CORRECT ANSWERS
What type of bond connects nucleotides? - Answer-Hydrogen bonds and
phosphodiester bonds
Which of the following statements about the structure of DNA is incorrect?
A) One complete turn requires 3.4 nm and 10 base pairs.
B) The backbones of each strand run in opposite directions relative to each other.
C) Each pair of nucleotides is held together by three hydrogen bonds.
D) The width of the molecule is a constant 2 nm. - Answer-C
What functional role is the three dimensional structure of DNA likely to accomplish? -
Answer-Very long molecules of DNA can be packed into small spaces
The genetic material must be able to contain an infinite amount of information. -
Answer-True
Hydrogen bonding is the primary chemical bond holding a strand of DNA together. -
Answer-False
The backbones of the two DNA strands in a double helix run in opposite directions
(one 5'-3' left to right, the other 5'-3' right to left). - Answer-True
Which statement is false?
A) RNA and DNA are both composed of nucleotides joined by phosphodiester bonds.
B) RNA and DNA both have secondary and tertiary structure.
C) RNA is always single stranded while DNA is always double stranded.
D) A and B are both false.
E) None of these (A, B and C are all true statements) - Answer-C
Which of the following is NOT a component of plasma membranes?
A. glycosylated proteins
B. phospholipids
C. glycolipids
D. glycosylated nucleic acids
E. cholesterol - Answer-D
, Which of the following is NOT true of the plasma membrane?
A. It is composed of an extracellular and intracellular layer of phospholipids.
B. The extracellular and intracellular layers or leaflets are highly symmetrical.
C. The membrane contains peripheral proteins.
D. Integral proteins span through the membrane.
E. The membrane contains glycolipids and glycoproteins. - Answer-B
N-linked glycosylation is the attachment of a carbohydrate to a nitrogen atom (amide
nitrogen of asparagine (Asn) residue of a polypeptide), while O-linked glycosylation is
the addition of a string of sugars to the oxygen atom of serine or threonine side chains
of polypeptides. - Answer-True
The process of covalently attaching a carbohydrate to a protein or lipid is called: -
Answer-Glycosylation
Which requires energy facillitated or passive diffusion? - Answer-Passive diffusion
. Exocytosis is the process by which material from inside of the cell is packaged into
vesicles and excreted into the extracellular medium. - Answer-True
The following solutes have very low permeability through the plasma membrane -
Answer-Charged polar molecules and macromolecules
. Water can freely diffuse through animal cell membranes - Answer-False
In eukaryotes, cytosol and endomembrane system work together to synthesize most
lipids. This process occurs - Answer-In the cytosoloic leaflet of the smooth ER
. Scientists unearth a Wooly Mammoth from the Siberian Ice Sheath and discover that a
eukaryotic "amoeba"-like cell is still alive. Which component of the cell membrane might
contribute to maintaining the fluidity of plasma membranes under freezing conditions? -
Answer-high levels of unsaturated fatty acyl tails within the lipid bilayer
A substrate binds an enzyme as a signal molecule binds a - Answer-Receptor
During exposure to elevated glucose, a yeast cell's membrane glucose transporters will
rapidly increase so the cell can import glucose. Which would represent the signal for the
yeast cell? - Answer-Glucose
The production of second messengers in signal transduction offers at least two
advantages, speed and - Answer-Amplification
A hormone binds a receptor and activates the cAMP signal transduction pathway
ultimately leading to the cell response. Which of the following is NOT a likely