Florida National University Biochemistry Multiple Choice Questions

0.25 PointsThe primary difference between the amino acids commonly found in proteins is in their:

1. number of asymmetric carbons.
2. number of carbonyl groups.
3. R or variable groups.
4. number of potassium groups.
5. number of phosphate groups.

0.25 PointsFigure 3-1

The products of the process in the accompanying figure are:

1. enzymes.
2. amino acids.
3. representative of a glycoside linkage.
4. molecules of glycerol.
5. monosaccharides.

0.25 PointsUnlike lipids, hydrophilic functional groups typically contain ____ atoms, which make them more soluble in water.

1. carbon
2. oxygen
3. nitrogen
4. phosphate
5. hydrogen

0.25 PointsFigure 3-2

In the accompanying figure, hydrophobic interactions would occur between the R groups of which two amino acids?

1. 3 and 6
2. 2 and 4
3. 2 and 5
4. 1 and 4
5. 3 and 5

0.25 PointsMatch the molecule with the appropriate word or phrase.PromptsSubmitted Answers

1. Question 8most are nonpolarChoose a match
2. Question 8celluloseChoose a match
3. Question 8consist of monomers having 20 different typesChoose a match
4. Question 8a beta-pleated sheet is one typical structureChoose a match
5. Question 8monomers are joined by a glycosidic linkageChoose a match
6. Question 8contains purines and pyrimidinesChoose a match
7. Question 8may contain thymineChoose a match
8. Question 8cholesterolChoose a match

0.25 PointsGlucose and fructose are ____ because they have identical molecular formulas but their atoms are arranged differently.

1. structural isomers
2. tertiary
3. geometric isomers
4. polar
5. enantiomers

0.25 PointsCarotenoids are composed of isoprene subunits.__________________

1. True
2. False

0.25 PointsAssume that the shaded portions of the molecule in the accompanying figure each represent different polypeptide chains. What does this represent?

1. an amino acid
2. a steroid hormone
3. a carotenoid
4. cellulose
5. the quaternary structure of a protein

0.25 PointsWhen we know what kinds of ____ are present in an organic compound, we can predict its chemical behavior.

1. functional groups
2. triacylglycerols
3. macomolecules
4. enzymes
5. proteins

0.25 PointsIdentify the levels of organization for protein molecules, and list the type(s) of bond(s) involved in establishing each structural level.

0.25 PointsIf you partially hydrogenate oleic acid, the resulting molecule most likely would:

1. become soluble in water.
2. lose a carbon atom.
3. contain more double bonds.
4. have a double bond changed from cis to trans.
5. lose a carboxyl group.

0.25 PointsAn amino group is weakly basic and includes a(n) ____ atom covalently bonded to two hydrogen atoms.

1. phosphate
2. nitrogen
3. sulfur
4. oxygen
5. carbon

0.25 PointsChitin is a polymer composed of N-acetyl glucosamine monomers.__________________

1. True
2. False

0.25 PointsWhat carbohydrate energy storage molecule is found in animal liver and muscle cells?

1. cellulose
2. starch
3. glycogen
4. a fatty acid
5. cholesterol

0.25 PointsFigure 3-1

What chemical process is represented in the accompanying figure?

1. condensation
2. dehydration synthesis
3. protein synthesis
4. denaturation
5. hydrolysis

0.25 PointsHow many carbon sugars are there in a pentose sugar?

1. six
2. eight
3. two
4. three
5. five

0.25 PointsAnalysis of a certain polymer shows that it contains phosphate groups, ribose groups, and pyrimidines. Based on this information, what statement best describes this compound?

1. It is RNA.
2. It is an inorganic compound.
3. It is a polypeptide.
4. It is DNA.
5. It is cylic AMP.

0.25 PointsWhat is the purpose of regulatory proteins?

1. To defend against foreign invaders
2. To store nutrients
3. To catalyze a specific chemical reaction
4. To strengthen and protect cells and tissues
5. To control the expression of specific genes

0.25 PointsAmyloplasts are organelles that store:

1. starch.
2. DNA.
3. lipids.
4. protein.
5. fat.

