Biochem Test 3 (11-16)

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1) Fatty acid groups are referred to as ________ groups.

C)
2) The double bonds in naturally occurring fatty acids are usually _______ isomers.

A)
3) The essential fatty acids are

E)
4) Fatty acids react with alcohols to form _____.

D)
5) Prostaglandins are involved in _________.

E)
6) The functions of fat include

E)
7) Waxes

E)
8) Phospholipids are

D)
9) Phosphatidylcholine is sometimes referred to as ______.

E)
10) The myelin sheath

E)
11) All of the following are glycolipids except _________.

E)
12) The role of very low density lipoproteins is

B)
13) Which of the following statements concerning carotenoids is not true?

A)
14) Which of the following molecules is not a lipid?

E)
15) The basic structure of biological membranes is a consequence of the physical properties of _______.

B)
16) A membrane’s fluidity is largely determined by the percentage of

D)
17) In the fluid mosaic model of membrane structure

C)
18) Which of the following statements concerning the anion channel protein is not true?

D)
19) Energy requiring transport mechanisms include

A)
20) In simple diffusion a solute

A)
21) Which of the following statements is not true?

D)
22) In muscle cells, local depolarization caused by acetylcholine binding leads to the opening of the voltage gated _____channels.

A)
23) The function of glucose permease is an example of

B)
24) ω-6 Fatty acids

C)
25) Membrane receptors are transmembrane molecules or molecular complexes that

E)
26) Patients with familial hypercholesterolemia

A)
27) Indicate which of the following compounds is a endocannabinoid.

A)
28) Low fat diets deficient in essential fatty acids are characterized by which of the following?

A) Poor wound healing
B) Alopecia
C) Dental caries
D Ketone bodies
E) Both A and B are correct

E
29) Which of the following structural features is not characteristic of TXA2 ?

E)
30) Neutral fats belong to which of the following?

B)
In addition to the prostaglandins and leukotrienes the autocrine regulators include:

Arachidonic acid
Linoleic acid
Thromboxanes
Steroids
All of the above are correct

C
Choose the lipid class that acts as surfactants.

Triacylglycerols
Fatty acids
Waxes
Phospholipids
Both A and B are correct

D
Membrane proteins are linked to anchor molecules through a ___________ link

Ether
Ester
Amide
Amino
Plasma

C
Glycolipids differ from sphingolipids in that they contain no _________.

Carbohydrate
Phosphate
Fatty acid
Choline
Both B and C are correct

B
Which of the following is not likely to be a naturally occurring fatty acid

C13H27COOH
C14H29COOH
C15H31COOH
C17H35COOH
C19H39COOH

B
How many isoprene units does a diterpene contain?

1
2
3
4
5

D
The function of dolichols is to

Transport sugars in glycoprotein synthesis
Bind carbohydrate on the cell surface of bacteria
Bind to oxygenated carotenes
Serve as precursors of carotenoids
They are degradation products of steroids

A
Plasma lipoproteins transport _______ through the blood from one organ to another.

Triacylglycerols
Phospholipids
Cholesteryl esters
Both A and C are correct
All of the above are correct

E
_________ are the principal transporters of cholesteryl esters to tissues.

Chylomicrons
Very low density lipoprotein
Intermediate density lipoprotein
Low density lipoprotein
All of the above are true

D
Individuals with cystic fibrosis have a defective _______ ion channel in their epithelial membrane

Water
Chloride
Potassium
Protein
Sodium

B
A consequence of replacing dietary fat content with sugars is

No effect on body weight
An increase in body weight
A small loss of body weight
A large decrease in body weight
An initial loss of weight followed by a large increase in body weight

B
Which of the following is not a consequence of a low fat diet?

Low levels of fat soluble vitamins
Low levels of essential fatty acids
Brittle hair
Poor would healing
Low blood pressure

E
43) Phospholipase B hydrolyzes ______ ester bonds in phospholipids

C-1
C-2
C-3
Both C-1 and C-2
All of the above

D
44) Which of the following is not a function of phospholipases?

