Understanding DNA

Deoxyribonucleic Acid

Rosalind Franklin & Maurice Wilkins

James Watson & Francis Crick

Erwin Chargaff

A T

C G

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 proteins

made up of nucleotides made up of nucleotides containing a sugar, containing a sugar,

phosphate and a N-basephosphate and a N-base

made up of nucleotides made up of nucleotides containing a sugar, containing a sugar,

phosphate and a N-basephosphate and a N-base

Nucleotides

A. Sugar (deoxyribose)

B. Phosphate Group

C. Nitrogen Bases

A

B

C

Rules for Base Pairing:

B.     Adenine = Thymine

(A = T)

A.     Cytosine Guanine

(C G)

the lines between the letters are hydrogen bonds

* stores genetic information

What is the function of DNA?

C

G

A

A

T

G

Sugar

PhosphateNitrogen Bases

Fun Facts

If you wrote down all of the

bases in one cell, you would

fill a stack of 1,000 phone

books with A's, T's, G's and C's

Fun Facts

If you unraveled all your chromosomes from all of your cells and laid out the DNA end to end, the strands would stretch from the Earth to the Moon about 6,000 times.

Understanding RNA

Ribonucleic

Acid

Nucleotides

A. Sugar (ribose)

B. Phosphate Group

C. Nitrogen Bases

A

B

C

Rules for Base Pairing:

B.     Adenine = Uracil

(A = U)

A.     Cytosine Guanine

(C G)

Notice that RNA has Uracil (not thymine)

* helps to make protein

Types of RNA

A. Messenger (mRNA)

B. Transfer (tRNA)

C. Ribosomal (rRNA)

What is the function of RNA?

Phosphate Group

Nitrogen Base

Sugar

(ribose)

Comparing DNA & RNA

DNA RNA

Sugar is deoxyribose

Sugar is

ribose

Adenine base is present

Cytosine base is present

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√

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Comparing DNA & RNA

DNA RNA

Guanine base is present

Thymine base is present

Uracil base is present

Shape is double helix

√ √

√

√

√

Comparing DNA & RNA

DNA RNA

Shape is single stranded

Located in nucleus

Located in cytoplasm

Stores genetic information

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√ √

√

√

Comparing DNA & RNA

DNA RNA

Functions in protein synthesis

Composed of nucleotides

Template for synthesis of proteins

Transcribes the Template

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√ √

√

√

Comparing DNA & RNA

DNA RNA

More than one type

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