Biochem Test 3 (11-16)

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

A) Acetyl
B) Acyl
C) Prenyl
D) Isoprenoid
E) Isopentenyl

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

A) Cis
B) Trans
C) Both cis and trans
D) Essential
E) Nonessential

3) The essential fatty acids are

A) Arachidonic acid
B) Linoleic acid
C) Linolenic acid
D) Both A and B are correct
E) Both B and C are correct

4) Fatty acids react with alcohols to form _____.

A) Amides
B) Ethers
C) Anhydrides
D) Epoxides
E) Esters

5) Prostaglandins are involved in _________.

A) Ovulation
B) Inflammation
C) Digestion
D) Both A and B are correct
E) All of the above are correct

6) The functions of fat include

A) Insulation
B) Energy storage
C) Water-repellent properties
D) Both A and B are correct
E) All of the above are correct

7) Waxes

A) Are complex mixtures of nonpolar lipids
B) Are esters formed from long-chain fatty acids and long-chain alcohols
C) Contain hydrocarbons, sterols, and alcohols
D) Both A and B are correct
E) Both A and C are correct

8) Phospholipids are

A) Structural components of membranes
B) Surface active agents
C) Rich energy sources
D) Both A and B are correct
E) All of the above are correct

9) Phosphatidylcholine is sometimes referred to as ______.

A) PIP2
B) Cephalin
C) Ceramide
D) Cardiolipin
E)None of the above are correct

10) The myelin sheath 

A) Surrounds nerve cell axons
B) Contains large amounts of cardiolipin
C) Facilitates nerve impulse transmission
D) Both A and B are correct
E) Both A and C are correct

11) All of the following are glycolipids except _________.

A) Sulfatides
B) Cerebrosides
C) Gangliosides
D) Both A and B are correct
E) None of the above are correct

12) The role of very low density lipoproteins is

A) Scavenging the cholesterol from cell membranes
B) Transporting of lipids from liver to tissues
C) Transporting of cholesterol esters to the liver
D) Both A and B are correct
E) All of the above are correct

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

A) Carotenoids are the only examples of the monoterpenes
B) The carotenes are hydrocarbon members of the carotenoids
C) Xanthophylls are oxygenated derivatives of the carotenes
D) Carotenoids are orange-colored pigments
E) None of the above are true

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

A) Fatty acids
B) Steroids
C) Isoprenoids
D) Waxes
E)  All of the above are lipids

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

A) Proteins
B) Phospholipids
C) Cholesterol
D) Water
E) None of the above are correct

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

A) Phosphatidyl choline
B) Phosphatidylethanolamine
C) Fatty acids
D) Cardiolipin
E) Unsaturated fatty acids

17) In the fluid mosaic model of membrane structure

A) Proteins form an inner layer between two layers of lipid
B) Proteins coat an inner layer of lipids
C) Proteins float in a lipid bilayer
D) Proteins are covalently bonded to the lipid bilayer
E) All of the above are true

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

A) It plays an important role in carbon dioxide transport in blood
B) It facilitates the chloride shift
C) Bicarbonate and chloride exchange occurs through the anion channel protein
D) The N-terminal methionine residue of the anion channel protein is prenylated
E) All of the above statements are true.

19) Energy requiring transport mechanisms include

A) Primary active transport
B) Diffusion
C) Facilitated diffusion
D) Both A and B are correct
E) Both A and C are correct

20) In simple diffusion a solute

A) Is propelled by random molecular motion
B) Moves up its concentration gradient
C) Moves across a membrane because of an input of free  energy.
D) Both A and B are correct
E) All of the above are correct

21) Which of the following statements is not true?

A) Membrane potential is an electrical gradient across a membrane.
B) A decrease in membrane potential is referred to as membrane depoalarization.
C) The term repolarization is defined as the reestablishment of the original membrane potential.
D) The diffusion of potassium ions out of a nerve cell make the inside of the membrane negative.
E) The sodium channel in muscle and nerve cells is a voltage-gated channel.