Membrane remodeling
Signal transduction
Energy storage
Digestion
Toxic Phospholipases

C
45) Membranes are rigid when they contain

Large amounts of cholesterol
Large amounts of unsaturated fatty acids
Large amounts of saturated fatty acids
Large amounts of water
A and B

C
46) Flippase transfers _________ from the outer to inner membrane leaflet

Phospholipids
Cholesterol
Triacylglycerols
Glycolipids
Water

A
1. How many acetyl-CoA’s are required to synthesize one molecule of isopentenyl pyrophosphate

3
2. ______ is used to transport fatty acids into the mitochondria.

B-Oxidation and carnitine carrier system
3) The b-oxidation of fatty acids requires_________.

Acyl-CoA, FAD, NAD+, and CoASH
4. ________, a product of the oxidation of odd-chain fatty acids, is converted to succinyl-CoA.

Propionyl-CoA
5) __________ derive a substantial amount of energy from the oxidation of odd-chain fatty acids.

Ruminant animals (cattle and sheep)
6) The carbon atoms of cholesterol are derived from _____

Acetyl CoA
7) The following reaction requires the presence of beta-hydroxyacyl-CoA dehydrogenase
NAD+.

NAD+
8) In animals the function of peroxisomal b-oxidation appears to be

OX of odd chain fatty acids
9) The acetyl-CoA derived from glyoxysomal b-oxidation is converted to carbohydrate via the

citric acid cycle, CO2, NADH, H2O, FADH2, glyoxylate cycle and gluconeogenesis
10. Refsum’s disease results from a buildup of _________ in nerve tissue.

phytanic acid
11) Which of the following is not one of the ketone bodies?
- B-methyl- glutate
- Ketone bodies INCLUDE: Excess Acetyl CoA, Acetone, Acetoacetate and Beta-hydroxybutyrate.
12. Most eicosanoids are derived from either _________.

arachidonic acid
13) Glycerol from the hydrolysis of triacylglycerols is transported by the blood to the

Liver
14) The intermediates in fatty acid synthesis are linked through a ______ linkage to ACP.

thioester
15) Saturated fatty acids containing up to 16 carbon atoms are assembled in

cytoplasm
16) Fatty acid synthesis begins with the carboxylation of acetyl CoA to form

malonyl COA.
17) All of the following are enzymatic activities found in fatty acid synthase except

liboxygenase
18) Desaturation of fatty acids involves all of the following except
- Desaturation is important in the regulation of membrane fluidity(done in
- ER) and the synthesis of the precursors for a variety of fatty acid
- derivatives such as the eicosanoids.
- The system efficiently introduces double bonds (desaturation) into
- long-chain fatty acids
- Mediated by an electron transport system
- (The answer will be none of the above)
- INVOLVES: Cytochrome b5 reductase, cytochrome b5 and desaturase, NADH, O2
19) Which of the following types of fatty acid oxidation produces a dicarboxylic
acid?

alpha oxidation
20) The conversion of acetyl-CoA to malonyl-CoA is inhibited by

glucagon, epinephrine, paltimitoyl coa
21) The conversion of acyl-CoA to acylcarnitine is inhibited by

malonyl COA.
22) In conjugation reactions
- This reaction improve the water solubility of a molecule by converting it to a derivatives (Amid and Esters) that contains a water-soluble group.
- Most bile acids are conjugated with glycine
23) Depending on an animal’s metabolic needs, fatty acids may be converted to triacylglycerols, energy or

membrane synthesis.
24) Membrane remodeling

Cells use phospholipases to alter the flexibility of membranes by adjusting the ratio of saturated and unsaturated fatty acids or to replace a damaged fatty acid. Fatty acid removal from a phospholipid is followed by a reacylation reaction catalyzed by an acyltransferase.
25) The conversion of phosphatidylethanolamine to phosphatidylcholine requires

SAM

enzyme phosphotidylethanolamine-N-methyltransferase.
26) The sulfatides are synthesized when galactocerebriose reacts with
3-phosphoadenosine-5’-phosphosulfate.

Galactocerebroside
27) __________ is the rate-limiting enzyme in cholesterol synthesis.

