Download defend your answer in 1

Biol 205 Spring 2008 Quiz 1 20 pts. NAME______________________
Version A Question about DNA acronym not counted
1. (8 pts) True/False 1 pt each. Choose false if any part of the statement is incorrect.
false A covalent bond is likely to be polar when it is between two atoms that are both very strong
electron acceptors
false If a species genome is divided into 10 chromosomes, that means that all of the genetic
information for the species is contained in 5 different double-stranded DNA polymers.
true One of the reasons for studying simple, single-celled organisms (such as E. coli and yeasts) is
that humans share some of their genes with these organisms.
false The primary difference between a cell and a virus particle is that the latter does not include a
lipid bilayer. Many animal viruses have a membrane coat derived from the host cell plasma
membrane
false The D in DNA refers to a missing carboxyl group on the nucleotide monomer unit.
false Hydrogen bonds connect the individual monomer units within a single strand (polymer) of
nucleic acid.
true If a hydrophobic amino acid found in a protein residing in the cytosol is replaced with an amino
acid with a charged side group, the protein will likely turn inside out.
2. (3 pts.) Examine the diagram shown below which was taken from your textbook. Which sentence
or sentences is(are) true with respect to the activity of a catalyst?
A catalyst will effectively STATEMENT I is correct. All other statement incorrect.
I. Decrease energy level a with no effect on energy levels b or c
II. Decrease energy levels a and c
III. Decrease energy level a and increase c
IV. Increase c while a and b remain the same
V. This reaction would not typically require a catalyst, but, if it did, statement I. would apply
VI. None of the above are correct
NOW: defend your answer in 1-2 sentences (maximum) using proper terminology.
An enzyme speeds up the rate of a reaction by lowering energy level a which is referred to
as the energy of activation. It has no affect on the energy level of the resulting products
1
3. (5 pts.) For each of the following sentences, fill in the blanks with the best word or phrase selected
from the list below. Not all words or phrases will be used; each word or phrase should be used only
once.
The α helices and β sheets are examples of protein secondary structure. A
protein such as hemoglobin, which is composed of more than one protein
subunit, has quaternary structure. A protein’s amino acid sequence is known as
its primary structure. A protein domain is the modular unit from which many
larger single-chain proteins are constructed. The three-dimensional
conformation of a protein is its tertiary structure.
allosteric
domain
helix
ligand
primary
quaternary
secondary
tertiary
4. (4 pts.) a. What kind of secondary structure is present in the polypeptide backbone shown below?
β (beta) sheet
b. What kind of bonds stabilize this seconday structure (write out full name) hydrogen bonds
c. Indicate one example of this type of bond on the figure below: use a dashed line, circle the atoms
involved, and label with a B circle H bonded to N and O of carbonyl
d. Circle the atoms involved in a peptide bond and label with a P:
circle adjacent N and carbonyl C only
Question
(pts.)
1. (8pts)
2. (3 pts)
3. (5 pts)
4. (4 pts)
Total (20)
2
Score