DNA Structure

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Slide 1

DNA

Structure

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DNA Structure

DNA consists of two molecules that are arranged into a ladder-like structure called a Double Helix.

A molecule of DNA is made up of millions of tiny subunits called Nucleotides.

Each nucleotide consists of:

Phosphate group

Pentose sugar

Nitrogenous base

Slide 3

Nucleotides

Phosphate

Pentose

Sugar

Nitrogenous

Base

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Nucleotides

The phosphate and sugar form the backbone of the DNA molecule, whereas the bases form the “rungs”.

There are four types of nitrogenous bases.

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Nucleotides

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Nucleotides

Each base will only bond with one other specific base.

Adenine (A)

Thymine (T)

Cytosine (C)

Guanine (G)

Form a base pair.

Form a base pair.

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DNA Structure

Because of this complementary base pairing, the order of the bases in one strand determines the order of the bases in the other strand.

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Slide 9

DNA Structure

To crack the genetic code found in DNA we need to look at the sequence of bases.

The bases are arranged in triplets called codons.

A G G - C T C - A A G - T C C - T A G

T C C - G A G - T T C - A G G - A T C

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DNA Structure

A gene is a section of DNA that codes for a protein.

Each unique gene has a unique sequence of bases.

This unique sequence of bases will code for the production of a unique protein.

It is these proteins and combination of proteins that give us a unique phenotype.

Slide 11

Protein

DNA

Gene

Trait

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Your Task

Draw a flow chart to show how to get from: