Biochemistry

Most proteins absorb light at a wavelength of 280 nm. Which of the following amino acids is ...

Most proteins absorb light at a wavelength of 280 nm. Which of the following amino acids is ...

Most proteins absorb light at a wavelength of 280 nm. Which of the following amino acids is primarily responsible for this absorption?
 a. glycine
 b. histidine
 c. proline
 d. tryptophan
 e. cysteine

alshernandez   46   2 Replies

alshernandez

Which of the following amino acids lacks an asymmetric carbon atom?

Which of the following amino acids lacks an asymmetric carbon atom?

Which of the following amino acids lacks an asymmetric carbon atom?
 a. serine
 b. glycine
 c. histidine
 d. glutamine
 e. leucine

stalmoney   40   1 Reply

Nickluna@msn.co

Isomers that differ at only one of the asymmetric centers are called:

Isomers that differ at only one of the asymmetric centers are called:

Isomers that differ at only one of the asymmetric centers are called:
 a. diastereomers
 b. dextrorotatory
 c. levorotatory
 d. prochiral
 e. isoelectric

adamsnaya   43   1 Reply

Lettyyys

Acid hydrolysis of proteins in order to determine the amino acid composition leaves most of the ...

Acid hydrolysis of proteins in order to determine the amino acid composition leaves most of the ...

Acid hydrolysis of proteins in order to determine the amino acid composition leaves most of the amino acid residues intact but:
 a. destroys proline
 b. oxidizes leucine to isoleucine
 c. converts asparagine to aspartic acid
 d.

Griffinw42   50   1 Reply

jeooncdaoc

Enzymes are catalysts that: (Multiple Choice)

Enzymes are catalysts that: (Multiple Choice)

Enzymes are catalysts that:
 a. accelerate the rates of biological reactions
 b. inhibit the formation of unwanted metabolites
 c. change the equilibrium constants of reactions
 d. are generally non-specific in reactions they cat

sophie0209   42   1 Reply

mrperretti

One of the steps often employed during polypeptide purification is the cleavage of disulfide bridges ...

One of the steps often employed during polypeptide purification is the cleavage of disulfide bridges ...

One of the steps often employed during polypeptide purification is the cleavage of disulfide bridges between polypeptide chains by reduction with compounds such as 2-mercaptoethanol. However, the bridges tend to reform. To prevent this the peptides a

alexiswells   52   1 Reply

elizabethxo1

The partial double bond character of the peptide bond:

The partial double bond character of the peptide bond:

The partial double bond character of the peptide bond:
 a. restricts rotation around the C-N bond
 b. allows free rotation around the C-N bon
 c. restricts rotation around the Ca-C bond
 d. restricts rotation around the N-Ca bond

Jnortontruvisio   87   2 Replies

Jnortontruvisio

The peptide linkage between amino acids has partial double bond character. Because of this

The peptide linkage between amino acids has partial double bond character. Because of this

The peptide linkage between amino acids has partial double bond character. Because of this
 a. There is free rotation around the peptide bond.
 b. The carbonyl and amino groups always reside on the same side of the bond.
 c. The cis c

stalmoney   66   1 Reply

gecko.girl

In the solid phase synthesis of peptides, which of the following compounds is often used for ...

In the solid phase synthesis of peptides, which of the following compounds is often used for ...

In the solid phase synthesis of peptides, which of the following compounds is often used for blocking amino groups during synthesis?
 a. tertiary butyloxycarbonyl chloride
 b. dicyclohexyl carbodiimide
 c. dicyclohexyl urea
 d. m

sophie0209   29   1 Reply

P.liania

A heteromultimeric protein: (Multiple Choice)

A heteromultimeric protein: (Multiple Choice)

A heteromultimeric protein:
 a. contains only one polypeptide chain
 b. contains multiple copies of the same polypeptide chain
 c. contains modified amino acids in the polypeptide chains
 d. contains multiple polypeptide chains a

Pooh bear   46   1 Reply

Nrcp1978

The arrangement of the two alpha and two beta polypeptide chains in hemoglobin is an example of the ...

