Chapter 12: DNA

12-1 DNA Griffith (1928): In bacteria, disease-causing factor is a gene. Avery (1944): The molecule that stores and transmits hereditary info is DNA.

12-1 DNA Hershey-Chase (1952): Genetic material of virus is DNA not protein.

12-1 DNA Chargaff’s rule: A = T and G = C in ALL organisms Franklin (1952): Used X-rays to determine DNA shape is a helix

12-1 DNA Watson & Crick (1953): Shape of DNA is double helix, which means two strands wound around each other.

12-1 DNA Chargaff’s rule: A = T and G = C in ALL organisms Adenine bonds with Thymine Guanine bonds with Cytosine

Nucleotide Structure Pyrimidines (T,C) Purines (A,G)

Nucleotide Structure Draw this nucleotide! Adenine Guanine Cytosine Base Phosphate Adenine Guanine Cytosine Thymine Deoxyribose Sugar

12-2 Chromosomes Prokaryotes: one circular molecule Eukaryotes: many linear molecules

DNA cytoplasm single circular molecule 1/1000 of eukaryotic nucleus Prokaryotes Eukaryotes cytoplasm single circular molecule 1/1000 of eukaryotic nucleus multiple linear molecules chromo-somes same molecule contains genetic info

12-2 Chromosomes

Histones Nucleosomes Coil Supercoil Chromosome

Write the complementary sequence below to complete each DNA strand. DNA Sequences Write the complementary sequence below to complete each DNA strand. Strand 1: 5’-ATCCGATACTTG-3’ 3’-TAGGCTATGAAC-5’ Strand 2: 5’-GCAGGTATCACC-3’ 3’-CGTCCATAGTGG-5’ Strand 3: 5’-TTCAAGCTAGAT-3’

DNA Videos The Structure of DNA The Most Awesome Science Video of DNA Ever Made Cracking the Code of Life (Part 1)

The Chemical Structure of DNA DNA Videos The Chemical Structure of DNA Open University Part 1 Part 2 Part 3

14. Brain & skin cells? If the DNA in all cells is the same, how are there different types of cells? Cells have the ability to turn off most genes and use only the genes specific to their function.

15. “Blueprint of Life”? DNA is the set of instructions that tells cells how to build an organism. Just like a blueprint tells how to build a house!

Gattaca

Gattaca Questions Choose one question below and write a paragraph (4-6 sentences) in response. Would you rather live in Gattaca’s society or today’s? Why? Why do you think the real Jerome killed himself at the end? Whose life was harder: Vincent’s or Jerome’s? Why?

DNA Replication Replication: DNA is copied Occurs before mitosis and meiosis First, DNA strand unzips

DNA Replication New nucleotides are added to each side Semi-conservative: Each new DNA strand is half old and half new

DNA Replication Ex: ATCCGTAGGTCA ATC-CGT-AGG-TCA Codon: a group of 3 nucleotides Ex: ATCCGTAGGTCA is actually ATC-CGT-AGG-TCA

DNA Replication Re-write this sequence of DNA in codons. GCTAACTGTCCA

GCTAACTGTCCA GCT-AAC-TGT-CCA DNA Replication Re-write this sequence of DNA in codons. GCTAACTGTCCA GCT-AAC-TGT-CCA

DNA Polymerase: enzyme that adds nucleotides

Replication Videos DNA Replication The Most Awesome Science Video of DNA Ever Made

Replicate this! GTA-CCT-GAG CAT-GGA-CTC

Replicate this! GTA-CCT-GAG CAT-GGA-CTC

Replicate this! GTA-CCT-GAG CAT… GTA… CAT-GGA-CTC

Replicate this! GTA-CCT-GAG CAT-GGA-CTC

Replicate this! New strand is complementary to old strand.

Your turn… AAG-TGC-ACT TTC-ACG-TGA

Your turn… AAG-TGC-ACT TTC-ACG-TGA

DNA Replication

DNA Replication Prokaryotic DNA

DNA Replication Eukaryotic DNA

DNA Replication DNA polymerase: enzyme that replicates DNA

goes in both directions results in 2 identical strands DNA Replication Prokaryotes Eukaryotes cytoplasm begins at one point nucleus begins in 100s of places at once goes in both directions results in 2 identical strands uses DNA polymerase

DNA Structure

Do you remember DNA? The full name of DNA is _____________ ______.

Do you remember DNA? The full name of DNA is deoxyribonucleic acid.

Do you remember DNA? The structure of DNA is called a ______ ______. This means __________ _____________________

Do you remember DNA? The structure of DNA is called a double helix. This means it has two strands connected like a ladder that is twisted.

Do you remember DNA? The double helix was discovered by ________ & ________.

Do you remember DNA? The double helix was discovered by James Watson & Francis Crick.

Do you remember DNA? The Base Pair Rule was discovered by _______ __________.

Do you remember DNA? The Base Pair Rule was discovered by Erwin Chargaff.

Do you remember DNA? The enzyme that replicates a strand of DNA is called ______ ______________.

Do you remember DNA? The enzyme that replicates a strand of DNA is called DNA polymerase.

DNA – The Double Helix Deoxyribonucleic acid Gene: a segment of DNA that codes for a particular protein In the nucleus Mitochondria & chloroplasts James Watson & Francis Crick Double helix Alternating sugar and phosphate molecules

DNA – The Double Helix 4 types of nitrogenous bases (adenine, guanine, thymine, cytosine) Deoxyribose Ribose A bonds with T; G bonds with C Adenine & guanine Nucleotides At the ribosomes, in the cytoplasm