secreted as a response to hypoglycemia and activates glycogenolysis and gluconeogenesis in liver causing it to release glucose in blood

glucagon

vitamin B6 is used as co-enzyme for transamination in aa in what reaction?

decarboxylation reactions

essential fructosuria is lack of which enzyme in the liver?

fructokinase

major pathway in the kidney

gluconeogenesis

AH + O2 + ZH2 = AOH + H2O + Z is catalyzed by...

monooxygenases

competitively inhibits succinate dehydrogenase

malonate

acts a poison for complex IV of oxidative phosphorylation

carbon monoxide

Phylloquinone belong to which type of vitamin?

K

Night blindness is a deficiency of what vitamin?

Retinol

Used in reductive synthesis of fatty acids, steroids, or in oxidative process of PPP

NADP+

AA not commonly found in active site of proteins

Asn

M4 found in muscle and liver is responsible for what conversion?

pyruvate to lactate

FAD and NAD+ as co-enzymes

dehydrogenase

inhibitor of complex II in oxidative phosphorylation

malonate

Associated with diabetic cataract (along with fructose)

sorbitol

Vitamin associated with carboxylation reactions

none of these:
B6
B2
B1
B12

cytochrome oxidase

oxidase

formed by breakdown of citrate by ATP Citrate Lyase

oxaloacetate

enzymes of glycolysis are deficient and affect skeletal muscle lead to...

fatigue

enzyme responsible for formation of a new covalent bond between condensation of two molecules

ligase

enzyme used in conversion of D-Glc-6-P to fructose-6-P

phosphohexose isomerase

conjugated glucuronides are formed by what process?

combination of uronic acid and xenobiotics

occurs when renal threshold of of Glucose is exceeded

glucosuria

2,4-dinitrophenol acts as _______ in the oxidative phosphorylation process

as an uncoupler molecule

Peroxisomes are rich in oxidases and _____

catalase

co-enzyme that reduces a substrate by transferring hydrogens from one substrate to O2

FAD

oxidizes a substrate using molecular oxygen as H acceptor

oxidases

Appears in urine with essential pentosuria

L-Xylulose

In PPP, enzyme that acts btwn. sedoheptulose-7-P and Glyceraldehyde-3-P to form Erythrose-4-P and fructose-6-P

transaldolase

L-aminoacid oxidase is used for what reaction?

oxidative deaminiation of amino acids

pathway for biosynthesis of sialic acids

Glc-6-P...Fru-6-P...GlcNAc-6-P...ManNAc-6-P...PEP...NeuAc...Sialic acid

DHAP is used for synthesis by esterification of...

Triacylglycerol (TAG)

conversion of TAG into fatty acids

lipolysis

citrate is allosteric modifier of the enzyme system that catalyzes what reaction?

fatty acid synthesis

LDH1 is inhibited by...

pyruvate

pyruvate is decarboxylated using CoASH to generate...

AcetylCoA

pellagra is caused by deficiency of tryptophan and which vitamin?

niacin

Hyperglycemia occurs in cells that have a high level of...

sorbitol

enzyme that converts ribulose-5-P to xylulose-5-P in PPP

3-epimerase

arginase hydrolyzes arginine to urea and _____ in the urea cycle

ornithine

in citric acid cycle, what reaction forms FADH2?

succinate to fumarate

Asn is metabolized to ____ in the citric acid cycle

oxaloacetate

galactosemia

inability to metabolize galactose

metabolism of what aa forms alpha ketoglutarate?

Glu

Tyr is metabolized to _____ of the citric acid cycle

fumarate

carboxylation of pyruvate forms _______

oxaloacetate

glutathione peroxidase catalyzes what reaction?

H2O2 + FADH2 = 2H2O + FAD

secreted in response to hyperglycemia and stimulates liver to store glucose as glycogen and facilitates uptake of glucose into extrahepatic tissues

insulin

first NADH formed in what step of citric acid cycle?

isocitrate to oxaloacetate

co-enzyme used by an enzyme system that reduces a substrate by transferring H from one substance to another

FAD and NAD+

tocophenols have vitamin ______ activity

E

catalase is an enzyme for what reaction?

2H2O2 = 2H2O + O2

flavoproteins are...

oxidases

enzyme that catalyzes conversion of fructose-6-P to Glc-6-P in the PPP

phosphohexose isomerase

enzyme used to convert pyruvate to oxaloacetate

pyruvate carboxylase

aa in glutathione peroxidase

selenocysteine

in urea cycle, aspartate + citrulline =

arginosuccinate

reaction in complex II

CoQ...CoQH2

precursor to PEP

oxaloacetate

where does uronic acid pathway occur?

liver

PFK-2 is used for what reaction?

Fructose-6-P to Fructose 2,6-bisphosphate

route for pyruvate converted to alcohol under anaerobic conditions

pyruvate...acetaldehyde...ethanol

cytochrome P450 is a...

monooxygenase

acts as anti-oxidant in the body

Vitamin E

deficient enzymes of glycolysis

hemolytic anemia

deficiency in what vitamin causes impaired fat and carb metabolism?

H

In citric acid cycle, Ala is metabolized to...

pyruvate