HMG-CoA reductase (HMGR)
28) The conversion of squalene to cholesterol requires

sterol carrier protein because the conversion of squalene to lanosterol occurs while the intermediates are bound to this protein.

The answer is NADPH
29) Cholesterol is a precursor of synthesis of important metabolites used to

form bile salt, bile salts, steroid hormones nascent lipoproteins.
30) Most bile acids are conjugated with

glycine or taurine.
31) Which of the following tissues cannot use fatty acids as a fuel?

Brain cells and RBC cannot use fatty acids as fuels.
32) Lipolysis is used to:
- Lipolysis is the enzyme-catalyzed hydrolysis of triacylglycerol molecules.
- When energy reserves are low, the body’s fat stores are mobilized in this process. It usually occurs during fasting or vigorous exercise and stress
form fatty acids and glycerol from degradation of triacylglycerols when energy reserves are low.
Oxidation of the carbon farthest from the carbonyl group of a fatty acid is called

omega oxidation
34) In the process of thiolytic cleavage the following occurs:
- an acetyl-CoA molecule is released
- The other product, acyl-CoA, contains two fewer C atoms
35) How many FADH2 molecules would be produced in the oxidation of palmitic acid?

7
36) The rate limiting step in fatty acid synthesis is

acetyl COA Carboxylation
37) Which of the following lipids have signaling functions?

Steroid hormones and prostaglandins.
38) What form of oxidation is characteristic of branched chain fatty acids

alpha oxidation
39) The metabolism of fatty acids is regulated in the short term by allosteric modulators, covalent modification and

hormones
40) The most important mechanism for degrading and eliminating cholesterol is the synthesis of

bile acids in the ER of liver cells.
41) The absorption of triglycerides and other lipid nutrients and their distribution to body tissues is referred to as the

exogenous pathway
42) The pathway in which lipoproteins are transported from the liver to cells is referred to

endogenous pathway
43) Which of the following is not a function of lipids:
Function of lipids : vital energy reserves, primary structural components of biological membranes, act as hormones, antioxidants, pigments, or vital growth factors and vitamins
- Highly efficient and compact energy storage molecules
- Essential components of biological membranes (phospholipids, cholesterol, sphingolipids)
- Diverse membrane-associated molecules that have signaling or protective functions
The triacylglycerol cycle is :

A mechanism that regulates the level of fatty acid that are available to the body for the energy generation and synthesis of molecules such as phospholipids.
45) The principal means of producing glycerol in the body

glyceroneogensis
46) The recycling rate of triacylglycerols to fatty acids is inhibited by

insulin
1) The glutamate family of amino acids includes all of the following except _____.

C.
2) Which of the following is an example of an excitatory neurotransmitter?

D.
3) All of the following are referred to collectively as the branched chain amino acids except _________

E.
4) Which of the following is an example of an inhibitory neurotransmitter?
- GABA is most prevalent inhibitory
- Glycine
Glycine is used as a precursor molecule in the synthesis of all of the following except _______.

Glycine is used in the purine, porphyrin, and glutathione synthetic pathways
6) In plants fixed nitrogen is assimilated into __________.

the amide group of glutamate
7) a-Ketoisovalerate is an intermediate formed during the synthesis of _________.

valine and leucine
8) The group of molecules called the catecholamines include all of the following except

The most abundant ones ARE: Norepinephrine, epinephrine, dopamine.
9) Tryptophan is a precursor in the synthesis of _________.
- Serotonin
- Niacin
- auxin
- β-carboline norharman
10) Chorismate is a precursor in the synthesis of all of the following except _______.

tryptophan, tyrosine, phenylalanine. also: prephenate
11) Molecules involved in histidine synthesis include ________.

phosphoribosylpyrophosphate (PRPP), ATP, and glutamine
folic acid

A vitamin of the B complex, found esp. in leafy green vegetables, liver, and kidney. A deficiency causes megaloblastic anemia
13) SAM is a methyl donor in the synthesis of ______.

115 transmethylation reactions some which which occur in the synthesis of phospholipids,several neurotransmitters, and glutathione.
14) Amethopterin is a structural analogue of _________.

