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

They all share a universal genetic code.

1. You and the person next to you are 99.9% similar in your DNA content

2. There is only a .1% difference which is due to a different sequence of your nucleotides

When it comes to DNA, it turns out there's not that much difference between mice and men.

Mice and humans each have about 30,000 genes, yet only 300 are unique to either organism. Both even have genes for a tail, even though it's not "switched on" in humans.

About 99 percent of genes in humans have counterparts in the mouse

What is located in the nucleus?

NucleusChromosome

DNA

Nucleic Acid

Nucleotide

DNA

Video

The_Importance_of_DNA.asx

Purpose of DNA

• Why do we have DNA?

-Tells the genetic information

http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter14/animations.html#

Hershey & Chase experiment

What is 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

Remember DNA…• Nucleotides make up

nucleic acid

• Are made up of monomers that repeat to form a polymer

• Double helix shape

• Store genetic information

• Help make proteins

sugar

phosphate

nitrogen base

Nucleotides• There are four nitrogen bases making up

four different nucleotides.

Adenine

Guanine

Thymine

CytosinePyrimidines

PurinesA

C

G

T

N base

Chargaff’s Base Pair Rules• Adenine always bonds with thymine. A = T

• Guanine always bonds with Cytosine. G C

A

CG

T

C

G

A

A

T

G

Nucleotide

PS

N-b

Pairing DNA Nucleotides• What 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

BLE

HE

LIX

ladder shaped molecule

http://www.hhmi.org/biointeractive/media/DNAi_paired_strands-lg.wmv

Dna strands

RESULTS OF REPLICATION

• Two molecules of DNA that are identical

• Each is – half old (original strand from parent) – and half new (strand synthesized by DNA

polymerase)

DNA replication

http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/dna-rna2.swf

http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter14/animations.html#

http://www.hhmi.org/biointeractive/dna/animations.html

• http://learn.genetics.utah.edu/content/labs/extraction/

• Virtual dna extraction

A

B

C

RNA Nucleotides

• A - Sugar (ribose)• B - Phosphate• C - Nitrogen base RNA is A = U

G = C

sugar

phosphate

nitrogen base

Name the parts of the nucleotide.

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 RNA?

• DNA must have a “helper” molecule.

• RNA stands for RiboNucleic Acid

• RNA is a single stranded

• nucleic acid made up of monomers called nucleotides

sugar

phosphate

nitrogen base

What is the function of RNA?

• Carries DNA’s message code

• Helps make protein

• Types of RNA– Messenger RNA (mRNA)– Transfer RNA (tRNA)– Ribosomal RNA (rRNA)

Phosphate Group

Nitrogen Base

Sugar

(ribose)

RNA

RNA Codes for Amino Acids

• The nitrogen bases in RNA code for amino acids.

• A triplet of nitrogen bases codes for one amino acid.

• The triplet is called a codon.

Cracking the Code of LifeNOVA chronicles the race to reach one of the greatest milestones in the history of science: decoding the human genome. Aired April 17, 2001 on PBS

http://www.pbs.org/wgbh/nova/body/

PROTEIN SYNTHESIS

Cells build proteins following instructions coded in genes (DNA).

• Consists of two parts, transcription and translation

TRANSCRIPTION

DNA is copied into a complementary strand of mRNA.

WHY?

• DNA cannot leave the nucleus. Proteins are made in the cytoplasm. mRNA serves as a “messenger” and carries the protein building instructions to the ribosomes in the cytoplasm.

LOCATION OF TRANSCRIPTION

Nucleus

HOW TRANSCRIPTION OCCURS

1. RNA polymerase untwists and unzips a section of DNA from a chromosome.

2. RNA polymerase pairs free RNA nucleotides to the exposed bases of one of the DNA strands following base pair rules.

• Uracil replaces thymine

• Only 1 strand of DNA serves as a template, the other “hangs out”

3. Newly synthesized mRNA separates from template DNA and DNA zips back up.

• http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/transcription.swf

RESULT OF TRANSCRIPTION

mRNA strand with instructions for building a protein that leaves the nucleus and goes to the cytoplasm.

TRANSCRIPTION EXAMPLE

• Transcribe the following DNA Sequence in mRNA

DNA TAC CGG ATC CTA GGA TCA mRNA AUG GCC UAG GAU CCU AGU

GENETIC CODEThe “language” that translates the sequence

of nitrogen bases in DNA (mRNA) into the amino acids of a protein.

