Download C - TeacherWeb

10/6
Opening Activity
CORE 3 AND 4: FIND YOUR NEW SEATS
What was Rosalind Franklin’s contribution to the
discovery of DNA?
How do you feel about her “recognition” in her
role of DNA?
1
3
DNA
• DNA, or
deoxyribonucleic
acid is often called
the blueprint of
life.
• In simple terms,
DNA contains the
instructions for
making proteins
within the cell.
4
Hair Color is Proteins
(or lack of proteins= blonde)
5
Watson & Crick’s Model
6
Why do we study DNA?
We study DNA for
many reasons,
e.g.,
• its central
importance to all
life on Earth,
• medical benefits
such as cures for
diseases,
• better food crops.
7
Chromosomes and DNA
• Our genes are on
our chromosomes.
• Chromosomes are
made up of a
chemical called
DNA.
8
The Shape of the Molecule
• DNA is a very long
polymer.
• The basic shape is
like a twisted ladder
or zipper.
• This is called a
double helix.
9
The Double Helix Molecule
• The DNA
double helix
has two
strands
twisted
together.
10
One Strand of DNA
• The backbone of
the molecule is
alternating
phosphates and
deoxyribose
sugar
• The teeth are
nitrogenous
bases.
phosphate
deoxyribose
bases
11
One Strand of DNA
nucleotide
• One strand of
DNA is a polymer
of nucleotides.
• One strand of
DNA has many
millions of
nucleotides.
12
Four nitrogenous bases
DNA has four different bases:
C
• Thymine T
• Adenine A
• Guanine G
• Cytosine
13
APPLE TREE
Adenine <-> Thymine
20
CAR GARAGE
Cytosine <-> Guanine
21
DNA Model
• DO NOT cut out anything yet.
• On the handout, use the key and color
the different parts of the DNA.
22
23
DNA by the Numbers
• Each cell has about 2
m of DNA.
• The average human has
75 trillion cells.
• The average human has
enough DNA to go from
the earth to the sun
more than 400 times.
The earth is 150 billion m
• DNA has a diameter of or 93 million miles from
the sun.
only 0.000000002 m.
24
25