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

A) Chloride
B) Potassium
C) Proton
D) Sodium
E) Glucose permease

23) The function of glucose permease is an example of 

A) Primary active transport
B) Secondary active trasnport
C) Facilitated diffusion
D) Simple diffusion
E) None of the above are true

24) ω-6 Fatty acids

A) Have a double bond six carbon atoms from the carbonyl end of the chain
B) Have a double bond six carbon atoms from the methyl end of the chain
C) Have six double bonds in the molecule
D) Have three more double bonds than ω-3 fatty acids
E) Contain six trans double bonds in the molecule

25) Membrane receptors are transmembrane molecules or molecular complexes that 

A) Monitor and respond to changes in the cell’s environment.
B) Bind to hormones or neurotransmitters
C) Are involved in embryonic and fetal development
D) Initiate an intracellular response when they bind an appropriate molecule
E) All of the above are correct

26) Patients with familial hypercholesterolemia

A) Possess depressed levels of plasma cholesterol
B)  Have missing or defective LDL receptors
C)  Are homozygous or heterozygous for a nonfunctional LDL receptor gene
D) Have very high levels of serum cholesterol
E) B, C and D are correct

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

A) Oleic acid
B)  Arachidonic acid
C) Anandamine
D) Prostaglandin
E) ω-3 Fatty acids

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

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

A) An ether ring
B) One OH group
C) Two double bonds
D) One double bond
E) Is derived from arachidonic acid

30) Neutral fats belong to which of the following?

A) Phospholipids
B) Glycolipids
C) Prostaglandins
D)  Triacylglycerols
E) Free fatty acids

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



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

Choose the lipid class that acts as  surfactants.



Triacylglycerols
Fatty acids
Waxes
Phospholipids
Both A and B are correct

Membrane proteins are linked to anchor molecules through a ___________ link



Ether
Ester
Amide
Amino
Plasma

Glycolipids differ from sphingolipids in that they contain no _________.



Carbohydrate
Phosphate
Fatty acid
Choline
Both B and C are correct

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



C13H27COOH
C14H29COOH
C15H31COOH
C17H35COOH
C19H39COOH

How many isoprene units does a diterpene contain?



1
2
3
4
5

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

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

_________ 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

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



Water
Chloride
Potassium
Protein
Sodium

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

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

43) Phospholipase B hydrolyzes ______ ester bonds in phospholipids


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

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


Membrane remodeling
Signal transduction
Energy storage
Digestion
Toxic Phospholipases

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

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


Phospholipids
Cholesterol
Triacylglycerols
Glycolipids
Water

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

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

3)  The b-oxidation of fatty acids requires_________.

4. ________, a product of the oxidation of odd-chain fatty acids, is converted to  succinyl-CoA.

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

6) The carbon atoms of cholesterol are derived from _____

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

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

9) The acetyl-CoA derived from glyoxysomal b-oxidation is converted to carbohydrate via the

10. Refsum’s disease results from a buildup of _________ in nerve tissue.

11) Which of the following is not one of the ketone bodies?

12. Most eicosanoids are derived from either _________.

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

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

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

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

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

18)  Desaturation of fatty acids involves all of the following except

19)   Which of the following types of fatty acid oxidation produces a dicarboxylic
acid?

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

21) The conversion of acyl-CoA to acylcarnitine is inhibited by

22) In conjugation reactions

23) Depending on an animal’s metabolic needs, fatty acids may be converted to triacylglycerols, energy or

24) Membrane remodeling

25) The conversion of phosphatidylethanolamine to phosphatidylcholine requires

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

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

28) The conversion of squalene to cholesterol requires

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

30) Most bile acids are conjugated with

31) Which of the following tissues cannot use fatty acids as a fuel?

32) Lipolysis is used to:

Oxidation of the carbon farthest from the carbonyl group of a fatty acid is called

34) In the process of thiolytic cleavage  the following occurs:

35) How many FADH2 molecules would be produced in the oxidation of palmitic acid?

36) The rate limiting step in fatty acid synthesis is

37)  Which of the following lipids have signaling functions?