The arrangement of the two alpha and two beta polypeptide chains in hemoglobin is an example of the ...

The arrangement of the two alpha and two beta polypeptide chains in hemoglobin is an example of the _______ structure of a protein.
 a. primary
 b. secondary
 c. tertiary
 d. quarternary
 e. septernary

kristina92293   53   1 Reply

ally

Which of the following statements about hydrophobic bonds is false?

Which of the following statements about hydrophobic bonds is false?

Which of the following statements about hydrophobic bonds is false?
 a. The forming of hydrophobic bonds maximizes the interaction of nonpolar residues with water.
 b. They form because nonpolar side chains of amino acids and other nonpola

Revolver38   35   1 Reply

PurpleMonkey

Which of the following statements about electrostatic interactions is false?

Which of the following statements about electrostatic interactions is false?

Which of the following statements about electrostatic interactions is false?
 a. They arise either as electrostatic attractions between opposite charges or repulsions between like charges.
 b. Electrostatic interactions between charged gro

Linalovespickle   43   2 Replies

Linalovespickle

Which of the following statements about Van der Waals interactions is false?

Which of the following statements about Van der Waals interactions is false?

Which of the following statements about Van der Waals interactions is false?
 a. They can arise due to instantaneous dipole-induced dipole interactions.
 b. They consist of both attractive forces and repulsive forces.
 c. Individual v

Jovaini   35   1 Reply

shonsber

A Ramachandran diagram: (Multiple Choice)

A Ramachandran diagram: (Multiple Choice)

A Ramachandran diagram:
 a. indicates where the Van der Waals interactions are in a protein
 b. indicates where electrostatic interactions are stabilizing a protein
 c. indicates the sterically reasonable values of the angles f and y

mahi   33   1 Reply

jogden1011

One turn of an a-helix represents ___ amino acid residues.

One turn of an a-helix represents ___ amino acid residues.

One turn of an a-helix represents ___ amino acid residues.
 a. 2.6
 b. 3
 c. 3.6
 d. 4
 e. none of the above

avaaaaa   49   1 Reply

hennihanadi

Which of the following statements is (are) true about an a-helix?

Which of the following statements is (are) true about an a-helix?

Which of the following statements is (are) true about an a-helix?
 a. The side chains extend outward from the core structure of the helix.
 b. All of the H-bonds lie parallel to the helix axis.
 c. All of the carbonyl groups point in

tarapratt95   37   1 Reply

hellokristi4

Which of the following amino acids has a tendency to destabilize a-helices?

Which of the following amino acids has a tendency to destabilize a-helices?

Which of the following amino acids has a tendency to destabilize a-helices?
 a. glycine
 b. proline
 c. tyrosine
 d. valine
 e. histidine

sarah_verduzco1   53   1 Reply

steffers12

Which of the following statements about beta-pleated sheets (b-sheets) is false?

Which of the following statements about beta-pleated sheets (b-sheets) is false?

Which of the following statements about beta-pleated sheets (b-sheets) is false?
 a. Adjacent chains of amino acids that form b-sheets always run in the same direction (N --> C or C --> N).
 b. They arise due to cooperative formation of hy

avaaaaa   75   2 Replies

avaaaaa

Which of the following statements about fibrous proteins is false?

Which of the following statements about fibrous proteins is false?

Which of the following statements about fibrous proteins is false?
 a. They contain polypeptide chains organized approximately parallel along a single axis.
 b. The organization of the polypeptide chains produces long fibers or large sheet

Pooh bear   44   1 Reply

kpennies

Collagen fibers have a high content of which amino acids?

Collagen fibers have a high content of which amino acids?

