Exam 2 Test Questions

Question 1

From the list below which functional group is the most oxidized?
A.	hydroxyl
B.	carboxyl
C.	methyl/methylene
D.	carbonyl
E.	carbon-carbon double bond

Answer 1

B. carboxyl

Question 2

Consider the compound below:
O
||
H3C — C —-OH

Which of the following statement(s) is(are) true?
I. This compound has polar and nonpolar groups
II. This compound will donate hydrogen bonds, but cannot accept them
III. This compound will accept hydrogen bonds, but cannot donate them
A. only I is true
B. only II is true
C. only III is true
D. I and II are true
E. I, II, and III are true

Answer 2

A. only I is true

Question 3

The major organic base in this course
A.	has a positive charge at high pH
B.	has a positive charge at low pH
C.	is the amino group
D.	A and B
E.	B and C

Answer 3

E. B and C

Question 4

All amino acids
A. contain a constant backbone and a nonpolar side chain
B. contain a variable backbone and a constant side chain
C. contain an amino group, a central carbon, and a carboxyl(ic acid) group
D. have acidic or basic side chains
E. have the side chain covalently bonded directly to the carbon atom of the carboxylic acid group

Answer 4

C. contain an amino group, a central carbon, and a carboxyl(ic acid) group

Question 5

Which of the following is an example of an oxidation reaction?
A. the conversion of elemental chlorine to chloride ions
B. the conversion of an Fe3+ ion to an Fe2+ ion
C. the conversion of a methyl group (CH3) to a carboxylic acid (COOH) group
D. the conversion of Na+ ions to elemental Na0
E. the conversion of a carboxylic acid (COOH) group to a carbonyl (CO) group

Answer 5

C. the conversion of a methyl group (CH3) to a carboxylic acid (COOH) group

Question 6

Which of the following is NOT true about the hydrophobic effect?
A. It is responsible for the folding of proteins.
B. It is responsible for the association of phospholipids to form bilayers.
C. It leads to an association between a nonpolar group and another nonpolar group.
D. It forms the little fat globules found in chicken soup.
E. All of the above are true.

Answer 6

E. All of the above are true.

Question 7

Cells are full of biological polymers because
A. polymers are more stable than the monomers (that is, polymers predominate at equilibrium)
B. cells use energy to synthesize polymers from monomers
C. polymers have a large activation energy barrier to degradation
D. A and B
E. B and C

Answer 7

E. B and C

Question 8

A solution with an H+ ion concentration of 7 x 10^-7 
A.	is neutral
B.	is basic
C.	has a pH greater than 7
D.	has a pH less than 7
E.	will donate electrons to amino groups

Answer 8

D. has a pH less than 7

Question 9

Which of the following is NOT true about complex carbohydrates?
A. they are large polymers of glucose
B. they include the most abundant biological material on earth
C. they are only used for energy storage
D. they include both linear and branched molecules
E. all of above are true

Answer 9

C. they are only used for energy storage

Question 10

Which of the following is true about the ends of polypeptides and nucleic acids?
A. the ends of a polypeptide are named after the amino and carboxylic acid ends of the amino acid monomers
B. the ends of a nucleic acid are named after the 4’ and 2’ atoms in the ribose/deoxyribose sugar of the nucleotide monomer
C. the sequence of a polypeptide is usually written from the carboxyl (C) to the amino (N) end
D. the sequence of a nucleic acid is usually written from the 3’ to the 5’ end
E. none of the above

Answer 10

A. the ends of a polypeptide are named after the amino and carboxylic acid ends of the amino acid monomers

Question 11

Two polypeptides have very different sequences; they
A. are the same protein, but from different species (like human vs. pig insulin)
B. are different proteins (like insulin vs. keratin)
C. will both fold with the nonpolar amino acid side chains mostly on the outside of the folded protein
D. A and B
E. A and C