0.25 PointsWhat type of protein accelerates the thousands of different chemical reactions thattake place in an organism?

1. amino acid
2. transport protein
3. enzyme
4. regulatory protein
5. protective protein

0.25 PointsWhat group of molecules is represented in this structure?

1. polysaccharides
2. phospholipids
3. structural proteins
4. triacylglycerols
5. polypeptides

0.25 PointsSickle cell anemia is a genetic disease caused by the replacement of one amino acid in the hemoglobin molecule. This replacement changes the shape and function of the hemoglobin protein in dramatic ways, which can sometimes be lethal. How can the substitution of one amino acid lead to such drastic results?

0.25 PointsA molecule of a saturated triacylglycerol contains:

1. alternating single and double bonds between carbons in the fatty acid chains.
2. the maximum number of triple bonds between carbons in the fatty acid chains.
3. the maximum number of double bonds between carbons in the fatty acid chains.
4. the maximum number of hydrogen atoms in the fatty acid chains.
5. fatty acid chains with both amino and carboxyl groups.

0.25 PointsIf tyrosine and isoleucine undergo condensation, where does the new bond form?

1. Between carbon of the carboxyl group and the hydrogen of the amino group
2. Between carbon of the carboxyl group and the nitrogen of the amino group
3. Between carbon of the carboxyl group and the hydrogen of the R group
4. Between carbon of the R group and the nitrogen of the amino group
5. Between oxygen of the R group and the hydrogen of the amino group

0.25 PointsIdentify three functions of proteins other than enzymes and briefly discuss or describe each.

0.25 PointsA phosphate group is weakly acidic.__________________

1. True
2. False

0.25 PointsFigure 3-3

What type of connection exists between the atoms at the point labeled 1 in the accompanying figure?

1. peptide bond
2. hydrogen bond
3. glycoside linkage
4. disulfide bond
5. phosphodiester linkage

0.25 PointsFigure 3-2

In the accompanying figure, ionic bonds would form between the R groups of which amino acids?

1. 2 and 4
2. 1 and 3
3. 3 and 6
4. 4 and 6
5. 3 and 5

0.25 PointsA beta-pleated sheet is an example of a protein’s tertiary structure.__________________

1. True
2. False

0.25 PointsA(n) essential amino acid is one that the body cannot synthesize in sufficient amounts.__________________

1. True
2. False

0.25 PointsWhat substance is removed during a condensation reaction?

1. a polymer
2. a dimer
3. water
4. a carboxyl group
5. a hydrocarbon

0.25 PointsFigure 3-3

The molecular fragment (the G, U and A’s) represented in the accompanying figure is:

1. RNA.
2. ATP.
3. DNA.
4. a polysaccharide.
5. a nucleotide.

0.25 PointsThe following amino acid would be characterized as ____ based on the chemical properties of its side chain.

1. electrically charged
2. nonpolar
3. acidic
4. basic
5. hydrophilic

0.25 PointsWhat is the purpose of molecular chaperones?

1. To assist the folding of other molecular proteins
2. To transfer an amino acid
3. To straighten other molecular proteins
4. To attach a carboxyl group
5. To strengthen the tertiary structure of a protein

0.25 PointsWhat organic molecules is the primary structural component of cell membranes?

1. glycogen
2. cellulose
3. phospholipids
4. disaccharides
5. adenine triphosphate

0.25 PointsHow many electron pairs are shared between carbon 2 and 3 in the accompanying figure?

1. four
2. three
3. one
4. one and a half
5. two

0.25 PointsAt which level of protein structure are peptide bonds most important?

1. quaternary
2. tertiary
3. primary
4. secondary
5. globular

0.25 PointsWhen a nucleic acid undergoes hydrolysis, the resulting subunits are:

1. nucleotides.
2. amino acids.
3. monosaccharides.
4. fatty acids.
5. carotenoids.

0.25 PointsThe helical coil shape of an α-helix fibrous protein provides what type of property to that protein?

1. elasticity
2. water retention
3. heat tolerance
4. rigidity
5. strength

0.25 PointsCompare and contrast the structure, physical characteristics, and biological functions of two of the following: fats, steroids, and phospholipids.