DNA Deoxyribonucleic Acid -Code -blueprint -hereditary material

I Can: Identify parts of a DNA Molecule Do Now: 1. How are DNA, genes and chromosomes related? DNA contains many genes that are wrapped with special proteins to make a chromosome 2

Key Vocabulary DNA – hereditary material that is passed from parent to offspring Gene – piece of DNA containing information for making a specific protein Chromosomes – DNA wrapped around special proteins that keep it together. Genome: complete set of genes in an organism These are some vocabulary words I would like for you to be familiar with. Hereditary: passed form parent to child Offspring: children

DNA Structure Double Helix – Two strands that look like a twisted ladder Made up of millions smaller parts called Nucleotides. Each nucleotide has: Phosphate group sugar base

Nucleotides Phosphate Base Sugar

Nucleotides Phosphate and sugar form the sides Bases form the “steps”. There are four types of bases: A, T, C, & G

Nucleotides A Adenine T Thymine C Cytosine G Guanine

Complementary Base Pairing Adenine (A) Thymine (T) Cytosine (C) Guanine (G) Form a base pair. Form a base pair.

Complementary Base Pairing The order of the bases in one strand determines the order of the bases in the other strand.

A C T G G A T C

I can: Explain how DNA copies itself Do Now: 1. The sides of a DNA molecule are made up of _________. 2. The steps of the DNA molecule are made up of ________. 3. The four bases in DNA are ________. 4. Write the sequence of bases for the second strand: A G G - C T C - A A G - T C C - T A G Sugar and phosphate group bases Adenine, Thymine, Cytosine, Guanine T C C - G A G – T T C - A G G – A T C

What is DNA Replication? Copying DNA in a cell before it divides How much DNA do we need to copy? bacteria: 3 million base pairs humans: 3 billion base pairs

Where does it happen?

Why does it happen? So daughter cells have a complete copy of the parent DNA ? ? ? ?

When does it happen? Remember Interphase in mitosis? S-phase or synthesis

How does DNA replicate? Semi-conservative: New DNA molecule has one old strand and one new strand

I can: Explain how DNA copies itself Do Now: In what phase of the cell cycle does DNA replicate? Where in the cell does DNA replicate? DNA replicates semi-conservatively. What does semi-conservative mean? HW: page 57 # 1-6 INTERPHASE NUCLEUS New DNA molecule has one old strand and one new strand.

Key Vocabulary Replication fork – site where DNA is separated and copied Enzymes – made by living things; proteins with a specific function (saliva) Helicase separates two strands of DNA DNA Polymerase adds new bases Sequence: order of bases – ATCGCAT These are some vocabulary words I would like for you to be familiar with. Hereditary: passed form parent to child Offspring: children

How does DNA replicate? 1. Replication Fork Site where DNA is separated and copied

The Enzymes Helicase: separates or “unzips” the two strands of the double helix

The Enzymes DNA polymerase: adds new bases and proofreads the bases

Video Clip http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120076/micro04.swf::DNA%20Replication%20Fork

Step 1: Helicase separates the two strands

Step 2: DNA Polymerase adds bases to copy each strand of DNA

Step 3: Two new DNA molecules are created

Write the complementary DNA strand for each of these DNA strands: GAATTACA CCAATTAG ATAGACAG DNA CTTAATGT GGTTAATC TATCTGTC

DNA Replication Review After replication, the new DNA molecule has one _______ strand and one ______ strand Sites where DNA separation & replication occur are called: __________ _______ DNA separates into two strands by the enzyme called __________. The enzyme ________________ adds bases along the original DNA strand. old new Replication fork Helicase Polymerase

I can: compare and contrast DNA and RNA DO NOW: What are the functions of Helicase and DNA polymerase? Helicase unwinds DNA DNA Polymerase adds new bases

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What are genes. Where are they located. What are ribosomes What are genes? Where are they located? What are ribosomes? Where are they located? Instructions for a protein Nucleus Make proteins cytoplasm Ribosome (Gene) DNA Protein RNA

Ribonucleic Acid (RNA )Structure Uracil (U) replaces Thymine (T) T pairs with A, but A pairs with U C pairs with G Single strand Messenger RNA (mRNA) carries the sequence for making a protein from the nucleus to the ribosome DNA: A G G - C T C - A A G - T C C - T A G mRNA: U C C - G A G - UU C - A G G - A U C

Quickdraw: How does DNA lead to a trait? RNA Protein Trait Stays in the nucleus Holds instructions for making proteins Used as body structures (muscle, bone, skin, hair), enzymes, hormones, etc. Made in the nucleus and goes to the cytoplasm Observable characteristic “Who you are”