Chapter 1111.2 From DNA to

Protein

• DNA can make RNA• RNA = Ribonucleic

Acid• RNA

–Single strand that helps build protein

Differences• DNA

– Double stranded– Sugar = Deoxyribose– 4 Nitrogen Bases

• Adenine• Guanine• Cytosine• Thymine

• RNA– Single stranded– Sugar = Ribose– 4 Nitrogen Bases

• Adenine• Guanine• Cytosine• URACIL (attaches to

adenine

3 Types of RNA

1. Messenger RNA (mRNA) – Brings information from the

DNA in the nucleus to the cell’s cytoplasm

3 Types of RNA• Ribosomal RNA (rRNA)

– Clamps onto mRNA to assemble amino acids in correct order

3 Types of RNA• Transfer RNA (tRNA)

– Transfers amino acids to ribosomes to be assembled into proteins

Types of RNA

Steps in Protein Synthesis1. DNA sends out code

2. mRNA carries code to ribosome

3. tRNA pick up amino acids

4. tRNA carries amino acid to ribosome

5. force together to make protein

Transcription• Results in the formation of one

single stranded RNA (Transcription DNA makes RNA)

Codon• Each set of three nitrogen bases

in mRNA representing an amino acid is known as a codon.

• Nitrogen base order in mRNA determines the type and order of amino acids in a protein. 64 possibilities