Answer 11

B. are different proteins (like insulin vs. keratin)

Question 12

Consider the compound below:
O H H H H H H H H H H H H H H H
|| | | | | | | | | | | | | | | |
O-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-CH3
| | | | | | | | | | | | | | |
H H H H H H H H H H H H H H H
Which of the following statements is true?
A. The methyl group on the right end of this compound would donate an H+ at high pH
B. The carboxylic acid group on the left end of this compound would gain an H+ to become electrically neutral at high pH
C. This compound will make ester bonds to glycerol in triglycerides and phospholipids
D. This compound is a cis unsaturated fatty acid
E. This compound is a trans unsaturated fatty acid

Answer 12

C. this compound will make ester bonds to glycerol in triglycerides and phospholipids

Question 13

If “Small TeChies are pyrates”
A.	T and C are purines
B.	T and C are pyrimidines
C.	T and C are polar
D.	T base pairs with C
E.	none of the above

Answer 13

B. T and C are pyrimidines

Question 14

Which of the following statements about heterochromatin and euchromatin is true?
A. Euchromatin is usually located in the periphery of the nucleus.
B. Heterochromatin has fewer RNA products of transcription than euchromatin.
C. Heterochromatin includes the DNA that is actively being transcribed.
D. Euchromatin appears condensed and dark in the electron microscope.
E. None of the above are true.

Answer 14

B. Heterochromatin has fewer RNA products of transcription than euchromatin.

Question 15

Prokaryotic cells
A. have cell walls made of peptidoglycan (or pseudopeptidoglycan)
B. live only above ground
C. include only bacteria
D. are minor components of the biosphere
E. are generally large (100 micrometers to 1 millimeter)

Answer 15

A. have cell walls made of peptidoglycan (or pseudopeptidoglycan)

Question 16

Which of the following statements about ribosomes is true?
A. The sequence of the ribosomal RNA (rRNA) determines the sequence of amino acids in a polypeptide.
B. Ribosomes making proteins for export (secretion) are associated with the membranes of the Golgi complex.
C. The rRNA component catalyzes the formation of peptide bonds in polypeptides.
D. All the ribosomes in the cell are associated with the rough endoplasmic reticulum.
E. The protein component catalyzes the formation of ester bonds in polypeptides.

Answer 16

C. The rRNA component catalyzes the formation of peptide bonds in polypeptides.

Question 17

Which of the following is NOT true about nuclear pores?
A. They are the site where ribosomes are assembled.
B. They cross through both the inner and outer membrane of the nuclear envelope.
C. They are the site where RNA passes from nucleus to cytoplasm.
D. They contain proteins that regulate traffic between the nucleus and cytoplasm.
E. They are visible in electron micrographs as gaps in the nuclear envelope containing some lightly staining material.

Answer 17

A. They are the site where ribosomes are assembled.

Question 18

The rough endoplasmic reticulum
A. is continuous with the outer bilayer of the nuclear envelope
B. will be prominent in cells making lots of proteins for secretion, like pancreatic cells and plasma cells
C. is discontinuous with the smooth endoplasmic reticulum
D. A and B
E. A and C

Answer 18

D. A and B

Question 19

Which of the following is(are) dispersed throughout the volume of the nucleus?
A.	nuclear lamina
B.	nucleolus
C.	nuclear matrix
D.	A and B
E.	A and C

Answer 19

C. nuclear matrix

Question 20

The smooth endoplasmic reticulum
A. consists of a series of interconnected flattened sacs
B. is the site for synthesis of proteins destined for export (secretion)
C. is the site of phospholipid, cholesterol and steroid synthesis
D. A and B
E. B and C

Answer 20

C. is the site of phospholipid, cholesterol and steroid synthesis

Question 21

Recycling old organelles
A. occurs when a secondary lysosome containing the old organelle fuses with a primary lysosome
B. occurs when an autophagosome containing the old organelle fuses with a primary lysosome
C. is promoted by overeating
D. A and B
E. B and C

Answer 21

B. occurs when an autophagosome containing the old organelle fuses with a primary lysosome

Question 22

The trans face of the Golgi complex
A. is the entrance door of the Golgi
B. is the site where vesicles containing proteins from the ER enter the Golgi
C. is the side of the Golgi towards the nucleus
D. is the side of the Golgi where secretory and lysosomal vesicles leave
E. none of the above

