Introduction: DNA REPLICATION

________ Chromosomes in the original cell

________ Chromosomes after DNA replication

Two cells; each with _______ Chromosomes

Why is DNA called a nucleic acid?

DNA Replicationmakes identical copesof the DNA in thenucleus

Mitosis: The division of the DNA in the nucleus

Cytokinesis: The division of the cytoplasm

Nucleotides:The Building Blocks of DNA

5 Carbon Sugar

_______ _____

DNA and RNA are Nucleic Acids. They are composed of nucleotides

Base

Bases• A = Adenine• T = Thymine• G = Guanine• C = Cytosine

Two nucleotides

Base Sugar Phosphate

The Bases

• Purines • Pyrimidines

GA

CT

____ Hydrogen Bonds

____ Hydrogen Bonds

____ Hydrogen Bonds

____ Hydrogen Bonds

GCTAATGCCGTA

GTAGCT

CATCGA

Original Strand

New Strand

NewStrand

• DNA Replication is Semi conservative. What does this mean?

Template Template

DNA Replication

GCTAATGCCGTA

GTAGCT

CATCGA

Original Strand

New Strand

NewStrand

• DNA Replication is Semiconservative. What does this mean?

Template Template

DNA Replication

CATCGA

GTAGCT

½ Old ½ New

The Enzyme ________________ is Required for DNA Replication

The Bases In Nucleic Acids: DNA and RNA

Only in _____

Only in _____

DNA Versus RNA

• DNA is _________ stranded

• The 5C sugar in DNA is ________________

• The 4 bases found in DNA are:

1. ____________2. ____________3. ____________4. ____________

• RNA is __________ stranded

• The 5C sugar in RNA is ________________

• The 4 bases found in RNA are:

1. ____________2. ____________3. ____________4. ____________

Protein Synthesis

• DNA RNA ProteinTranscriptionTranslation

Review: Proteins

• Proteins are composed of?

• The primary structure of a protein is its?

• The site of protein synthesis it the?

The RNA Dictionary

Sample Problem

DNA:

RNA:

Protein

TAC AAA CTA CCT ATA ACT ATA____ ____ ____ ____ ___ ____ ____

The templatecodes for theRNA strand

____ ____ ____ ____ ___ ____ ____

____ ____ ____ ____ ___ ____ ____

*Note: The DNA template is the strand that codes for the RNA

This strand does not code for RNA

RNAPolymerase

RNA Polymerase

Sample Problem

DNA:

RNA:

Protein

TAC AAA CTA CCT ATA ACT ATAATG TTT GAT GGA TAT TGA TAT

*The templateThe other half

AUG UUU GAU GGA UAU UGA UAU

Met Phe Asp Gly Tyr

*Note: The DNA template is the strand that codes for the RNA

RNA Polymerase

TACAAACCCAATTAACGAACGAAGGCCTGAATT

ATGTTTGGGTTAATTGCTTGCTTCCGGACTTAA

DNA Templatefor RNA Synthesis

ComplementaryDNA Strand

AUGUUUGGGUUAAUUGCUUGCUUCCGGACUUAA

Transcription

Remove Introns (Represented by bold bases)and splice Exons together before RNA leavesthe nucleus

Processed RNA withIntrons removed

Translation: Show the amino acid sequenceof the protein

Unprocessed RNA in the nucleus

Transfer RNA

G C U

Anticodon

Amino acid attachmentsite

C G ACodon on mRNA

Sample Problem

mRNA: AUG UUU GAU AAG CCA UAA

DNA:

• Finish the DNA the made the given RNA •Finish drawing the tRNA’s for the codons indicated with red arrows• Show the primary structure of the protein synthesized with the given mRNA

DNA Template

The other strand of the DNA moleculeTACATG

AAATTT

Sample Problem

mRNA: AUG UUU GAU AAG CCA UAA

DNA: TAC AAA CTA TTC GGT ATTATG TTT GAT AAG CCA TAA

Met Pro

U A C G G U

Met Phe Asp Lys Pro TheProtein

Sample Problem

mRNA: AUG UUU GAU AAG CCA UAA

DNA:

• Finish the DNA the made the given RNA •Finish drawing the tRNA’s for the codons indicated with red arrows• Show the primary structure of the protein synthesized with the given mRNA

DNA Template

The other strand of the DNA moleculeTACATG

AAA CTA TTC GGT ATTTTT GAG AAG GGA TAA

U A C G G U

MET PRO

Methionine – Phenylananine - Aspartic acid - Lysine - Proline

Mutations

• Carcinogens

• For mutations to be passed to your offspring they must occur in what types of cells?– Examples:______________________________

Somatic Cells Versus Germ-line Cells

• Carcinogens typically affect what types of cells?___________________

Sickle Cell Anemoa

Summary

• The genetic code is universal

• Mutations can be harmful

• Mutations are a source of genetic variability

• The genetic code is a triplet code. Three bases code for one amino acid

• Substances that cause mutations are called mutagenic agents. Many mutagenic agents are also carcinogenic.