Study Guide DNA Replication PDF

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study guide for DNA replication includes definitions, ques./answers, and a diagram...

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Study Guide: DNA Replication Terms: 1.

X-ray crystallography- Maurice Wilkins and Rosalind Franklin were using the technique called X-ray crystallography to study molecular structure

2.

Origin of replication- where replication begins at special sites/ where the two DNA strands are separated, opening up a replication “bubble”/ Prokaryotes have a single origin in their circular chromosome/ Eukaryotic chromosome may have hundreds or thousands of origins of replication

3.

Replication fork- At the end of each replication bubble (synthesis starts)/ a Y-shaped region where new DNA strands are elongating

4.

Helicase- Unwinds DNA helix

5.

RNA primer- is several complementary strands of RNA added to the lagging strand of DNA by RNA polymerase. It will begin synthesis of the lagging strand in DNA replication

6.

Primase- Adds RNA primer to start synthesis

7.

Topoisomerase- Relieves torsional strain caused by unwinding of DNA

8.

DNA polymerase- once a primer is added enzymes catalyze the elongation of new DNA at a replication fork

9.

Leading strand- one template strand of DNA, the DNA polymerase synthesizes a leading strand continuously, moving toward the replication fork

10.

Lagging strand- is one of two strands of DNA at a replication fork (the other strand is called the leading strand). A lagging strand requires a slight delay before it is replicated, and it must be replicated discontinuously in small fragments.

11.

Okazaki fragments- lagging strand is synthesized as a series of segments

12.

Mismatch repair- DNA, repair enzymes correct errors in base pairing

13.

Nucleotide excision repair- damaged stretches of DNA are cut out and repaired

14.

Telomeres- Eukaryotic chromosomal DNA molecules have repeated nucleotide sequences at their ends (human is TTAGGG)/ do not prevent the shortening of DNA molecules, but postpone the erosion of genes near the ends of DNA molecules/ connected to aging

Ques: 1.

What is the semiconservative model of DNA replication? 

The mode by which DNA replicates. Each strand acts as a template for a new double helix. The established model of DNA replication in which each double-stranded molecule is composed of one parental strand and one newly polymerized strand

2.

What was the conservative model of DNA replication? 

A hypothetic form of replication in which a double-stranded DNA (dsDNA) produces two daughter dsDNAs, one of which consists of the two original strands whereas the other daughter DNA consists of two newly synthesized chains.

3.

What was the dispersive model of DNA replication? 

A form of DNA replication in which the original DNA chain breaks and recombines in a random fashion before the double helix structure unwinds and separates to act as a template for messenger RNA synthesis. There is no evidence that it occurs in nature

Be Able to identify the elements found in the following diagram:...