1. From Gene to Protein
Part 1: Replication

2. What do genes code for? How does DNA code for an organism? DNA
proteins
cells
bodies

3. B D DNA structure P Made of nucleotides Sugar, phosphate, base
DNA sugar = deoxyribose
DeoxyriboNucleic Acid
4 nitrogenous bases
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
G & A = purines
T & C = pyrimidines B D P

4. DNA Structure continued
3’ (“three prime”) = sugar end D P
Double helix
“twisted ladder”
Sides = deoxyribose & phosphate
Connected with covalent bonds
STRONG!!!
Rungs = bases
A : T, C : G
Connected with hydrogen bonds
WEAK!!! G C D P D
covalent bond
hydrogen bond A P T
Antiparallel = sides run in opposite directions A T
5’ (“five prime”) = phosphate end

5. DNA gets all the glory, but proteins do all the work!
The “Central Dogma”
How do we move information from DNA to proteins?
transcription
translation
DNA
RNA
protein
trait
To get from the chemical language of DNA to the chemical language of proteins requires 2 major stages:
transcription and translation
DNA gets all the glory, but proteins do all the work!
replication

6. DNA replication
Strands “unzip” at the weak hydrogen bonds between bases
Enzyme called helicase
Helicase

7. DNA replication Enzyme DNA polymerase adds new complementary bases
DNA bases in nucleus
Enzyme DNA polymerase
adds new complementary bases
DNA
polymerase

8. Semi-conservative replication
Each strand is half “new” and half “old”
Semi-conservative replication
DNA
polymerase
New nucleotides
DNA
polymerase

9. DNA Replication Video