Collagen fibers have a high content of which amino acids?
 a. histidine, tyrosine, and proline
 b. proline, hydroxyproline, and tyrosine
 c. alanine, phenalanine, and isoleucine
 d. cysteine, methionine, and phenalanine
 e.

stalmoney   41   1 Reply

Jenkinas

Which of the following statements about globular proteins is true?

Which of the following statements about globular proteins is true?

Which of the following statements about globular proteins is true?
 a. They are not as abundant in nature as fibrous proteins.
 b. They do not contain substantial amounts of b-sheets.
 c. It is common in globular protein structures fo

hessar3   71   1 Reply

MSROGERS

Which of the following motions occur(s) in proteins?

Which of the following motions occur(s) in proteins?

Which of the following motions occur(s) in proteins?
 a. atomic vibrations
 b. collective motions
 c. conformational changes
 d. a, b, and c
 e. b and c

Angela26kristin   37   1 Reply

bbebe

The term used to refer to how individual polypeptide chains of a protein having two or more chains ...

The term used to refer to how individual polypeptide chains of a protein having two or more chains ...

The term used to refer to how individual polypeptide chains of a protein having two or more chains are arranged in relation to each other is:
 a. primary structure
 b. secondary structure
 c. tertiary structure
 d. quaternary str

crownlessking   87   1 Reply

Andecv

Which of the following sets of amino acid residues would you most likely find on the exterior ...

Which of the following sets of amino acid residues would you most likely find on the exterior ...

Which of the following sets of amino acid residues would you most likely find on the exterior surface of a globular protein at physiological pH?
 a. Phe, Asn, Glu, Trp
 b. Ala, Phe, Asp, Glu
 c. Thr, Met, Glu, Arg
 d. Glu, Asp, A

bronzeclock   46   1 Reply

ashleyjohnson81

The basic structural unit of collagen, tropocollagen, has the following structure:

The basic structural unit of collagen, tropocollagen, has the following structure:

The basic structural unit of collagen, tropocollagen, has the following structure:
 a. a triple-stranded extended helix
 b. a beta-pleated sheet
 c. a right-handed alpha-helix
 d. a left-handed alpha-helix
 e. a mixture of a

hiufwsiuefbwe   36   1 Reply

jana_akkari

Which of the following statements about lipids is false?

Which of the following statements about lipids is false?

Which of the following statements about lipids is false?
 a. The lipids found in biological systems are either hydrophobic or amphipathic.
 b. Lipids represent highly reduced forms of carbon.
 c. Lipids are highly soluble in water.

ahh_risa   87   1 Reply

bbebe

Fatty acids that are saturated:

Fatty acids that are saturated:

Fatty acids that are saturated:
 a. have an even number of carbon atoms
 b. have single bonds between all carbon atoms
 c. have an odd number of carbon atoms
 d. have double bonds between some carbon atoms
 e. none of the ab

Griffinw42   57   1 Reply

Findingskate61

Which of the following two fatty acids are the most common saturated fatty acids in nature?

Which of the following two fatty acids are the most common saturated fatty acids in nature?

Which of the following two fatty acids are the most common saturated fatty acids in nature?
 a. lauric acid (dodecanoic acid) and stearic acid (octadecanoic acid)
 b. myristic acid (tetradecanoic acid) and palmitic acid (hexadecanoic acid)

bdiddydog   36   1 Reply

yuhiyuhi

Which of the following statements about fatty acids is true?

Which of the following statements about fatty acids is true?

Which of the following statements about fatty acids is true?
 a. The double bonds found in fatty acids are nearly always in the cis configuration.
 b. The configuration around the double bond in fatty acids causes a bend or kink in the fat

Miller123   47   1 Reply

Lex_Lex21

Triacylglycerols are: (Multiple Choice)

Triacylglycerols are: (Multiple Choice)

Triacylglycerols are:
 a. the fatty acids found only in microorganisms
 b. fatty acids with highly oxidized carbons
 c. a major energy reserve for animals
 d. found only in animals
 e. all of the above

stalmoney   37   1 Reply

ericpie13

While many diets call for reduced intake levels of cholesterol, the plant sterols such as ...

