DNA Structure and Function. WHAT IS DNA? DNA stands for DeoxyriboNucleic Acid The main job of DNA is to make PROTEINS.

DNAStructure and Function

WHAT IS DNA?

DNA stands for DeoxyriboNucleic Acid

The main job of DNA is

to make PROTEINS

Function of DNA

DNA contains genes that codes for all of our traits It’s the blueprint to who you are todayPassed from cell to cell

Location of DNADNA is found in the nucleus of the cell for eukaryotes

DNA is found in the cytoplasm for prokaryotes (ex: bacteria)

Our genes are on our chromosomes.Chromosomes are made up of a chemical called DNA

Eukaryotes

DNA stays in nucleus of a cell to be

protected

Building Blocks of DNA

Each nucleotide consists ofDeoxyribose (sugar) Phosphate groupA nitrogen-containing base (A, G, T, C)

Nucleotide Structure

CH2

O

CC

C C

Sugar(deoxyribose)

NNitrogenous base (A, G, C, or T)

O=P-O O

Phosphate Group

Nitrogen Bases

Adenine (A)Guanine (G)Thymine (T)Cytosine (C)

A or G

T or C

Structure of DNA

Double Helix: Watson-Crick ModelStrands are held together by hydrogen bonds between bases

The sides are a sugar-phosphate backbone, while the “rungs” of the ladder are the nitrogen bases.

The DNA strands run in opposite directions

Base-Pairing Rules

Adenine (A) pairs with Thymine (T)Cytosine (C) pairs with Guanine (G)

DNA BASE-PAIRING PRACTICE

Make a copy of the following DNA Sequence:

DNA Strand #1: C G G T A

DNA Strand #2: G C C A T

DNA Strand #1: A T C G C G A A

DNA Strand #2: T

DNA BASE-PAIRING PRACTICE

Make a copy of the following DNA Sequence:

DNA Strand #1: C G G T A

DNA Strand #2: G C C A T

DNA Strand #1: A T C G C G A A

DNA Strand #2: T A

DNA BASE-PAIRING PRACTICE

Make a copy of the following DNA Sequence:

DNA Strand #1: C G G T A

DNA Strand #2: G C C A T

DNA Strand #1: A T C G C G A A

DNA Strand #2: T A G

DNA BASE-PAIRING PRACTICE

Make a copy of the following DNA Sequence:

DNA Strand #1: C G G T A

DNA Strand #2: G C C A T

DNA Strand #1: A T C G C G A A

DNA Strand #2: T A G C

DNA BASE-PAIRING PRACTICE

Make a copy of the following DNA Sequence:

DNA Strand #1: C G G T A

DNA Strand #2: G C C A T

DNA Strand #1: A T C G C G A A

DNA Strand #2: T A G C G

DNA BASE-PAIRING PRACTICE

Make a copy of the following DNA Sequence:

DNA Strand #1: C G G T A

DNA Strand #2: G C C A T

DNA Strand #1: A T C G C G A A

DNA Strand #2: T A G C G C

DNA BASE-PAIRING PRACTICE

Make a copy of the following DNA Sequence:

DNA Strand #1: C G G T A

DNA Strand #2: G C C A T

DNA Strand #1: A T C G C G A A

DNA Strand #2: T A G C G C T

DNA BASE-PAIRING PRACTICE

Make a copy of the following DNA Sequence:

DNA Strand #1: C G G T A

DNA Strand #2: G C C A T

DNA Strand #1: A T C G C G A A

DNA Strand #2: T A G C G C T T

Chargaff’s RuleA = T C = GA+T+C+G = 100

For example: The DNA is made up of 15% Adenine. Figure out the amount of the other nitrogen bases.

Adenine = Thymine Thymine = 15(a)G+C+15+15=100 (b)100-15-15=G+C (c)100-30 = 70G+C = 70 and Guanine =CytosineG= 35 and C=35Therefore: A=15%, T=15%, G=35%, C=35%

Practice ProblemThe DNA is made up of 30% Cytosine, calculate the amount of the other nitrogen bases.

Cytosine = Guanine G=3030+30+A+T=100 A+T= 100-30-30T+A=40A=20, T=20Therefore: G=30, C=30, A=20, T=20