DNA Structure Notes
DNA (slide 2)
DNA is often called the blueprint of life.
In simple terms, DNA contains _______________________________________________within
the cell.
Why do we study DNA? (slide 3)
We study DNA for many reasons:
1)
2)
3)
Chromosomes and DNA (slide 4)
Our genes are on our ______________________________.
Chromosomes are made up of a chemical called _____________________.
The Shape of the Molecule (slide 5)
DNA is a very long polymer.
The basic shape is like a ___________________________________________________.
This is called a ___________________________________________________________.
The Double Helix Molecule (slide 6)
The DNA double helix has _______________________________________ twisted together.
One Strand of DNA (slide 7)
The backbone of the molecule is alternating _________________________________________.
The teeth are _____________________________________________________.
One Strand of DNA (slide 8)
One strand of DNA is a polymer of _________________________________________.
One strand of DNA has many _____________________________________________ .
Four nitrogenous bases (slide 9)
Cytosine Thymine Adenine Guanine Two Kinds of Bases in DNA (slide 10)
_____________________________________________________ are single ring bases.
_____________________________________________________are double ring bases.
_____________________________________________________ are pyrimidines(slide 11)
Thymine and cytosine each have one ring of carbon and nitrogen atoms.
_____________________________________________________ are purines(slide 12)
Adenine and guanine each have two rings of carbon and nitrogen atoms.
Two Stranded DNA (slide 13)
Remember, DNA has _________________________ that fit together something like a zipper.
The teeth are the nitrogenous bases but why do they stick together?
Hydrogen Bonds (slide 14)
The bases attract each other because of ___________________________________________.
Hydrogen bonds are _____________________ but there are millions and millions of them in a
single molecule of DNA.
The bonds between cytosine and guanine are shown here with dotted lines
Hydrogen Bonds, cont. (slide 15)
When making hydrogen bonds:
1)
2)
Chargraff’s Rule: (slide 16)
Adenine and Thymine always join together
A
T
Cytosine and Guanine always join together
C
G
DNA by the Numbers (slide 17)
Each cell has about __________________________________ of DNA.
The average human has _________________________________________.
The average human has enough DNA to go from the earth to the sun more than _________ times.
DNA has a diameter of only 0.000000002 m.