38) What form of oxidation is characteristic of branched chain fatty acids

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

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

41)   The absorption of triglycerides and other lipid nutrients and their distribution to body tissues is referred to as the

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

43)  Which of the following is not a function of lipids:

The triacylglycerol cycle is :

45) The principal means of producing glycerol in the body

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

1) The glutamate family of amino acids includes all of the following except _____.
a. Glutamate
b. Arginine
c. Lysine
d. Proline
e. None of the above

2)  Which of the following is an example of an excitatory neurotransmitter?
a. Seratonin
b. Glycine
c. Glutamine
d. Glutamate
e. None of the above are correct

3) All of the following are referred to collectively as the branched chain amino acids except _________
a. Valine
b. Glycine
c. Leucine
d. Isoleucine
e. None of the above are correct

4) Which of the following is an example of an inhibitory neurotransmitter?

Glycine is used as a precursor molecule in the synthesis of all of the following except _______.

6) In plants fixed nitrogen is assimilated into __________.

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

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

9) Tryptophan is a precursor in the synthesis of _________.

10) Chorismate is a precursor in the synthesis of all of the following except _______.

11) Molecules involved in histidine synthesis include ________.

folic acid

13) SAM is a methyl donor in the synthesis of ______.

14) Amethopterin is a structural analogue of _________.

GSH is? Important why?

16) All of the following are purine bases except _____.

17) Deficiency of _____________ causes Lesch-Nyhan syndrome

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

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

23) Which of the following is an a-keto acid/a-amino acid pair used in transamination?

24) In plants the pathway by which most ammonium ion is incorporated into organic molecules requires

25) Asparagine is formed from aspartic acid and ______.

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

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

28) The methylated product of _______ is creatine.

29) The fixation of nitrogen requires

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

31) The primary energy source for enterocytes is:

_______ ATP molecules are required to convert one mole of nitrogen to two ammonia molecules.

33) The first step in nitrogen fixation is  ___

34) The major form of regulation of nitrogen fixation is _______.

35) The first amino acid containing newly fixed nitrogen is _______.

36) Which of the following is not a gasotransmitter?

37)  Which of the following compounds is not present in the normal process of nitrogen fixation

38) Hydrogen sulfide is produced from

39) The six families of amino acids are glutamate, aromatic, serine, aspartate, pyruvate and _______.

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

41) In ocean water phytoplankton growth is limited  by temperature and low levels of nutrients containing

42) Hypoxic water is characterized by

43) The ultimate products of mineralization of organic nitrogen is

44)  The most common intracellular reducing agent is

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

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

1) In addition to urea humans also excrete waste nitrogen as

2) Stress proteins

3) The ammonia that is incorporated into urea molecules is produced in reactions catalyzed by all of the following enzymes except

4) N-Acetylglutamate is

5) Amino acids whose degradation yields acetyl-CoA include all of the following except

6) Homogentisate is an intermediate in the degradation of

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

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

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

10) Glutamate-g-semialdehyde is an intermediate in the degradation of

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

2) Alkaptonuria is caused by a deficiency of :

13) Albinism is caused by the absence of:

14) The major route for protein degradation is

15) Which of the following reactions require SAM?

16) The production of antibodies

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.

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

20) The end product of uracil degradation is

21) The end product of thymine degradation is

22) Dihydropyrimidine dehydrogenase catalyzes the conversion of

23) The glucogenic amino acids include all of the following except ______.

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

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 _______.

Propionyl-CoA and L-methylmalonyl-CoA are intermediates in the conversion of ______ and _____ to succinyl-CoA

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

30) Methylmalonic acidemia results from a deficiency of

31) The main nitrogen storage molecule in animals is

32) Decomposers convert organic nitrogen to

33) In general, catabolism of amino acids begins with

34) In muscle excess amino groups are transferred to _________ to produce glutamate

35) Ammonia is transferred to the liver as

36) Urea is synthesized in which organ?

37) In patients with alkaptonuria the urine is colored

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

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

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

41) Autophagy is

42) Phagocytosis is

43) Proteosomal digestion of what type of protein does not require ubiquination

44) Autophagy is triggered by

45) The ultimate products of autophagy include

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