Folate
GSH is? Important why?

It is an antioxidant, preventing damage to important cellular components caused by reactive oxygen species such as free radicals and peroxides. May reduce cancer development
16) All of the following are purine bases except _____.

purine bases include: adenine, guanine, xanthine, and hypoxanthine.
17) Deficiency of _____________ causes Lesch-Nyhan syndrome

Hypozanthine-guanine phosphoribosyltransferase (HGPRT)
18) All of the following are directly involved in the synthesis of deoxyribonucleic acid....
19) Inorganic nitrogen is initially assimilated into which of the following amino acids

glutamine, glutamate, asparagine, and aspartate
20) The amino acids serine and _______ are preferentially used to synthesize glucose for export from the liver
21) Nitrogen fixation requires iron and ________ as cofactors.
22) One-carbon carriers in metabolism include

SAM and tetrahydrofolate THF (folic acid)
23) Which of the following is an a-keto acid/a-amino acid pair used in transamination?

a-ketoglutarate/glutamate, oxaloacetate/ aspartate, pyruvate/ alanine
24) In plants the pathway by which most ammonium ion is incorporated into organic molecules requires
25) Asparagine is formed from aspartic acid and ______.

glutamine.
26) The benzene ring of the aromatic amino acids is formed by the

shikimate pathway
27) The oxidation state of the methenyl group (-CH=) is comparable to that of ____.

formyl (-CHO)
28) The methylated product of _______ is creatine.

L-arginine, glycine, and L-methionine
29) The fixation of nitrogen requires

Anaerobic Conditions
30) Most aminotransferaes utilize ________as the recipient a-keto acid.

a-ketoglutarate
31) The primary energy source for enterocytes is:

short-chain fatty acids
_______ ATP molecules are required to convert one mole of nitrogen to two ammonia molecules.

16
33) The first step in nitrogen fixation is ___

reduction of atmospheric nitrogen by nitrogen-fixing bacteria to yield ammonia NH3 or NH4
34) The major form of regulation of nitrogen fixation is _______.

transcriptional control of approximately 20 nitrogen fixation genes
35) The first amino acid containing newly fixed nitrogen is _______.

glutamate
36) Which of the following is not a gasotransmitter?

examples of gasotransmitters are: nitric oxide, hydrogen sulfide, carbon monoxide, and nitrous oxide
37) Which of the following compounds is not present in the normal process of nitrogen fixation
38) Hydrogen sulfide is produced from

cysteine by several enzymes [pyridoxal phosphate requiring enzymes cystathione beta-synthetase (CBS) and CSE]
39) The six families of amino acids are glutamate, aromatic, serine, aspartate, pyruvate and _______.

histidine
40) Which of the following neurotransmitters are derived from amino acids?

GABA, catecholamines, serotonin, and histamine
41) In ocean water phytoplankton growth is limited by temperature and low levels of nutrients containing

nitrogen (and phosphorous)
42) Hypoxic water is characterized by

low oxygen conditions
43) The ultimate products of mineralization of organic nitrogen is

NH3, NO3-, NO2- (nitrite), and eventually N2
44) The most common intracellular reducing agent is

glutathione
45) In nitrogen fixation by microorganisms what gas other than ammonia is produced?

hydrogen gas
46) Which of the following is not a function of glutathione

Glutathione is an antioxidant - protects the body against oxidative stress, radiation, uv light, etc.
1) In addition to urea humans also excrete waste nitrogen as

Uric Acid
2) Stress proteins

are referred to as heat shock proteins
3) The ammonia that is incorporated into urea molecules is produced in reactions catalyzed by all of the following enzymes except

L-amino acid oxidases, Serine and threonine dehydrases, Bacterial ureases (intestinal bacteria), and Adenosine deaminase produce NH4
4) N-Acetylglutamate is

produced from glutamate and acetyl-CoA, and stimulates the activity of carbonyl synthetase 1
5) Amino acids whose degradation yields acetyl-CoA include all of the following except

glutamate
6) Homogentisate is an intermediate in the degradation of

tyrosine
7) a-Ketoadipate is an intermediate in the degradation of

lysine.
8) In addition to phenylalanine-4-monooxygenase the conversion of phenylalanine to tyrosine requires

O2, BH4, NADPH
9) Amino acids whose degradation yields a-ketoglutarate include all of the following except _________.

