This review is DUE at 10:30am, Monday, September 21st, 1998.
The text of your answers must be typed but any figures may be hand-drawn
The top of the first page of your answers must include both your typed and signed name Your signature indicates that you have completed this exam following the honor code. The top of each additional page should only contain your initials and the page number. You do not need to turn in the question sheets. This review is not timed. That said, it was designed to be completed in one hour and, with typing, should not take more than two.
The review contain sections where a scenario is provided and multiple questions are asked. All questions within that part are loosely related. Do Not apply information from one scenario to questions in the next scenario. Always briefly provide the logic behind your answer, except when specifically asked for single word answers. In all cases brevity is encouraged.
Once you have read any question your review period has begun. Until that time you are free to study and discuss all topics relating to this class. After that time I am the only person you may ask questions pertaining to this review.
Section I -- Very Short Answers
Each question in this section should be answered with one word or a short phrase (20pt total))
1)Place in size order, starting with the largest:
Band 3 protein, Nucleus, Ribosome, Thymine
2)Name one place a cell degrades proteins.
3)Name 2 phospholipids commonly found in biological membranes.
4)How many common amino acids are there?
5)Name the pyrimidines (full names).
6)Which base is unique to RNA?
7)Chose the word or words that correctly completes
the each of the following
phrases. Words can be used more than once.
a) genes are made of _________
b) ________ contain many membrane-bound organelles
c) enzymes are made of _________
d) ________ is/are found in the nucleus
e) ________ have a plasma membrane
f) ribosomes use ________ as a template to make proteins
g) yeast cells are ________
h) there are three kinds of ________ in eukaryotic cells
#1 parts A-G (25pt total)
The next set of questions refers to the DNA sequence that follows. Type the given DNA sequence on your answer sheet above your answers for #1.
The DNA sequence is eukaryotic. RNA polymerase binds at the 'X'
A) What is the region at X called? (2pt)
B) In this gene transcription starts 5 residues 3' of the RNA polymerase binding site. Write out the RNA sequence that will be transcribed. (4pt)
C) Briefly describe 3 types of mRNA processing that occur in the nucleus. (6pt)
D) On the mRNA sequence you wrote for 1B clearly label where translation will start by using the name of the first amino acid and an arrow. (4pt)
F)The 3' end of the sequence is where translation of this gene ends. How many residues does the peptide contain. (3pt)
G)Briefly describe 2 factors that effect mRNA stability. (6pt)
#2 parts A-E (30pt total)
In your research you have discovered a one-celled organism. Under the microscope it appears to have 'normal' organelles like endoplasmic reticulum and a nucleus but it also contains an organelle that has not been described in any text. You name the organelle the novellosome. Eager to secure your place in history you isolate a large quantity of the organelle and begin characterizing it.
A) As would be expected the novellosome is surrounded by a membrane. In general, what are the 2 main components of biological membranes and what are their roles? (5pt)
B) Would you predict that novellosome membranes contains cholesterol? (support your answer)(4pt)
C) In a typical biological membrane what is the function of cholesterol? (3pt)
SDS-PAGE showed that the novellosome has many associated proteins. You decide to characterize 5 of them (named pN, pO, pV, pE, and pL). Your first 5 experiments and their results follow. In each case the membranes referred to are the isolated novellosomes.
experiment 1: salt-wash the membranes and centrifuge to separate components into supernatant and membrane pellet.
results: Supernant Pellet
pN pE, pL, pO, pV
experiment 2: hypotonic lysis of membranes followed by centrifugation
to separate supernatant and membrane pellet
results: Supernatant Pellet
pV pE, pL, pN, pO
experiment 3: hypotonic lysis of membranes then salt-wash followed by centrifugation to separate supernatant and membrane pellet.
results Supernatant Pellet
pL, pN, pV pO, pE
experiment 4: membranes with or without added protease. Separate proteins by SDS-PAGE. See lanes 1 and 2 of diagram.
experiment 5: membranes treated with detergent. Half separated by SDS-PAGE, the other half treated with protease then separated by SDS-PAGE. See lanes 3 and 4 of diagram.
Diagram of SDS-PAGE results for experiments 4 and 5
D) SDS-PAGE separates proteins on the basis of what physical property? (3pt)
E) Using the above data, draw a diagram showing where each of the proteins are in the novellosome. Provide a brief description why you chose those positions. (15pt)
Section III (25pt total)
1) The #of possible RNA nucleotide
combinations> the # of tRNAs > the # amino acids
What does this imply about the genetic code and tRNA base-pairing? (5pt)
2) What is a common structural motif found in
N-terminal signal peptides.
Compare that level of protein structure with the level required for a signal patch. (5pt)
3) You are given a testtube containing 2ml of H2O and 2ml of olive oil. You then add pure ganglioside. Predict where it will end up. Include in your prediction the general parts of ganglioside and how they effect its localization. (5pt)
4) What is the signal hypothesis and what experiments supported cleavage? (5pt)
5) In order to obtain the most
information in the least amount of time scientists
should focus their time and energy on studying human cell lines.
Briefly explain why you agree or disagree with this statement. (5pt)