Answer 22

D. is the side of the Golgi where secretory and lysosomal vesicles leave

Question 23

The secretory pathway for proteins includes which of the following steps in order:
A. SER, transport vesicle, trans Golgi, cis Golgi, secretory vesicle
B. RER, transport vesicle, cis Golgi, trans Golgi, secretory vesicle
C. RER, transport vesicle, trans Golgi, cis Golgi, secretory vesicle
D. SER, RER, transport vesicle, cis Golgi, trans Golgi, secretory vesicle, lysosome
E. RER, secretory vesicle, trans Golgi, cis Golgi, transport vesicle

Answer 23

B. RER, transport vesicle, cis Golgi, trans Golgi, secretory vesicle

Question 24

Primary lysosomes
A. Contain hydrolytic enzymes that are best segregated from the rest of the cell
B. Will fuse with exosomes containing particles brought into the cell by exocytosis
C. Bud off from the cis Golgi
D. A and B
E. A and C

Answer 24

A. contain hydrolytic enzymes that are best segregated from the rest of the cell

Question 25

Endocytosis mediated by receptors for LDL
A. is a form of bulk transport across the membrane
B. helps keep the lipid concentrations in the blood low
C. involves uptake of both LDL’s and food particles
D. A and B
E. B and C

Answer 25

D. A and B

Question 26

If you are a woman,
A. your mitochondrial DNA can be passed to your son
B. your mitochondrial DNA can be passed to your daughter
C. your mitochondrial DNA was inherited from your mother
D. your mitochondrial DNA was inherited from your father
E. all of the above, except D

Answer 26

E. all of the above, except D

Question 27

Mitochondria
A. have three membranes
B. are responsible for the production of reduced organic compounds
C. use O2 to accept electrons from the oxidation of organic compounds
D. A and B
E. B and C

Answer 27

C. use O2 to accept electrons from the oxidation of organic compounds

Question 28

Microfilaments in the cytoskeleton
A. are thinner than intermediate filaments and microtubules
B. play important roles in cell movement, including amoeboid movement
C. form the nuclear pores
D. A and B
E. A and C

Answer 28

D. A and B

Question 29

Going from outisde to inside, the order of membranes and compartments in the mitochondria are
A. outer membrane, inner membrane, intermembrane space, matrix
B. outer membrane, intermembrane space, inner membrane, matrix
C. outer membrane, matrix, intermembrane space, inner membrane
D. matrix, inner membrane, intermembrane space, outer membrane
E. outer membrane, intermembrane space, matrix, inner membrane

Answer 29

B. outer membrane, intermembrane space, inner membrane, matrix

Question 30

Mitochondria and chloroplasts share many features. Which of the following features do they NOT share?
A. They both produce energy by oxidizing reduced carbon compounds
B. They were both formerly free-living prokaryotes
C. They both have multiple membranes
D. They both have one membrane that is highly folded to increase its surface area
E. They both contain some DNA

Answer 30

A. they both produce energy by oxidizing reduced carbon compounds

Question 31

Chloroplasts
A. store energy in oxidized carbon compounds, which is released on reduction
B. store energy in reduced carbon compounds, which is released on oxidation
C. oxidize CO2 to make compounds that have lots of H’s
D. reduce CO2 to make compounds that have lots of O’s
E. none of the above

Answer 31

B. store energy in reduced carbon compounds, which is released upon oxidation

Question 32

The so-called “9+2 arrangement” of microtubules means that \_\_\_\_ pair(s) of microtubules are found on the outside and \_\_\_\_\_ pair(s) (be careful) are found in the center of \_\_\_\_\_\_\_\_.
A.	9, 2, flagella but not cilia
B.	9, 11, cilia but not flagella
C.	9, 1, nuclei
D.	2, 9, both cilia and flagella
E.	9, 1, both cilia and flagella

Answer 32

E. 9, 1, both cilia and flagella

Question 33

Intermediate filaments in the cytoskeleton
A. are intermediate in thickness between microfilaments and microtubules
B. form the nuclear lamina
C. play important roles in cell movement, such as muscle contraction
D. A and B
E. A and C

Answer 33

D. A and B