Arginine, Histidine, Glutamate, Glutamine, and Proline degrade to alpha-ketoglutarate.
10) Glutamate-g-semialdehyde is an intermediate in the degradation of

proline
11) Amino acids whose degradation yields succinyl-CoA includes all of the following except ________.

Methionine, Isoleucine, Threonine, and Valine are converted to succinyl-coa
2) Alkaptonuria is caused by a deficiency of :

homogentisate oxidase, an enzyme required for the catabolism of aromatic ring of phenylalanine and tyrosine.
13) Albinism is caused by the absence of:

pigment (lack of melanin)
14) The major route for protein degradation is

Ubiquitin Proteosomal System (UPS)
15) Which of the following reactions require SAM?

Conversion of norepinephrine to epinephrine
16) The production of antibodies

occurs in the B cells and is referred to as the humoral immunity response
17) Which of the following is not a characteristic N-terminal amio acid residue of long-lived proteins
18) Covalently bound chains with _____ or more ubiquitin monomers are required to transfer a protein to the proteosome.

4
19) Which of the following amino acids reacts with HOCl to form a nontoxic product during respiratory bursts?

Taurine
20) The end product of uracil degradation is

b-alanine
21) The end product of thymine degradation is

b-aminoisobutyrate.
22) Dihydropyrimidine dehydrogenase catalyzes the conversion of

uracil to dihydrouracil and thymine to dihydrothymine
23) The glucogenic amino acids include all of the following except ______.

All amino acids except Lysine, and Leucine
24) Components of the transulfuration pathway include all of the following except _____.
25) In adenosine deaminase deficiency large concentrations of dATP result in the inhibition of

ribonucleotide reductase.
26) Which of the following tissues can only replenish citric acid cycle intermediates by the purine nucleotide cycle?
27) All of the following are directly involved in protein turnover except _______.
- lysosomal proteases--> endocytosed proteins
- cytoplasmic complexes (proteasomes)
Propionyl-CoA and L-methylmalonyl-CoA are intermediates in the conversion of ______ and _____ to succinyl-CoA

isoleucine and valine
29) The end products of the transulfuration pathway are sulfate and

pyruvate
30) Methylmalonic acidemia results from a deficiency of

Vitamin B12
31) The main nitrogen storage molecule in animals is

Ammonia
32) Decomposers convert organic nitrogen to

ammonia
33) In general, catabolism of amino acids begins with

removal of the amino group
34) In muscle excess amino groups are transferred to _________ to produce glutamate

alpha-ketoglutarate
35) Ammonia is transferred to the liver as

glutamine
36) Urea is synthesized in which organ?

Liver (specifically hepatocytes)
37) In patients with alkaptonuria the urine is colored

black
38) High phenylalanine blood levels from phenylketonuria results in damage to which organ?

The brain
39) Which of the following conditions result in a buildup of a-ketoacids derived from branced chain amino acids?

Diabetic Ketoacidosis
40) A buildup of uric acid is characteristic of which of the following diseases?

Branched chain ketoaciduria
41) Autophagy is

the basic catabolic mechanism that involves cell degradation of unnecessary or dysfunctional cellular components through the lysosomal machinery
42) Phagocytosis is
- the ingestion of bacteria or other material by phagocytes and ameboid protozoans
- ingestion by local folding of cell membrane
43) Proteosomal digestion of what type of protein does not require ubiquination
44) Autophagy is triggered by

Starvation (lack of any type of essential nutrient)
45) The ultimate products of autophagy include

Amino Acids
46) The major catabolic mechanism used by eukaryotic cells to maintain optimal function and respond to changing environmental conditions is

ubiquitin-proteasome pathway

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Card Set

Biochem Test 3 (11-16)

Description

Rutgers intro to biochem with Murphy test 3 chapters 11-16

Updated

2013-04-10T03:01:26Z

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