BIOL309 Final: Biol 208 Final Exam Notes

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cerisemole687

28 Dec 2011

School

University of Waterloo

Department

Biology

Course

BIOL309

Professor

Kyra Jones

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Document Summary

C-g bond has 3 h bonds while a-t has 2 h bonds between. Single-stranded dna absorbs uv light more strongly because no longer have stacking interactions between bases. Rna is more susceptible to degradation by ph. Rna secondary structures aid in mediating trna structure, transcriptions terminators, mrna stability and controlling gene expression. All dna strands are extended in the 5" 3" direction (requires 3" oh primers) while rna does not need a primer. B helix "normal", right-handed, 1 turn per 10bp. A helix lower water content, right-handed, 1 turn per 11 bp. Z helix cg, high salt, left-handed, irregular structure topoisomerases responsible for supercoiling of dna. Rna polymerases do not bind to dna promoter, called an operon directly and require certain transcription. Transcription is carried out by rna polymerase factors. Rna p"s bind to promoter and recognize a specific site downstream. Mrna contains 5" and 3" utr as well as exons. How are mutants created? (dna replication, mutagens, transposons)

Related Questions

1. The level of protein structure that is stabilized primarilyby non-covalent interactions between the side chains within asingle polypeptide chain is refered to as its:

A) primary structure

B) secondary structure

C) tertiary structure

D) quaternary structure

E) none of the above

2. Collagen, a strong fibrous protein found in connectivetissue, bone, and the extracellular matrix, has a structure inwhich three left-handed helices wind around each other to form aright-handed triple helix. The primary structure of collagen has arepeat unit of -(Gly-X-Pro)- Which of the following bonds stabilizethe collagen triple helix? (mark all that apply)

A) Hydrogen bonds between hydroxyproline residues

B) Hydrogen bonds between N-H and C=O

C) Ionic bonds between amino acid side chains

D) Hydrogen bonds between charged amino acids

3. The non-covalent forces that stabilize the Beta-strandconformation of peptides include:

A) H-bonds between amide C=O and amide NH

B) Van der Waals packing between the peptide backbone atoms

C) Van der Waals packing due to side chain interdigitation

D) Only A and B above

E) None of the above

4. What is the approximate length difference of a 22-kDasingle-stranded ?-helical protein segment vs. a 22-kDasingle-stranded ?-strand protein segment? Assume a mean residuemass of 110 Da. Show work.

5. Circular dichroism measurements have shown that the peptidebackbone of poly-l-lysine (KKKKKKK) adopts a random coilconformation at pH 7.0, but becomes ?-helical as the pH is raisedabove 10. This observation is known as the

magentaotter572

Hydrogen bonds can form with bases on the opposite DNA strands in the double helix, or between the bases and H2O in the single stranded conformation. Considering that the double helix is the most stable conformation in water, how does this observation support the conclusion that base stacking contributes more to helix stability than interbase hydrogen bonding?

Question 1

What type of bonding underlies base-pairing between DNA and RNA nucleotides?

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Question 2

Which of the following is NOT needed for DNA replication?

primer

helicase