From Gene to Protein Part 1: Replication

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

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

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

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

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

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

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

DNA Replication Video