DNA RNA DNA Deoxyribo Nucleic Acid Made up

DNA/ RNA

DNA Deoxyribo. Nucleic Acid Made up of Nucleotides Contains deoxyribose sugar Contains the genetic (hereditary) code for all living organisms. • Provides a “blueprint” or directions for all cellular processes • • Nucleotide

DNA • DNA is found in the nucleus in Eukaryotic cells • DNA is found in Chromosomes • In order of decreasing size – Nucleus Chromosome Gene DNA

DNA • Discovered by Watson and Crick • They determined that DNA was in the form of a double helix (twisted ladder) • Sides of the ladder are made of sugar and phosphorous • Steps (rungs) made of nitrogenous base pairs

DNA base pairs • • Adenine Thymine Guanine Cytosine • What are the base pair rules?

DNA base pair rules • Adenine always attaches to Thymine • Guanine always attaches to Cytosine Example: • A-T and T-A • G-C and C-G

DNA base pair practice Fill in the correct base pair sequence for the following: AGGCTA- A-T G-C C-G T-A A-T

More Practice T T A C G T C A G T-A A-T C-G G-C T-A C-G A-T G-C

What would happen if the code was altered? Mutation: any change or alteration in the sequence of DNA (genetic material) Types: Deletion: one or more bases are removed(deleted) Example: AATCG AACG The T was deleted

More Mutations • Addition (aka Insertion): One or more bases are added • Example: AATTCGC AATTCCGC A “C” was added Substitution: A base is replaced with a new base AATTGCG AATGGCG The “T” was replaced with a “G”

RNA Ribo. Nucleic Acid Made of nucleotides Contains Ribose sugar Contains Uracil instead of Thymine • Is vital in making proteins • Is single stranded • •

RNA base pair rules • There is only one difference in pairing the bases • Adenine always pairs with Uracil • Thymine still pairs with Adenine • Guanine still pairs with Cytosine • Example: A-U T-A G-C or C-G

Protein Synthesis

RNA • Two types – m. RNA • messenger RNA • translates the DNA code into codons – t. RNA • Transfer RNA • lines up amino acids in order of codons • Both used in protein synthesis at the ribosome

Protein Synthesis • Protein Synthesis: The process of making proteins • Remember proteins are made from long chains of amino acids • The sequence(order) of the amino determines what type of protein is being made • This process will need: – DNA – RNA • m. RNA • t. RNA • Ribosome

Protein Synthesis Steps • DNA Replication: DNA will “unzip” and copy itself • It will then “unzip” again to make a single strand that can make a strand of RNA • Transcription: The process of making an RNA sequence based on the DNA sequence.

Transcription practice DNA A-T T-A G-C T-A A-T Unzipped DNA A T G G T A m. RNA (transcription) U A C C A U

More Practice DNA A A G T T C m. RNA A-U G-C T-A C-G

Protein Synthesis • Translation: The process by which m. RNA “translates” the genetic code into triple letter combinations that represent the key to figuring out the correct order of amino acids

Protein Synthesis • Codon: The triple letter combination of nitrogenous bases (DNA Template) (m. RNA) Codons AATTTAAAGCCGGAT UUAAAUUUCGGCCUA UUA AAU UUC GGC CUA Hint: to make codons, just break up the m. RNA code into three letters

Protein Synthesis • The codons will then be used to code for a particular Amino Acid • A chart will be used to determine the Amino acid • The first 3 letters are used to represent the Amino Acid • Always use m. RNA for chart

More Practice DNA A A G T T C m. RNA Codon Amino Acid U U UUC Phe C A Lys A AAG G

• Use this chart with your m. RNA codons to determine amino acids • Start from the center and work your way out • AAG Asp

• This chart can also be used to code for amino acids

Protein Synthesis • Once codons are determined m. RNA brings the information to the Ribosome. • It is there that the t. RNA will transfer or bring the correct amino acid into place.

Protein Synthesis • Transfer RNA (t. RNA) will bring the correct amino acid into place • t. RNA will match its code (anti-codon) to the m. RNA codon • This will provide the correct sequence needed to make a protein • Remember: the sequence of Amino Acids determines what protein is being made The anti codon AAG matches up to the codon UUC This combination will always bring Phe into place

STEP 1 DNA Replicates and m. RNA created in the Nucleus STEP 2 m. RNA leaves the nucleus bringing codon information to the ribosome Random single amino acids t. RNA STEP 3 t. RNA brings the correct amino acid in to place based on the m. RNA code

Protein synthesis • STEPS • DNA copies itself (replicates) • m. RNA matches up to DNA code following the rules of the base pairing (transcription) • m. RNA translates DNA code into codons (triple letters) brings it to the ribosome • t. RNA then “transfers” the amino acids into the correct order.

Protein Synthesis • (DNA) AATTTAAAGCCGGAT • (m. RNA) UUAAAUUUCGGCCUA Codons UUA AAU UUC GGC CUA t. RNA Amino Acids AAU UUA AAG CCG GAU Leu Asp Phe Pro Asp A

Mutations re-visited DNA code: AATGGCCCTAAT m. RNA (codons): UUA CCG GGA UUA Amino Acids: Leu Pro Gly Leu

Mutations re-visited • What happens if the DNA code on the previous slide has a substitution of a “G” at the first “T” DNA (with mutations): AAGCCGCCTAAT RNA: UUC GGA UUA Amino Acids: Phe Gly Leu One simple change makes a completely different protein!!!!!!