Teacher Notes

This PPT was revised October 25, 2005.

This PPT introduces scientist/history of DNA, DNA structure and RNA structure.

There is a DNA Structure handout for this PPT. The DNA Scientists portion can be done using the book and review with this PPT.

DNADNAThe Structure of DNA

Should auld acquaintance be forgot,

And Auld Lang Syne!

Name the organelle and give its function.

And Auld Lang Syne!

Animal Plant

Nucleus

Ribosome

Endoplasmic Reticulum: aids in processing carbohydrates, lipids and proteins for export from the cell

Endoplasmic Reticulum

Golgi Body

Nucleus: control body of the cell; contains the genetic material (DNA)Golgi Aparatus: modifies, sorts, and packages materials from the ER for storage in the cell or secretion outside the cell

Ribosome: site where proteins are made

And Auld Lang Syne!

What is located in the nucleus?

What type of organic compound is DNA?

What is the monomer of DNA?

And Auld Lang Syne!What does the DNA of all these organisms have in common?

They all share a universal genetic code.

And Auld Lang Syne!

What is the name of these monomers?

To what organic compound group do they belong?

N

H

H

H

O

R

C C

O

H

N

H

H

H

O

R

C C

O

H

amine group

variable R group

carboxyl group

carboxyl groupamine group

And Auld Lang Syne!

What does the chain of amino acids represent?

Threonine

Arginine

Glycine

Glycine

Proline

Asparagine

ProlineAlanine

Polypeptide Chain – A Protein

History of Heredity

Why am I so gorgeous?

Gregor Mendel

Gregor Mendel determined that traits were passed from generation to generation.

But, I haven’tfigured out

how thishappens

Frederick Griffith

Griffith was working on a vaccine for Streptococcus pneumoniae

He worked with 2 strains of the bacteria:Smooth capsule that causes disease

Rough capsule that does not cause disease

Frederick Griffith

He added these bacteria strains, some dead and some living, to lab rats.

These are his results:

Frederick Griffith

Live R+ dead S

Bacteria

Live Smooth Bacteria

Live Rough Bacteria

Dead Smooth Bacteria

Griffith Proved:That somehow the dead bacteria have passed their disease-causing substance to the harmless, living bacteria.

Griffith discovered a factor that could transform harmless bacteria into disease-causing bacteria

What was this substance called?

DNA

Oswald Avery

Avery’s team determined that genes are composed of DNA

Erwin Chargaff

Chargoff discovered that DNA has the same amount of adenosine as thymine and the same amount of cytosine as guanine. A = T and G = C

A AA AA A

AT

T

T

T TT

T

CCC G G

G

Rosalind Franklin &Maurice Wilkins

Franklin and Wilkins used x-ray to discover that DNA was a double helix.

Watson and CrickWatson & Crick won a Nobel Prize for discovering the structural model of DNA.

They credited Wilkins and Franklin. Wilkins also got a Nobel Prize but Franklin did not. Rosalind had passed away and the Nobels are not awarded posthumously.

DNA is a Nucleic AcidWhat is a nucleic acid?

Nucleic acids are one of the major organic compounds.

Auld Lang Syne!Nucleic acids contain C, H, N, O, P

Are made up of nucleotide monomers

Store genetic information

Help make proteins

Examples: DNA & RNA

sugar

phosphate

nitrogen base

DeoxyriboNucleic Acid

DNA StructureFor what does DNA stand?What is the monomer for nucleic acids?

What is the structure of this monomer?phosphate

nucleotide

N base

PO4

SugarSugar

PO4

N baseThe numbers are the positions of the carbons on the sugar.

(the 3’ end)

5

4

3 2

1

(the 5’ end)

sugarnitrogen base

DeoxyriboNucleic Acid

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

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?

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.

Phosphate Group

Nitrogen Base

Sugar

(ribose)

RNA

Identify the parts of the RNA strand.

Rules for Base Pairing

Cytosine pairs with Guanine

Adenine pairs with Uracil

Notice that RNA has Uracil (not thymine)

A = U

C = G

Rules for Base Pairing

C = G

A = U

3’ DNA strand

5’ DNA strandRNA strand

C

A

T

G

G

U

C

A

What is the function of RNA?

Carries DNA’s message code

Helps make protein

Types of RNAMessenger RNA (mRNA)Transfer RNA (tRNA)Ribosomal RNA (rRNA)

DNA RNA

Sugar is deoxyribose

Sugar is ribose

Adenine base is present

Cytosine base is present

√

√

√ √

√ √

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

√

√ √

√

√

Comparing DNA & RNA

DNA RNA

Functions in protein synthesis

Composed of nucleotides

Template for synthesis of proteins

Transcribes the Template

More than one type

√ √

√ √

√

√

√

Comparing DNA & RNA

Works Cited