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DNA by C. Stephen Murray
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DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

Jan 03, 2016

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Page 1: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

DNA

by C. Stephen Murray

Page 2: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

All life stores its genetic code in a molecule called DNA.

Page 3: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

All life stores its genetic code in a molecule called DNA.

Page 4: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

Phosphate and deoxyribose make up the side.

P

P

P

O

O

O

1

23

4

5

5

3

3

5

Page 5: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

now it’s a nucleotide.

P

P

P

O

O

O

1

23

4

5

5

3

3

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G C

Add a nitrogen base –

Page 6: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

Many make a double helix, if you add another side.

Sugar phosphate backbone (side)

Nitrogen base pairs

Nitrogen base

Page 7: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

Here in the nucleus the DNA must remain

Page 8: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

Before it takes a ride it must transcribe to the messenger RNA.

Page 9: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

All life moves its genetic code to the ribosomes as mRNA.

Ribosomes are the little dots.

Page 10: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

All life moves its genetic code to the ribosomes as mRNA.

nucleus

ribosomes

mRNA

DNA

Page 11: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

Phosphate and just ribose make up the side.

P

P

P

O

O

O

1

23

4

5

5

3

3

5

Page 12: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

makes it a nucleotide.

P

P

P

O

O

O

1

23

4

5

5

3

3

5

G C

Of course a nitrogen base –

Page 13: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

But mRNA is not a ladder, for it has only 1 side.

Page 14: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

The mRNA goes to the ribosome where the proteins must be formed.

nucleus

ribosomes

mRNA

DNA

Page 15: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

But before they can be made it must translate to the transfer RNA.

Translation

Page 16: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

Proteins are formed in the ribosomes with the help of the tRNA.

Page 17: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

Proteins are formed in the ribosomes when amino acids carried

by each tRNA combine!

Page 18: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

So where is this genetic code that distinguishes you from me?

Page 19: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

It’s in the sequence of the nitrogen bases that together form our genes.

ATTCGATCGGACT

Nitrogen base sequence

Genes form chromosomes

Page 20: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

When it makes a mistake when it replicates this is when DNA can mutate.

Original – ATTCGATCGGACT

Mutation - ATTGATCGGACT

“C” was deleted

Original – ATTCGATCGGACT

Mutation - ATTCGATACGGACT

“A” was inserted

Page 21: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

But if it doesn’t pass to the offspring it doesn’t really matter at all.

DNA

Mutation to ribosomes

No problem

Mutation to egg or sperm

Passes to offspring

Page 22: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

When it replicates each nitrogen base always has to pair in a certain way.

Original1 DNA

Replicas2 DNAs

Page 23: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

For Adenine pairs with Thymine

And Cytosine pairs with Guanine

C A GT A

G T CA T

Page 24: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

Unless its RNA

C A GU A

G T CA T

then Uracil replaces Thymine.

DNA

mRNA

Page 25: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

All life stores its genetic code in a molecule called DNA.

Page 26: DNA by C. Stephen Murray. All life stores its genetic code in a molecule called DNA.

All life stores its genetic code in a molecule called DNA.