DNADNAThe Structure of DNA

What does the DNA of all these organisms have in common?

They all share a universal genetic code.

What was this substance called?

DNA

Oswald Avery

Avery’s team determined that genes are composed of DNA

Chromosome

Gene

DNA

very large linear molecules

very large linear molecules

examples: DNA and examples: DNA and RNARNA

examples: DNA and examples: DNA and RNARNA

contain C, H, N, O, Pcontain C, H, N, O, Pcontain C, H, N, O, Pcontain C, H, N, O, P

sugar

phosphate

nitrogen

base

nucleotide

store genetic store genetic information, help to information, help to

make proteinsmake proteins

store genetic store genetic information, help to information, help to

make proteinsmake proteinsmade up of made up of nucleotides nucleotides

containing a sugar, containing a sugar, phosphate and a N-phosphate and a N-

basebase

made up of made up of nucleotides nucleotides

containing a sugar, containing a sugar, phosphate and a N-phosphate and a N-

basebase DNA molecule

sugar

phosphate

nitrogen base

A NUCLEOTIDE

H

H2

H H

H3

HH H

H

H

O

O

O

C C

C

N

N

PO

O

O

C

C

C C

C

O

OO

C

C

1.

2.

3.

1.

2.

3.

1. Phosphate Group2. 5-Carbon Sugar

(Dexoyribose or Ribose)3. Nitrogen Base

1. Phosphate Group

2. 5-Carbon Sugar(Dexoyribose or Ribose)

3. Nitrogen Base

Nucleotides, too

What is located in the nucleus?

What type of organic compound is DNA?

What is the monomer of DNA?

NucleotidesThere are four nitrogen bases making up four different nucleotides.

Adenine

Guanine

Thymine

CytosinePyrimidines

PurinesA

C

G

T

N base

Chargaff’s Base Pair RulesAdenine always bonds with thymine.

Adenine (A) to Thymine (T)

Guanine always bonds with Cytosine.

Guanine (G) to Cytosine (C)

The lines between the bases represent hydrogen bonds

A

CG

T

C

G

A

A

T

G

Nucleotide

PS

N-b

Pairing DNA NucleotidesWhat is a nucleotide?

Rule

A to

C to

T

G

What is the base pairing rule?What would be the complementary nucleotide pairing?

3’End

3’End 5’End

5’End

DN

A D

OU

BL

E H

EL

IX

ladder shaped molecule

Purpose of DNA

Why do we have DNA?

DNA contains our genetic codes

For what does it code?

for proteins

What actually makes you look the way you do - DNA or Proteins?

TRY THIS!

Answer:

DNA left strand: ACTTAGGCGTCA

DNA right strand: TGAACCGCAGT

What is RNA?

RNA stands for RiboNucleic Acid

DNA must have a “helper” molecule.

RNA is a single stranded nucleic acid

made up of monomers called nucleotides

sugar

phosphate

nitrogen base

A

B

C

RNA Nucleotides

A - Sugar (ribose)

B - Phosphate

C - Nitrogen base

sugar

phosphate

nitrogen base

Name the parts of the nucleotide.

TRY THIS!

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