While many diets call for reduced intake levels of cholesterol, the plant sterols such as ...

While many diets call for reduced intake levels of cholesterol, the plant sterols such as stigmasterol, which are very similar in structure to cholesterol, are not restricted. One of the reasons for the lack of strictures on plant sterols is:
 

Greenspotsock   46   1 Reply

jjdjd j

The glycosphingolipids, which are important components of muscle and nerve cells, are distinguished ...

The glycosphingolipids, which are important components of muscle and nerve cells, are distinguished ...

The glycosphingolipids, which are important components of muscle and nerve cells, are distinguished by having:
 a. one or more sugar residues in beta-glycosidic linkage at the 1-hydroxyl position of a ceramide
 b. a diphosphatidylglycerol

Pooh bear   29   1 Reply

Kanashaea

The major energy reserves in animals are:

The major energy reserves in animals are:

The major energy reserves in animals are:
 a. glycerophospholipids
 b. terpenes
 c. sphingolipids
 d. triglycerides
 e. cholesterol

redheadprincess   25   1 Reply

jeooncdaoc

The primary function of the dolichyl phosphates is to:

The primary function of the dolichyl phosphates is to:

The primary function of the dolichyl phosphates is to:
 a. serve as intermediates for cholesterol biosynthesis
 b. to carry carbohydrate units in the biosynthesis of glycoproteins
 c. form part of the water-insoluble waxes
 d. fo

adamsnaya   25   1 Reply

neontoast91

A 1,2-diacylglycerol that has a phosphate group esterified at carbon atom 3 of the glycerol is a: ...

A 1,2-diacylglycerol that has a phosphate group esterified at carbon atom 3 of the glycerol is a: ...

A 1,2-diacylglycerol that has a phosphate group esterified at carbon atom 3 of the glycerol is a:
 a. cardiolipin
 b. tristearin
 c. sphingomyelin
 d. terpene
 e. glycerophospholipid

adamsnaya   47   1 Reply

ravindergill185

Attachment of long-chain polyisoprenoid groups to membrane proteins typically occurs:

Attachment of long-chain polyisoprenoid groups to membrane proteins typically occurs:

Attachment of long-chain polyisoprenoid groups to membrane proteins typically occurs:
 a. randomly throughout the protein
 b. at the amino terminus
 c. at the amino groups of internal lysine residues
 d. at a cysteine residue nea

Abessesen   23   2 Replies

Abessesen

Certain proteins are covalently linked to lipid molecules in membranes. These attachments include: ...

Certain proteins are covalently linked to lipid molecules in membranes. These attachments include: ...

Certain proteins are covalently linked to lipid molecules in membranes. These attachments include:
 a. amide-linked myristoyl anchors
 b. thioester-linked fatty acyl anchors
 c. thioether-linked prenyl anchors
 d. amide-linked gl

Miller123   32   1 Reply

Lex_Lex21

In experiments designed to explore whether there is protein transverse asymmetry in membranes, it ...

In experiments designed to explore whether there is protein transverse asymmetry in membranes, it ...

In experiments designed to explore whether there is protein transverse asymmetry in membranes, it was shown that when trypsin was used to treat intact erythrocytes, the carbohydrate groups of the transmembrane protein glycophorin were released from t

98lindsey   30   1 Reply

NILLABRO

The term phase transition as applied to lipid bilayers involves the conversion of a gel to a liquid ...

The term phase transition as applied to lipid bilayers involves the conversion of a gel to a liquid ...

The term phase transition as applied to lipid bilayers involves the conversion of a gel to a liquid crystalline phase. The Tm or transition temperature would be decreased by:
 a. an increase in the average chain length of the component phosphol

rachelkimq   30   1 Reply

hsprouse