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Flashcards in Midterm 1 Old Exams/Study Questions Deck (37):
1

1. Which of the following amino acids would you find in a “turn” of the polypeptide backbone?
a. Tryptophan
b. Proline
c. Phenylalanine
d. Histidine
e. glycine
f. b and e

f. b and e (proline and glycine)

2

What kind of noncovalent interaction is typified by interactions between two molecules that
are so close together that they can experience weak attractive forces bonding them together?

van der Waals forces

3

3. A disulfide bond in a protein usually exists:

outside the cell because the environment outside the cell is oxidizing

4

4. Which of the following is not a macromolecule formed by polymerization?
a. proteins
b. lipids
c. polynucleotides
d. polysaccharides
e. DNA

b. lipids

5

5. Monomeric proteins do not contain a:
a. primary structure.
b. secondary structure.
c. tertiary structure.
d. quaternary structure.

d. quarternary structure

6

6. Which amino acid is most likely to be found in the core of a protein?
a. methionine
b. asparagines
c. serine
d. threonine
e. glutamic acid

methionine

7

7. The α-helix is characterized by orientation of ______ the molecular axis.
a. H bonds parallel to
b. H bonds perpendicular to
c. ionic bonds parallel to
d. ionic bonds perpendicular to
e. peptide bonds perpendicular to

H bond parallel to

8

8. Which amino acid is most likely located on the surface of a native protein in aqueous solution?
a. Phenylalanine
b. Isoleucine
c. Asparagine
d. Tryptophan
e. None of the above

c. Asparagine

9

9. Which of the following is not a model organism?
a. Mice
b. Fruit fly
c. Roundworm
d. Yeast
e. Human
f. Bacteria

e. human

10

10. When two atoms differing in electronegativity are joined in a covalent bond, then the
a. electrons are shared equally between the atoms.
b. bond is nonpolar.
c. resulting compound is devoid of any dipole moment.
d. atom with the greater electronegativity attracts the bonded electrons more.

d. atom with greater electronegativity attracts the bonded electrons more

11

12. Which of the following is a mechanism for regulating protein activity?
a. proteolytic processing
b. phosphorylation/dephosphorylation
c. ligand binding
d. b and c
e. all of the above

e. all of the above

12

13. Which are amino acids used in the kinase/phosphatase switch?
a. serine
b. threonine
c. tyrosine
d. a and b
e. a, b and c

e. serine, threonine, and tyrosine

13

14. What kind of enzyme adds phosphate groups to enzymes for the purpose of activating or
deactivating them?
a. phosphatases
b. protein kinases
c. flippases
d. glycosyltransferases

protein kinases

14

-- are mirror images. They have similar chemical properties but different
biological properties.

Stereoisomers

15

What kind of enzyme adds phosphate groups to proteins for the purpose of activating or deactivating them?

protein kinases

16

2. Following amino acids are used in a kinase/phosphatase switch except:
a. serine
b. threonine
c. tyrosine
d. glycine
e. none of these above

d. glycine

17

3. Which of the following can activate a GTPase?
a. GDI
b. GDP
c. GAP
d. GEF
e. GTPase

d. GEF

18

4. All of the following are pyrimidines except:
a. adenine
b. cytosine
c. thymine
d. uracil
e. none of these above

a. adenine

19

5. Which of the following is a mechanism for regulating protein activity?
a. proteolytic processing
b. phosphorylation/dephosphorylation
c. ligand binding
d. all of the above

d. all of the above

20

6. Which of the following is/are required for the release of a folded protein from a chaperonin?
a. assistance of GroES
b. hydrolysis of ATP
c. GroEL in a tight conformation
d. GroES in a relaxed conformation
e. a and b

e. a and b

21

7. Which of the following is a building block of DNA?
a. Tryptophan
b. Proline
c. Phenylalanine
d. Uracil
e. none of these above

e. none of these

22

9. Which of the following has the weakest bond strength?
a. phosphoanhydride bond
b. phosphodiester bond
c. peptide bond
d. covalent bond
e. ionic bond

ionic bond

23

2. A(n) cell has membrane-bound organelles.

Eukaryotic

24

is the smallest particle of an element.

Atom

25

1. Which of the following statements are correct?
I. An atomic nucleus typically contains proton(s) and neutron(s)
II. An atom by itself has more electrons than protons.
III. The number of neutrons determines whether an atom is stable or reactive
IV. Hydrogen bonds are weak and can be broken by heat, yet they contribute significantly to the
specificity of interactions between macromolecules.
V. Atom is the smallest particle of an element.
a. I and II
b. II and III
c. I, III, and IV
d. I, IV, and V
e. I, II, IV, and V

d. I, IV, and V

26

3. Which of the following statements are correct?
I. The hereditary information of a cell is passed on by its proteins.
II. Bacterial DNA is found in the nucleus.
III. All cells of the same organism have the same number of chromosome (with the exception of
egg and sperm cells).
IV. The cytosol of a eukaryotic cell contains membrane-enclosed organelles.
a. I and II
b. II and III
c. III and IV
d. II and IV
e. II, III, and IV

c. III. All cells of the same organism have the same number of chromosome (with the exception of
egg and sperm cells).
IV. The cytosol of a eukaryotic cell contains membrane-enclosed organelles.

27

Tryptophan repressor is inactive when it is bound to a molecule of tryptophan.
A. True
B. False

false

28

The active site of an enzyme usually occupies only a -- of the enzyme surface.

small fraction

29

8. Which of the following amino acid would you expect to find more often near the center of a
folded globular protein in the cell cytoplasm?
a. serine
b. lysine
c. histidine
d. valine
e. tyrosine

valine

30

10. Which DNA pyrimidine forms two H bonds with its partner in the other DNA strand?
a. adenine
b. cytosine
c. guanine
d. uracil
e. none of these above

none of these

31

11. Disulfide bonds help to stabilize the three-dimensional structure of proteins. Which amino
acid is involved in the formation of disulfide bonds?
a. lysine
b. aspartic acid
c. asparagine
d. proline
e. None of these above

none of these

32

12. What kind of enzymes remove phosphate groups on the surface of their substrate proteins for
the purpose of activating or deactivating the substrates?
A. carboxypeptidase
B. protein kinases
C. flippases
D. glycosyltransferases
E. None of these above

none of these

33

An amphipathic molecule has
a. both positive and negative components.
b. both hydrophilic and hydrophobic properties.
c. only nonpolar covalent bonds.
d. a and b
e. b and c

both hydrophilic and hydrophobic

34

16. Following amino acid is used in a kinase/phosphatase switch:
a. alanine
b. threonine
c. proline
d. glycine
e. none of these above

threonine

35

Which of the following can inactivate a small GTPase?
a. GTP
b. GDP
c. GAP
d. GEF
e. DnaK

GAP

36

Which of the following is purine?
a. adenine
b. cytosine
c. thymine
d. uracil
e. none of these above

adenine

37

19. Which of the following is a mechanism for regulating protein activity?
a. proteolytic processing
b. phosphorylation/dephosphorylation
c. translation
d. all of the above
e. a and b

proteolytic processing
phosphorylation/dephosphorylation