Download Molecules to Eye Color - Springfield School District

Molecules to Eye Color
DNA, RNA and Protein
Synthesis
(Chapter 8) DNA
 Deoxyribonucleic
Acid
 Carries genetic information
 Found every cell
 Discovery
of DNA Structure:
http://www.youtube.com/watch?v=sf0YX
nAFBs8&safe=active
Structure
 Composed
of chains of nucleotides
 Nucleotides have 3 parts
 Phosphate
 Deoxyribose sugar
 Nitrogen base

4 kinds- G,C,T,A
 Chains
have a
“backbone” of
phosphates and
deoxyribose sugars
 Nitrogen bases sticking
out
Nitrogen Bases
DNA is double stranded





Another chain lines up
with the nitrogen bases of
the first
G pairs with C and T pairs
with A
The bases (and
strands)are held together
by hydrogen bonds
This forms a ladder shape
ladder is twisted forming a
double helix
DNA
DNA
“Unfolding DNA”
 Fold
a piece of notebook paper into four
columns
DNA Replication
 Makes
2 identical strands of DNA
 An enzyme called DNA polymerase
“unzips” the two strands by breaking the
H-bonds.
 Nucleotides with complimentary bases
are attached to the exposed strands

(If G is exposed, a C will be attached)
 This
results in 2 identical strands
RNA
 Brain
Pop!
 Ribonucleic acid
 Functions in turning DNA code into
proteins
 3 types



Messenger, mRNA
Transfer, tRNA
Ribosomal, rRNA
Structure
 Chains
of nucleotides
 3 main differences between DNA and
RNA
 1. Ribose sugar (not deoxyribose)
 2. Has U (uracil) instead of T (thymine)
 3. Single strand (not double)
Protein Synthesis
 Converting
 Proteins
DNA code into proteins
are composed of chains of amino
acids (AA)
Transcription
 mRNA
is created
from DNA
1. Section of DNA
(gene) unzips
2. RNA nucleotides are
paired with exposed
bases
Unfolding DNA to mRNA
 mRNA
strand leaves the nucleus
 DNA zips back up
 Codon-
3 base sequence of mRNA
 Anticodon- 3 base sequence on the tRNA
Translation
 mRNA
codons are matched with tRNA
anticodons.
 This places AA’s in a specific order.
 AA’s
bond together as tRNA release
 Creating a chain of AA’s with a specific
sequence
 Chains
of AA’s = protein