DNA PROCESSES Transcription using DNA Vs. Replication of DNA.
DNA
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DNA The Structure of:
description
The Structure of:. DNA. Objectives:. By the end of the day, you should: Know what DNA stands for Understand the shape of DNA and be able to label all parts Know the pairs of nucleotides Know how DNA is used. What is DNA?. DNA is the molecule that carries genetic information - PowerPoint PPT Presentation
Transcript of DNA
DNAThe Structure of:
Objectives:
By the end of the day, you should: Know what DNA stands for Understand the shape of DNA and
be able to label all parts Know the pairs of nucleotides Know how DNA is used
What is DNA?
DNA is the molecule that carries genetic information
So what does that really mean?
“DNA”
DNA stands for deoxyribonucleic acid
We’ll come back to this one…
The Shape
The shape of the DNA molecule is called a double helix Think of DNA’s shape as a ladder that
has been twisted
Straight TwistedLadder Ladder
A Closer Look
It’s nice to think of DNA looking nice and simple
like this:
A Closer Look
But, it really looks more like this:
Let’s break it down…
The “Sides”
Each side of the ladder is called a sugar-phosphate backbone
this part
The “Sides”
The sugar-phosphate backbone…up close Consists of:▪ Phosphate group▪ Deoxyribose sugar
group
The “Rungs”
The rungs of the latter are made up of nitrogenous bases Bonded to the sugar group There are 4 different kinds of
bases in DNA…
The BasesPu
rine
sPy
rim
idin
es
Nucleotide
A deoxyribose sugar group and a phosphate group and a nitrogenous base make up a nucleotide
P
P
P
P
Adenine
Guanine
Cytosine
Thymine
Putting it Together The deoxyribose sugar group of one nucleotide
bonds to the phosphate group of another nucleotide to form the sugar-phosphate backbone
The nitrogenous bases of one sugar-phosphate backbone bond to the nitrogenous bases of the other sugar-phosphate backbone to make base pairs A only bonds with T G only bonds with C
Putting it Together
Quick Practice: If you had a strand of DNA where one
side had this sequence of bases: ATAGGCAT
What would the other side’s sequence be???
Putting it Together
PA
PA
P
G
PC
PC
P
G
P
T
P
T
Use?
Now that you know about the structure of DNA, let’s revisit its function…
Use?
Short version: DNA stores genetic information
Long version: The sequence (order) of bases on the strand of DNA is a code for a blueprint of hundreds of thousands of different proteins that, when made, make up living things
