2016 biochem endterm Flashcards
what molecule participates in the transfer of fatty Acyl CoA to the mitochondrial matrix?
a. Carnitine
b. Ceramide
a. Carnitine
what molecule can induce the polymerization of ACC?
a) Acytel coA
b) Citrate
c) Oxaloacetate
d) Malonyl coA
b) Citrate
which of the following is fatty acid that can not be synthesized in the human body?
a) Oleic acid
b) Linoleic acid
c) Palmitate
d) Stearic acid
b) Linoleic acid
what is the function of HSL?
a) Converts diglycerides to monoglycerides
b) Converts triglycerides to diglycerides
c) Converts monoglycerides to fatty acids
a) Converts diglycerides to monoglycerides
what is the rate-limiting enzyme in cholesterol biosynthesis?
a) HMG CoA hydratase
b) HMG CoA reductase
c) HMG CoA synthetase
d) HMG CoA thiolase
b) HMG CoA reductase
what is the major precursor for cholesterol synthesis?
a) IPP
b) FPP
c) Pyrophosphomevalonate
d) Mevalonate
d) Mevalonate
what activates lipoprotein lipase in the circulation?
a) Ap B-48
b) Ap B-100
c) Ap C-11
d) Ap E
c) Ap C-11
In which form is the dietary lipid transported to the peripheral tissue?
a) VLDL
b) LDL
c) HDL
d) Chylomicron
d) Chylomicron
what is the product of esterification of sphingosine and fatty acid?
a) Ceramide
b) Cardiolipin
c) Phosphotidylinostiol
d) Phosphotidylcholine
a) Ceramide
what is the precursor of prostaglandins ?
a) Arachidonic acid
b) Oleic acid
c) Palmitic acid
d) Stearic acid
a) Arachidonic acid
what is used for both de novo and salvage pathway of purine synthesis?
a) Ribose-5-phosphate
b) Phosphoribosyl pyrophosphate (PRPP)
b) Phosphoribosyl pyrophosphate (PRPP)
what condition reduces the solubility of uric acid in fluid tissue?
a) High [Na]
b) High [H+]
c) High [Ca]
d) Low [glucose]
b) High [H+]
For a healthy cell, which of the following is true?
a. Phosphatidylserine is on the extracellular domain
b. Phosphatidylserine is on the cytoplasmic domain
c. Phosphatidylserine is not available in the cells
Phosphatidylserine is on the cytoplasmic domain
The increase of what component increases the fluidity of the membrane?
a) Cis-unsaturated fatty acids
b) Trans-unsaturated fatty acids
c) Acetyl coA
d) Lactate
b) Trans-unsaturated fatty acids
it says A in the LT
What is most likely to cause acidosis in prolonged fasting?
a) Gluconeogenesis from alanine
b) Increase in glycolysis
c) Increase in PPP
d) Ketone bodies production
d) Ketone bodies production
Which process is most important for the maintenance of blood glucose during fasting (4-12hrs)?
a) Gluconeogenesis by amino acids
b) Gluconeogenesis by glycerol
c) Glycogenlysis in the liver
d) Glycogenlysis in muscles
c) Glycogenlysis in the liver
What is produced by the spontaneous breakdown of ketone bodies?
a) Acetate
b) Acetone
c) Buytric acid
b) Acetone
Ketone bodies enable the transfer of which metabolites between cells and organs?
a) Diacylglycerol
b) Cholesterol
c) Acytel CoA
d) Lactate
c) Acytel CoA
What is the major source of trans fat in the western diet?
a) Vegetable oil
b) Fish oil
c) Hydrogenated oil
c) Hydrogenated oil
What effects do trans fats have on cholesterol level?
a) Decrease chylomicron
b) Decrease LDL
c) Increase HDL
d) Increase LDL
d) Increase LDL
What unsaturated fatty acid is synthesized de novo in the body?
a) C16:1 15
b) C16:2 15,17
c) C18:1, 9
c) C18:1, 9
why is linoleic acid (C18:2) an essential fatty acid?
