DNA Structure and Replication Review Test Multiple Choice

DNA Structure and Replication Review! Test Multiple Choice, Matching, Short Answer

What does DNA stand for? • Deoxyribo. Nucleic Acid

What is the sugar named in DNA? • DEOXYRIBOSE • 5 -Carbon sugar

In the DNA Double Helix, the sugar is bonded to what molecule? • Phosphate group

Follow up question – what is the bond that holds the sugar and phosphate together? !? • Covalent bonds

Phosphate and sugar are bonded together. What is then bonded to the sugar molecule? • Nitrogenous Base

Name the 4 nitrogenous bases. 1. Adenine 2. Guanine 3. Cytosine 4. Thymine

The nitrogenous bases are bonded together by what type of bond? This holds the 2 strands together. • Hydrogen bond

Tell me the difference. Purine Pyrimidine

Tell me the difference. Purine • Adenine • Guanine • 2 Ring Structure Pyrimidine • Thymine • Cytosine • 1 Ring Structure

What nitrogenous bases pair together? • Adenine – Thymine • Guanine – Cytosine • Purine – Pyrimidines!!

This scientist used X-ray diffraction to find information about DNA. Found that DNA is in the shape of a helix or a coiled spring. • Rosalind Franklin

DNA is in the shape of a double helix (twisted ladder). These Scientists realized that the double helix accounted for Franklin’s X-ray pattern, and it explained Chargaff’s rule of base pairing and how the 2 strands of DNA are held together. This 3 D model can even tell us how DNA can function as a carrier of genetic information • James Watson & Francis Crick

Define Chargaff’s Rule • the amounts of adenine and thymine are almost always equal, as are the amounts of guanine and cytosine.

Fill in the chart! Adenine Thymine Guanine Cytosine % of Each Base Pair 38%

Fill in the chart! Adenine Thymine Guanine Cytosine % of Each Base Pair 12% 38% Automatically you should know that Cytosine will be the same as Guanine. 38+38 = 76% 100 -76= 24 Adenine and Thymine = 24 Total 24/2 = 12% each

Tell me the general steps of DNA Replication

1 2 3 4 • DNA Unwinds and Unzips • Helix unwinds and 2 DNA strands separate at the Hydrogen bonds between nitrogen bases • DNA Polyermase helps to link free floating DNA nucleotides with complimentary nucleotides on each of the two strands • Covalent bonds join nucleotides above and below each other on the new strands. • Hydrogen bonds join complimentary base pairs • Each new DNA MOLECULE formed contains One parent strand a new strand

What ENZYME is present in the first step of DNA replication • DNA HELICASE! • HINT – THINK STRUCTURE – HELIX • (UNWIND & UNZIP)

What ENZYME is present to bring free nucleotides to the form the new strand of DNA. • DNA polymerase

What are the two strands referred to as in the process of Replication? • Parent Strand (original) • New Strand (copied)

What happens when an error is made in the replication process? • MUTATION

DONE! • Study o Note Packet o HW Packet o Feb Break Assignment