h-> chapter 10 page 180 a-> chapter 12 page 286 if you unwrap all the dna you have in all your...
TRANSCRIPT
Deoxyribonucleic Acid (DNA)
Primary Function = to store and transmit the genetic information that tells cells which proteins to make and when to make them.
an ORGANIC compound made up of repeating
subunits called NUCLEOTIDES composed of TWO long chains
of nucleotides
3 PARTS:
1. Sugar Molecule – deoxyribose
2. Phosphate Group – phosphorous(P) and oxygen (O)
3. Nitrogen Base – adenine(A), cytosine(C), guanine(G), and thymine(T)
1. Adenine 2. Guanine
Purines have two
rings
And come in two types:
Nitrogen bases come in two types:
2. Thymine1. Cytosine
Pyrimidines
have ONE ring
And come in two types:
Nitrogen bases come in two types:
Complimentary Base Pairing
Describes the pairing behavior of the bases.
TWO rules:1. Cytosine
bonds with Guanine
2. Adenine bondswith Thymine
In 1953, JAMES WATSON & FRANCIS CRICK suggested a model for the structure of
DNA.
Two nucleotide strands wrap around each other to form a double spiral (spiral staircase)
The Double Helix
= The process of copying DNA.
Overall: Two nucleotide chains separate and serve as TEMPLATE for a new nucleotide chain.
1. Helicase enzymes untwist and unzip the DNA helix. (A replication fork is now formed.)
2. DNA primase enzyme adds a primer to each side of the open strand.
3. DNA polymerase adds the new nucleotides one at a time.
4. Lastly, DNA ligase enzyme “glues” nucleotides together on the lagging strand.