MT1 Flashcards
- Which of the following is defined as the tertiary structure of a protein?
a. the primary amino acid sequence
b. structural domains such as a DNA-binding domain
c. folded structures such as an α helix
d. structural features such as a turn
e. disulfide bonds
b)
13) Which of the following is an application of immunofluorescence microscopy?
A) Identifying which organelle or cellular compartment contains a particular protein.
B) Construction of three-dimensional images of structures smaller than 10 nm.
C) Identification of specific components of the immune system.
D) Visualization of the surface structures of a specimen.
E) Visualization of the natural fluorescence of a specimen under UV light.
e
14) You are working on a project that involves the direct observation of DNA molecules.
The microscope that would give you the best information at this time would be the
e
15) ________ improved the original light microscope in the late 1600s, allowing the
visualization of ________.
e
16) Which of the following is not an activated monomer? A) aminoacyl tRNA B) uracil triphosphate C) glucose-6-phosphate D) adenosine triphosphate E) none of the above
e
17) Lipid rafts are
A) regions where greater concentrations of sphingolipids are on the inner side of the
membrane.
B) regions not typically associated with signal transduction.
C) regions of the membrane that are high in sphingolipids, which facilitate
communication with the external environment of the cell.
D) rafts of lipids inside of the cell that serve to store energy.
E) important regions of membrane structure comprised of phospholipids.
c
19) Which of the following is a terpene? A) glycerol B) testosterone C) chitin D) vitamin A E) estrogen
d
22) Which of the following statements is true?
A) Unsaturated fatty acids are usually branched.
B) Fatty acids with 24 carbons are most common.
C) Hormones are unsaturated fatty acids.
D) Fatty acids are synthesized by the stepwise addition of three carbon units.
E) None of the above
e
23) Which of the following is not one of the six classes of lipids? A) steroids B) fatty acids C) terpenes D) triacylglycerols E) pectins
e
25) Cholesterol is a ________, which ________.
A) fatty acid; functions in energy storage
B) steroid; is the basis for many animal and plant hormones
C) steroid; is a component of eukaryotic membranes and the basis for many animal and
plant hormones
D) terpene; is the basis for many animal and plant vitamins
E) steroid; is a component of eukaryotic membranes
e
26) A general trend in the structure of many biomolecules is
A) that the order and bonding of monomers form the basis for the secondary and tertiary
structure of the polymer.
B) that four different monomers form the basis for the functional and structural properties
of each polymer.
C) that each class of biomolecule can form either fibrous or globular conformations
depending on the chemical conditions inside the cell.
D) that they are all soluble in water independent of the size of the polymer.
E) that each class of biomolecule forms one type of secondary structure independent of
the order of the monomers in the polymer.
a
27) The function of triglycerides is A) store information. B) to form semipermeable membranes. C) to transport substances in and out of cells. D) to store energy. E) Both B and C are correct.
d
28) Fatty acids are ________; they function in the cell as ________.
A) short chains of double-bonded carbon molecules; vitamins, cofactors, and storage
lipids
B) long, unbranched hydrocarbon chains with a carboxyl group at one end; building
blocks for other lipids
C) four-ringed hydrocarbon molecules; key components of membranes
D) short chains of double-bonded carbon molecules; storage lipids
E) short chains of double-bonded carbon molecules; vitamins and cofactors
b
30) Which of the following has the greatest number of O-glycosidic bonds? A) triacylglycerol B) 300 bp of DNA C) vitamin A D) glucose E) 300-subunit amylose
e
31) Which of the following accurately describes the structure of fibrous proteins?
A) Fibrous proteins are usually composed of either α helices or β sheets throughout the
molecule, giving them a highly ordered, repetitive structure.
B) Fibrous proteins have an extensive tertiary and quaternary structure that affects the
strength and elasticity of each fiber.
C) Fibrous proteins have a simple primary structure and very little secondary structure,
resulting in long, thin fibers.
D) Fibrous proteins usually contain a number of different domains with different
structural motifs.
E) Fibrous proteins are composed of an equal mixture of α helices and β sheets with
interconnecting looped segments.
a
33) Proline is referred to as the “helix breaker” because
A) it lacks a charged functional groups for ionic bonding.
B) it lacks the hydrogen atom needed for hydrogen bonding.
C) it is hydrophobic.
D) its only found in the L form, which is incompatible with helical protein structure.
E) it has a polar functional group.
b
37) You are researching a cytoplasmic protein associated with a nerve disorder. The
native form of the enzyme appears to be globular protein; however, when a sample of the
purified protein is treated with a chemical that reduces disulfide bonds, the enzymatic
activity decreases dramatically and multiple globular proteins can be detected in the
sample. What does this tell you about the protein?
A) The protein is most likely composed of α helices that are held together by disulfide
bonds.
B) The primary and secondary structure of the protein depends on disulfide bonds.
C) The primary structure of the protein contains multiple cysteine residues that are
hydrolyzed by the chemical reductant.
D) The protein is most likely composed of multiple polypeptide chains that are held
together by disulfide bonds.
E) The protein is most likely composed of β sheets that are held together by disulfide
bonds.
d
39) Which of the following statements about self-assembly is false?
A) The noncovalent interactions that drive supramolecular assembly processes are similar
to those that dictate the folding of individual protein molecules.
B) Self-assembly only occurs in structures composed of protein.
C) Molecular chaperones are sometimes required for the proper folding and assembly of
complex proteins.
D) Self-assembly requires specific chemical conditions.
E) All of the above
b
40) An enzyme synthesized in the laboratory is found to have little activity when
compared to the enzyme extracted from cell culture. Both enzymes were examined and
have identical amino acid composition. What is the best explanation for the lack of
activity of the synthesized enzyme?
A) The synthetic enzyme was not made of amino acids.
B) The van der Waals radius was altered during laboratory synthesis.
C) The synthesized enzyme was not folded correctly because molecular chaperones were
not present.
D) The ATP required for self-assembly was present in the cell extract but not in the
laboratory synthesis.
E) Denaturation of the synthesized enzyme was not complete.
c
42) Experiments by Stanley Miller in the 1950s demonstrated that the first organic
molecules on earth
A) were catalysts composed of simple amino acids.
B) most likely formed in an extraterrestrial environment and were deposited on earth via
asteroids.
C) were catalysts composed of simple amino acids and most likely formed in an
extraterrestrial environment and were deposited on earth via asteroids.
D) were nucleic acids such as RNA and DNA.
E) could have formed abiotically in a reducing atmosphere containing hydrogen,
methane, ammonia, and water vapor.
e
43) The size range of most plant and animal cells is A) 1—10 nm. B) 1—5 μm. C) 0.1—0.5 mm. D) 50—100 mm. E) 10—50 μm.
e
