L2- DNA

What is DNA

The blueprint for life

What are both DNA and RNA

Polymers of nucleotides

Pyrimidines

Single ring bases

Purines

Double ring bases

What are examples of purines

• Adenine

• Guanine

Hydrogen bonds

Weak bonds but millions of them are held together between DNA nucleotides

How many Hydrogen bonds does C-G make

3

Examples of Pyrimidine

• Cytosine

• Thymine

• Uracil

Where does DNA replication begin

Orgin of replication

What do the two strands opening up form

Replication forks

Helicase

Unwinds and separates the 2 DNA strands by breaking the hydrogen bonds

Single stranded binding proteins

Attach and keep the 2 DNA strands seperated and untwisted

Primase

Lays down and synthesizes RNA primers

DNA polymerase 3

Synthesizes DNA

DNA polymerase 1

Replaces the RNA primer with DNA complementary to the template

DNA ligase

Joins broken pieces of DNA by catalyzing the formation of phosphodiester bonds

What is the sugar of RNA

Ribose

What is the sugar of DNA

Deoxyribose

What base replaces thymine in RNA

Uricil

mRNA

Copies a portion of unzipped DNA in the nucleus

rRNA

mRNA carries the message to the ribosome

tRNA

Attaches the proper amino acids at the ribosome

Transcription

• A portion of DNA unzips and mRNA composes a strand complementary to the DNA template

• mRNA then exits to the ribosome in the cytoplasm

Whhat is every three bases of mRNA called

CODON

Translation

Anticodon of tRNA attaches the proper amino acid to make a specific protein

What is the start codon

AUG or methionine