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

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.

Phosphate and deoxyribose make up the side.

P

P

P

O

O

O

1

23

4

5

5

3

3

5

now it’s a nucleotide.

P

P

P

O

O

O

1

23

4

5

5

3

3

5

G C

Add a nitrogen base –

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

Sugar phosphate backbone (side)

Nitrogen base pairs

Nitrogen base

Here in the nucleus the DNA must remain

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

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

Ribosomes are the little dots.

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

nucleus

ribosomes

mRNA

DNA

Phosphate and just ribose make up the side.

P

P

P

O

O

O

1

23

4

5

5

3

3

5

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 –

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

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

nucleus

ribosomes

mRNA

DNA

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

Translation

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

Proteins are formed in the ribosomes when amino acids carried

by each tRNA combine!

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

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

ATTCGATCGGACT

Nitrogen base sequence

Genes form chromosomes

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

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

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

Original1 DNA

Replicas2 DNAs

For Adenine pairs with Thymine

And Cytosine pairs with Guanine

C A GT A

G T CA T

Unless its RNA

C A GU A

G T CA T

then Uracil replaces Thymine.

DNA

mRNA

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

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