a) Lack of ^ 12
b) Lack of ^ 9
c) High 18:4 desaturase
a) Lack of ^ 12
Which cells produce pepsin?
a) Chief cells
b) G cells
c) D cells
d) Parietal cells
a) Chief cells
Which hormone stimulates the release of pancreatic zygmones?
a) Cholecystokinin
b) Insulin
c) Gastrin
d) Vasopressin
a) Cholecystokinin
In which organ does the complete urea cycle take place?
a) Liver
b) Pancreas
c) Intestine
a) Liver
What enzyme catalyzes oxidative deamination?
a) Aspartate ammonia-lyase
b) Glutamate dehydrogenase
c) Glutaminase
d) Urease
b) Glutamate dehydrogenase
What is correct regarding metabolomics?
a) characterization of genomes
b) characterization of signalling molecules
c) understanding protein structure
d) understanding genome evolution
b) characterization of signalling molecules
What is the consequence if ADP or Pi was depleted in the mitochondria?
a) Proton pump activated
b) Transmembrane proton gradient decreases
c) Uncoupling of respiration of oxidative phosphorylation
d) Decrease oxygen consumption
d) Decrease oxygen consumption
What is the dragging force for pumping H+?
a) Oxidative decarboxlation
b) Hydrolysis of ATP
c) Electrochemical gradient
d) Reduction of O2 to H2O
d) Reduction of O2 to H2O
What causes the conformational change in the catalytic subunits?
a) Mechanical stress
b) ATP hydrolysis
c) Reduction of alpha subunit
d) Electrochemical gradient
a) Mechanical stress
The product of which enzyme acts as an allosteric activator of pyruvate kinase?
a) PFK-1
b) PFK-2
c) Fructose, 1-6, bisphosohate
a) PFK-1
Epinephrine in the heart activates which enzyme?
a) PFK-1
b) PFK-2
c) F26bp
b) PFK-2
What is the allosteric activator of PDH kinase?
a) ATP
b) cAMP
c) CoA
d) NAD+
a) ATP
I think D
This reaction is in the TCA and it produces GTP. What is the mechanism of producing GTP?
a) Oxidative phosphorylation
b) Oxidative decarboxylation
c) Substrate-level phosphorylation
c) Substrate-level phosphorylation
- picture showing pyruvate turning into lactate in muscle*
a) Krebs cycle
b) Urea cycle
c) Cori cycle
d) Alanine-glucose cycle
c) Cori cycle
Cori cycle= Pyruvate becomes lactate in muscle
Alanine-glucose cycle= Pyruvate becomes alanine in muscle
Which liver enzyme is activated when we have a high glucagon/insulin ratio?
a) Glucokinase
b) F1,6Bpase
c) Pyruvate kinase
d) PFK-1
b) F1,6Bpase
What is the main product in the oxidative stage of pentose phosphate pathway?
a) NADPH
b) ADP
c) ATP
d) NADH
a) NADPH
PPP is common in what kind of cell?
a. Cells with low rate of division
b. Cells with high rate of division
b. Cells with high rate of division
What is the immediate product of non-oxidative stage of PPP?
a) Production of Ribose-5-phosphate
b) Production of glucose-6-phosphate
c) Conversion of AMP to ATP
d) Conversion of NAD to NADH
a) Production of Ribose-5-phosphate
what enzyme catalyzes the following reaction?
O2-* + O2-*+ 2H+ H2O2 + O2
a) Myeloperoxidase
b) NDPH oxidase
c) Superoxide dismutase
d) Xanthineoxidase
c) Superoxide dismutase
what is the fate of GSSH?
Gets reduced by NADPH
I think they meant Glutathione disulfide (GSSG)
what is a characteristic of lipid membrane?
a) Amphipathic
b) Covalently attached
a) Amphipathic
What is the cause of cataract in people with galactosemia?
a) Accumulation of galactitol
b) Accumulation of UDP glucose
c) Depletion of galactose phosphate –1
d) Lack of ADP
a) Accumulation of galactitol