• Codon = three nucleotides on DNA or mRNA

• One codon specifies one amino acid• Some codons are redundant (code for the

same amino acid)• The genetic code is universal to all

organisms

LOCATION OF TRANSLATION

ribosome (in the cytoplasm)

PROCESS OF TRANSLATION

1. mRNA binds to the ribosome.

2. Ribosome searches for start codon (AUG)

3. tRNA brings correct amino acid (methionine) to the ribosome. “Call on me”

• Each tRNA carries one type of amino acid. • The anticodon (three nitrogen bases on

tRNA) must complement codon for amino acid to be added to protein chain

4. ribosome reads next codon

5. tRNA’s continue lining up amino acids according to codons

6. peptide bonds link amino acids together

7. ribosome reaches STOP codon

• Amino acid chain is released

Codons• One codon codes for one amino acid.

• A sequence of amino acids is a protein.

EX: ACG = amino acid (threonine)

CGC = amino acid (arginine)

GGA = amino acid (glycine)

ACG

GGAGGC

CCA

AAC

CCG

GCCCGC

Threonine

Arginine

GlycineGlycine

Proline

Asparagine

Proline

Alanine

Amino Acid

protein

• What does the chain of amino acids represent?

Threonine

Arginine

Glycine

Glycine

Proline

Asparagine

ProlineAlanine

Polypeptide Chain – A Protein

RESULT OF TRANSLATION

A Protein

PROTEINS

Structural and functional components of organisms.

• Composed of amino acids

• order of nucleotides in DNA determines order of amino acids in a protein

• One gene codes for one protein

Overall process of protein synthesis

transcription translation

DNA RNA Protein

http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/translation.swf

translation

• http://www.stolaf.edu/people/giannini/flashanimat/cellstructures/endomembrane%20protein%20synthesis.swf

Translation of the Genetic Code -

Protein Synthesis

A U G G G C U U A A A G C A G U G C A C G U U

This is a molecule of messenger RNA.

It was made in the nucleus by transcription from a DNA molecule.

mRNA molecule

codon

A U G G G C U U A A A G C A G U G C A C G U U

A ribosome on the rough endoplasmic reticulum attaches to the mRNA

molecule.

ribosome

A U G G G C U U A A A G C A G U G C A C G U U

It brings an amino acid to the first three bases (codon) on the mRNA.

Amino acid

tRNA molecule

anticodon

U A C

A transfer RNA molecule arrives.

The three unpaired bases (anticodon) on the tRNA link up with the codon.

A U G G G C U U A A A G C A G U G C A C G U U

Another tRNA molecule comes into place, bringing a second amino acid.

U A C C C G

Its anticodon links up with the second codon on the mRNA.

A U G G G C U U A A A G C A G U G C A C G U U

A peptide bond forms between the two amino acids.

Peptide bond

C C G U A C

A U G G G C U U A A A G C A G U G C A C G U U

The first tRNA molecule releases its amino acid and moves off into the cytoplasm.

C C G U A C

A U G G G C U U A A A G C A G U G C A C G U U C C G

The ribosome moves along the mRNA to the next codon.

A U G G G C U U A A A G C A G U G C A C G U U

Another tRNA molecule brings the next amino acid into place.

C C G

A A U

A U G G G C U U A A A G C A G U G C A C G U U

A peptide bond joins the second and third amino acids to form a polypeptide chain.

C C G A A U

A U G G G C U U A A A G C A G U G C A C G U U

The polypeptide chain gets longer.

G U C

A C G

The process continues.

This continues until a termination (stop) codon is reached.

The polypeptide is then complete.

• Protein synthesis animations

• http://www.wisc-online.com/Objects/ViewObject.aspx?ID=AP1302

• Protein synthesis manipulation

• http://learn.genetics.utah.edu/content/begin/dna/transcribe/

• http://www.schooltube.com/video/d2d0cc18a01645f19168/DNA-Rap-Video

• Rap up the process!!!!!!!

http://faculty.ccbcmd.edu/courses/bio141/lecguide/unit3/eustruct/endomembanim.html

Shows protein synthesis in a cell using multiple organelles