Biology Chapter 12

Who confirmed that DNA bases had relationships amongst each other

Erwin Chargaff

Who made the first x-ray images of DNA?

Rosalind Franklin

Who came up with the semiconservative DNA structure?

Meselson and Stahl

Who proposed the first DNA structure model?

Waston and Crick

What is the DNA/nucleotide formula?

5c deoxoxyribose, a phosphate and base

Which nitrogenous bases are purines?

Adenine and Guanine

Which nitrogenous bases are pyrimidines?

Uracil, Guanine and Thymine

The nitrogenous base attaches to

The prime 1 carbon of the sugar

The phosphate attaches to

The 5 prime carbon

The 3 prime carbon of a sugar attaches to

The 5 prime phosphate

DNA synthesizes in which direction

the 5’ to 3’ direction

Is new DNA added to the 3’ direction?

Yes

Are new nitrogenous bases added to the 5’ end of DNA?

No

What do 2 strands of DNA form?

a double helix

What are the three types of DNA structures?

Conservative, semiconservative and dispersive

Which two structures are incorrect?

Conservative and Dispersive

Which DNA structure is correct?

Semiconservative

What is a polymer

chains of monomers, or smaller molecules

Is DNA a polymer?

Yes

Is protein a polymer?

Yes

Monomers combine to form

Polymers

Small molecules combine to make

polymers

Which DNA replication consists of 2 chains separating and acting as templates to form new complementary strands?

Semiconservative replication

Which DNA replication consists of 2 old strands remaining together and 2 newly synthesized strands making their own double helix?

Conservative Replication

Which DNA replication consists of parental and newly synthesized strands randomly mixing during?

Dispersive replicaton

What is the first step of DNA replication?

DNA Helicase unwinds DNA

What is the DNA Helicase made of?

a group of enzymes

What is the DNA helicase responsible for?

Unwinding DNA

The DNA Helicase moves directly along the

phosphodiester backbone

What energy does the DNA Helicase use when unwinding the DNA?

ATP

What is the second step of DNA Replication?

The nucleotides align based on complimentary rules

What are the nucleotides? (Letters)

A, G, C, T

What does the DNA Gyrase do?

Relaxes DNA ahead of replication

What is the alternative name of DNA Gyrase?

Topiosomerase

What does Topiosomerase do?

Relaxes DNA

What does DNA Polymerase do?

Adds nucleotides to the 3’ end of the new chain

New nucleotides are added to which end of the new chain

the 3’ end

What is the third step of DNA replication?

DNA Polymerase adds new nucleotides to the 3’ end

What kind of bonds are the template and newly created strand connected by

hydrogen bonds

DNA is always formed in which direction

the 5' to 3’ direction

Which strand serves as the replication template?

The parent strand

Which strand is continued discontinuously?

The lagging strand

Which strand is continued continuously?

The leading strand

Which strand does NOT consist of Okazaki Fragments?

The leading strand

Which strand consists of Okazaki Fragments?

The lagging strand

What are Okazaki fragments?

Short lengths of nucleotides produced by the lagging strand

What is DNA ligase?

The enzyme that links okazaki fragments together

Which enzyme links okazaki fragments together?

The DNA ligase

Which primer initiates DNA synthesis?

RNA Primer

What does RNA Primer initiate?

DNA synthesis

What does DNA Primase do?

Makes RNA polymerase

Why does DNA Primase need to make RNA Polymerase?

So that RNA Polymerase can turn DNA sequences into RNA sequences

(True or False:) RNA polymerase is a primase

True

RNA Polymerase creates what for synthesis to occur?

RNA Primer

What does Primer RNA do?

Initiates DNA synthesis