Warm-Up 1. You are a “meep” made of one cell and two strands of DNA, one from mom and one from dad. Explain how you, the little meep, acquires more DNA.

Warm-Up

1. You are a “meep” made of one cell and two strands of DNA, one from mom and one from dad. Explain how you, the little meep, acquires more DNA inside of all of your cells.

Its all in the DNA

Cornell page 49 and copy what is in red.

DNA Function (What does it do?)

• DNA is the genetic information passed down from parent to offspring that makes an organism what it is • Found in everyone of an organisms cellsYes, every living organism has DNA!

And its all made of the same stuff!

DNA Structure

5’

5’

3’

3’

• DNA made of two phosphate backbones connected by base pairs

• Strands are antiparallel (One goes from 5’ to 3’ and the other goes from 3’ to 5’

DNA Structure

• DNA exists in the shape of a doublehelix (spiral staircase or ladder)

• Connected by the base pairs Adenine and Thymine and Guanine and Cytosine

Yes, draw the DNA double helix!

DNA Structure

• Adenine pairs with Thymine (A – T)

• Guanine pairs with Cytosine (G – C)

ComplimentaryBase Pairing Rules

FACT:The DNA in your cells is some 3 billion base pairs long

Compare that to the DNA you made yesterday

Taking a closer look at DNAEach DNA molecule (nucleotide) is made up of a phosphate group,Sugar group and a base

phosphate

basesugar

Draw

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RNARNA

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RNA Differs from DNARNA Differs from DNA1.1. RNARNA has a sugar has a sugar riboseribose

DNADNA has a sugar has a sugar deoxyribosedeoxyribose

2.2. RNARNA contains the base contains the base uracil uracil (U)(U)

DNADNA has has thymine (T)thymine (T)

3.3. RNARNA molecule is molecule is single-single-strandedstranded

DNADNA is is double-strandeddouble-stranded

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Structure of RNAStructure of RNA

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. Three Types of RNAThree Types of RNA

Messenger RNA (mRNA)Messenger RNA (mRNA) carries genetic information carries genetic information to the ribosomesto the ribosomes

Ribosomal RNA (rRNA)Ribosomal RNA (rRNA), , along with protein, makes along with protein, makes up the up the ribosomesribosomes

Transfer RNA (tRNA)Transfer RNA (tRNA) transfers amino acids to the transfers amino acids to the ribosomes where proteins ribosomes where proteins are synthesizedare synthesized

Warm-Up

What 2 molecules make up the sides of the DNA molecule?

DNA is the instructions for building what molecule in our cells?

DNA ReplicationHow we make more of it.

Remember:Since everyone of our cells needs a copy of DNA, every time a cell undergoes mitosis, DNA needs to get copied for the new cell.

MitosisPlant Cell

orAnimal Cell DNA is copiedParent cell splits

into to daughter cells

DNA Replication

CTAG A CTT GA

5’3’

C T A GT AA CTG

5’ 3’

DNAHelicase

G

C

TA

A

TT

DNA Polymerase

1.DNA Helicase unwinds DNA

double helix

2.DNA Polymerase reads

DNA from 3’ to 5’

3. DNA polymerase adds complimentary base pairs to each strand

C T A T GDNA

Polymerase

Old StrandNew Strand

3’

New Strand

Old Strand

5’

DNA Replication

Review:1.DNA helicase

unzips the double helix

2.DNA polymerase adds

complimentary base pairs to split up strands from 5’ to 3’

CTAG A CTT GA

C T A GT AA CTG5’ 3’

5’3’

CTAG A CTT GA

5’3’

C T A GT AA CTG5’ 3’

Old Strand

Old Strand

New Strand

New Strand

Both new DNAs are identical and made of one of the original DNA strands and a new strand that the DNA polymerase made. This is called semi-conservative.