1. DNA structure p. 4 right side notebook 1
The illustration is a ‘model’ of the double helix forming part of a DNA molecule
(Slide 14)
p. 4 right side notebook

2. I can describe e the structure of DNA
Learning target
I can describe e the structure of DNA
Today I am…
Actively engaged in lecture of DNA.
So that I’ll be able to…
understand how important DNA is to life.
I’ll know I’ve got it when…
Complete all notes and homework.

3. DNA stands for deoxyribose nucleic acid2
DNA stands for deoxyribose nucleic acid
This chemical substance is present in the nucleus
of all cells in all living organisms
DNA controls all the chemical changes which
take place in cells
The kind of cell which is formed, (muscle, blood,
nerve etc) is controlled by DNA
The kind of organism which is produced (buttercup,
giraffe, herring, human etc) is controlled by DNA

4. DNA is a very large molecule made up of a long chain of sub-units
DNA molecule 3
DNA is a very large molecule made up of a long
chain of sub-units
The sub-units are called nucleotides
Each nucleotide is made up of
a sugar called deoxyribose
a phosphate group -PO4 and
an organic base

5. Ribose is a sugar, like glucose, but with only five
Ribose & deoxyribose 4
Ribose is a sugar, like glucose, but with only five
carbon atoms in its molecule
Deoxyribose is almost the same but lacks one
oxygen atom
Both molecules may be represented by the symbol

6. The most common organic bases are
The bases 5
The most common organic bases are
Adenine
(A)
Thymine
(T)
Cytosine
(C)
Guanine
(G)

7. Nucleotides are made up of a sugar, phosphate, and one of the bases.6
Nucleotides are made up of a sugar, phosphate, and one of the bases.
base
PO4
sugar
Phosphate group
It is the phosphate group which gives DNA its acidic properties
These 3 items combine to form a nucleotide

8. In fact, the DNA usually consists of a double
2-stranded DNA 9
PO4
PO4
PO4
PO4
In fact, the DNA usually consists of a double
strand of nucleotides
PO4
PO4
PO4
The sugar-phosphate chains are on the outside
and the strands are held together by chemical
bonds between the bases
PO4
PO4

9. Joined nucleotides 7
PO4
sugar-phosphate
backbone
+ bases
A molecule of DNA is formed by millions of nucleotides joined together in a long chain

10. The bases always pair up in the same way
Bonding 1 10
The bases always pair up in the same way
Adenine forms a bond with Thymine
Adenine
Thymine
and Cytosine bonds with Guanine
Cytosine
Guanine

11. The paired strands are coiled into a spiral called14
THE DOUBLE HELIX
bases
The paired strands are coiled into a spiral called
A DOUBLE HELIX
sugar-phosphate
chain

12. Structure of DNA Pages 220 - 223
Reading
Structure of DNA
Pages
Write down two facts from the reading that are not already in your notes. Bullet point the facts.

13. Show correct bonding of DNA bases
Requirements:
Using the code below: Draw the bases that bond together
G - A - C - T - T - G - C - T - A
Draw a nucleotide and label all three parts
Must have color
You can use the shapes from the notes or create you own shapes that fit together.

14. Short Video on DNA & RNA