DNA Structure

What is DNA:

•DNA is a type of Nucleic Acid.•Nucleic acids are long chains of

__________________.nucleotides

What is DNA:

•Labeled drawing of a ______________:nucleotide

What is DNA:

•DNA = ______________________•DNA is found in the ____________ of the

cell. Its function is to _____________________

____________________.

Deoxyribonucleic acidnucleus

store and transmitgenetic information

Structure of DNA:

•Scientists _________________ and ________________ are credited with discovering the structure of DNA in _______.

James WatsonFrancis Crick

1953

Structure of DNA:

•However: _________________ played a role in helping them discover DNA’s structure. She used ________________________ to take pictures of DNA. Then she collaborated with Watson and Crick. Unfortunately she died at age _____ before any recognition was given to her.

Rosalind Franklin

x-ray crystallography

37

Structure of DNA:

•DNA is a molecule made of ____ strands which wind around each other in the shape of a ______________. The nitrogen bases point toward the ___________ of the molecule. In other words a molecule of DNA looks like a _____________________ with steps made of ________________.

2

double helixcenter

twisted laddernitrogen bases

Structure of DNA:

•The four different nitrogen bases in DNA are: ____________(A), _____________(G), ____________(C), _____________(T).Adenine GuanineCytosine Thymine

Structure of DNA:

•____ always pairs with ____, and •____ always pairs with ____.•The bases that pair with each other are

called _____________________.

A TC G

complimentary bases

Structure of DNA:

•Nitrogen Bases can be separated into two different categories:

Categories Purines Pyrimidines

Examples:

Drawing:

GuanineAdenine

Thymine

Cytosine

Structure of DNA:

•A single DNA molecule may contain ____________ of nucleotides (AKA: bases)

•The order of the nucleotides (bases) in a DNA is a code that provides instructions for making ____________. A segment of DNA that codes for a specific protein is called a ______.

thousands

proteingene

Structure of DNA:

•What is a gene: _______________________________________________.

A segment of DNA that codes for a specific protein

•What do proteins do?Make up all your traits – hair type and color (keratin), what color your skin is (melanin), what enzymes you have to break down food (lactase, peroxidase, amylase), how strong you are (actin/myosin)

Structure of DNA:

•Label the following:▫Base Pairs – Adenine, Guanine, Cytosine,

Thymine▫1 Nucleotide▫Backbone made of sugar