The Purpose of DNA• To make PROTEINS!• Proteins give us our traits (ex: one protein gives a

person blue eyes, another gives brown

Central Dogma of Molecular Biology DNA mRNA Protein

• How do we get from DNA to proteins?– Through RNA!– RNA—Ribonucleic Acid– Has Ribose sugar instead of Deoxyribose and is single-stranded instead of double stranded•mRNA—messenger RNA•tRNA—transfer RNA•rRNA—ribosomal RNA

Transcription

• DNA mRNA

DNA bases mRNA basesAdenine AdenineGuanine GuanineCytosine CytosineThymine Uracil

Write the Complimentary RNA Strand to the DNA strands below

• ATGCGGATACATCCGATCGATGCAAT

• TGACGGACACTTACAGATTCTGTGAG

• GAGCATTAGCAGGACTGCACGATATT

• GTAGTAGTAGTAGTAGTAGTAGTAGT

Transcription Review

• DNA mRNA

Translation

• mRNA Proteins

• mRNA travels to the Ribosomes, where it is translated into AMINO ACIDS

• mRNA is read in groups of 3-nucleotides called Codons– AUG = 1 codon– CAU = 1 codon

• Each codon codes for 1 amino acid, which is matched by a tRNA molecule.

• The tRNA translates the message from mRNA into a specific chain of amino acids

Codon Wheel of Amino Acids

• A chain of amino acids = 1 protein• The order of the amino acids determines the

type of protein created

Amino Acids• Essential Amino Acids—We

have to obtain from food– Isoleucine– Leucine– Lysine– Methionine– Phenylalanine– Threonine– Tryptophan– Valine

• Non-Essential Amino Acids—body produces– Alanine– Aspargine– Aspartic Acid– Cysteine– Glutamic Acid– Glutamine– Glycine– Proline– Serine– Tyrosine– Arginine– Histidine

Construct the amino acid chain from the following mRNA strands

• AUGCGGAUACAUCCGAUCGAUGCAAUCAUGCAU

• AUGCGGACACUUACAGAUUCUGUGAGUCUCAAC

Transcribe the following DNA sequence to mRNA, divide into triplet codons, then translate the sequence to Amino Acids.

TACGATGCCATGCTGAGCTTGACCGCATCTAGGACTATGCA

DNA Mutations

• Point Mutation– Substitution of a single base•AUG CUG GAA CGA CUG UGA•AUG CUG GAG CGA CUG UGA

• Frameshift Mutation– Insertion or deletion of a single base•AUG CUG GAA CGA CUG UGA•AUG CUG AAC GAC UGU GA

»OR•AUG CUG GUA ACG ACU GUG A