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Biology 1002B Lecture Notes - Lecture 14: Guanine, Deoxyribose, Dna Ligase

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20 Apr 2016

School

Western University

Department

Course

Professor

Beth Mac Dougall- Shackleton

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Document Summary

[lecture 7 genome replication summary] September 30, 2013: purine and pyrimidine base- pairing in dna/rna. Two of the bases (adenine and guanine) are purines and the other two (thymine and cytosine) are pyrimidines. Purines bond with pyrimidines (a and t, c and g). These relationships are chargaff"s rules. In rna, thymine is replaced with uracil. The base pairing remains the same (a with u) This is complementary base pairing. The deoxyribose sugars are linked by the breaking of phosphate groups. This means dna polymerase can only add molecules at the 3i end (on the hydroxyl group) Because of the anti- parallel nature of dna, the template strand is read in the 3i to 5i end. The other must be replicated in short strands called okazaki fragments away from the replication fork. Leading strand: the new strand of dna synthesized in the direction of unwinding.

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Related Questions

QUESTION 1. Compared to eukaryotic genomes, only prokaryotic genomes:

A. contain DNA organized by histones.

B. contain usually one, circular chromosome.

C. contain plasmid DNA.

D. have chromosomes contained in a nucleus.

QUESTION 2. Azathioprine is a drug that may be prescribed to transplant recipients to reduce the chance of tissue rejection reactions. In its active state, it acts as a purine analogue, inhibiting DNA biosynthesis. This means that 6-mercaptopurine will be inserted in place of a purine containing nucleotides during DNA replication. Given this drug's mode of action, you would expect it to be incorporated into DNA in place of:

A. nucleotides containing guanine or cytosine.

B. nucleotides containing adenine or thymine.

C nucleotides containing adenine or guanine.

D. nucleotides containing guanine nucleotide or uracil.

QUESTION 3. RNA is distinguished from DNA because only RNA:

A. typically exists as a single-stranded molecule.

B. has a 3' to 5' directionality.

C. is composed of nucleotides that contain the sugar deoxyribose.

D. is composed of nucleotides that contain the nitrogen bases T, C, G, and A.

QUESTION 4. How are RNA nucleotides different from DNA nucleotides? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

A. RNA nucleotides do not contain thymine.

B. RNA nucleotides use the sugar ribose, while DNA nucleotides do not.

C. RNA nucleotides lack phosphate.

D. RNA nucleotides incorporate pyrimidine nitrogen bases, while DNA nucleotides only incorporate purine nitrogen bases.

1. Unlike DNA, RNA contains

deoxyribose

a double strand

phosphates

uracil

Nucleic acid structure

2. In transcription, uracil will bond with:

thymine

cytosine

adenine

guanine

Transcription

3. The first team of scientist to document the structure of DNA was:

Franklin and Wilkins

Watson and Crick

Pauling and Chargoff

None of the above

DNA structure

4. Organelles that synthesize protein are:

lysosomes

ribosomes

endoplasmic reticulum

golgi bodies

5. Most of the time in a cell's life, it's DNA is in the form of:

Chromatin

Chromatids

Replicated chromosomes

Spindle fibers

6. Uracil is a nitrogen base that pairs with adenine. Using this information, one could conclude that uracil is a:

Purine

Pyrimidine

Neither a purine or pyrimidine

Not enough information

7. a nucleotide does not consist of a:

polymerase

5-carbon sugar

phosphate group

nitrogen base

8. The genetic code in DNA of an individual depends on the sequence (order) of:

nucleotides

purines only

phosphates

sugars

9. Before a cell divides, it must duplicate its DNA in a process known as:

translation

transformation

transcription

replication

10. The basic unit (building block) of a protein is a (an):

carbohydrate

amino acid

lipid

hydrogen bond

11. Unlike DNA, RNA contains:

deoxyribose

a double strand

phosphates

uracil

12. The structure of DNA was first documented in:

1945

1953

1956

1962

13. In DNA replication, the new molecules produced are:

of unequal length

both assembled in the same direction

built with purines as the backbone

assembled in opposite directions

DNA replication

14. The "backbone" of DNA is composed of:

ribose and phosphates

deoxyribose and phosphates

ribose and uracil

deoxyribose and thymine

DNA structure

15. RNA differs from DNA in which of the following ways?

RNA is single-stranded

RNA contains ribose

RNA does not contain thymine

All of the above

DNA structure

16. Which of the following is NOT required for the transcription process itself?

RNA polymerase

DNA

uracil-containing nucleotides

ribosomes

The term replication refers to DNA's abilityto

a. attack bacteriaphages

b. make copies of itself

c. respond to X-ray photography

d. twist into a helix

Meselson and Stahl performed thedensity-gradient centrifugation of DNA in a solution of calciumchloride.

a. found in bacteria but not viruses.

b. found in proteins but not nucleic acids.

c. found in nucleic acid but notproteins.

d. found in viruses but not bacteria.

e. needed for bacteriophages to attach tobacteria.

Chargaff's rule state that in DNA, the amount ofadenine equals

a. the amount of cytosine

b. the amount guanine

c. the amount of thymine

d. the amount of guanine and thymine

Each complete turn of the DNA helix is howlong?

Griffin did an experiment in which live Rbacteria was changed by dead S bacteria. Such a change is anexample of

a. translocation

b. transformation

c. transduction

d. fertilization

One of Chargaff's rules state

a. A + T = G + C

b. A + G = T + C

c. A = G, T = C

d. A = C, T = G

The diameter of the DNA ladder is always

Which of the following is a purine base?

b. malomine

d. All of the above

According to the base pairing rules, guaninebinds with

Which of the following is a pyrimidinebase?

d. None of the answers

Each nucleotide in a DNA molecule is constructedof

a. a phosphate group, a five carbon sugar, and anitrogen base

b. a phosphate group, a six carbon sugar,and a nitrogen base

c. a phosphate group, a five carbon sugar, and aoxygen base

d. a sulfur group, a five carbon sugar molecule,and a nitrogen base