2009-2010 protein synthesis making proteins dna lesson 1

2009-2010

Protein Synthesis Making Proteins

DNALesson 1

Do Now

• BrainPop Video: DNA

Bodies are made up of cells All cells run on a set of instructions

spelled out in DNA

Bodies Cells DNA

How does DNA code for cells & bodies? how are cells and bodies made from the

instructions in DNA

DNA Cells Bodies

DNA has the information to build proteins genes

DNA Proteins Cells Bodies

proteinscells

bodiesDNA gets all the glory,Proteins do all the work

How do proteins do all the work

• Proteins– proteins run living organisms– enzymes

• control all chemical reactions in living organisms

– structure• all living organisms are built out of proteins

cytoplasm

nucleus

Cell organization

• DNA– DNA is in the nucleus

• genes = instructions for making proteins

– want to keep it there = protected• “locked in the vault”

Cell organization• Proteins

– chains of amino acids– made by a “protein factory” in cytoplasm– protein factory = ribosome

nucleus

cytoplasm

ribosome

aa

aa

aa

aa

aa

aa

aa

aaaa

aa

buildproteins

In class assignment

• Multiple Choice worksheet

Homework

• Vocab and DNA worksheets

PASSING ON DNALesson 2

Do Now

• BrainPop video: RNA

• Multiple choice worksheet

Passing on DNA information• Need to get DNA gene information

from nucleus to cytoplasm– need a copy of DNA– messenger RNA

nucleus

cytoplasm

ribosome

mRNA

buildproteins

aa

aa

aa

aa

aa

aa

aa

aaaa

aa

mRNA

From nucleus to cytoplasm

DNA

transcription

nucleus cytoplasm

translation

trait

aa

aa

aa

aa

aa

aa

aa

aaaa

aa

protein

DNA vs. RNA

DNA• deoxyribose sugar • nitrogen bases

– G, C, A, T– T : A– C : G

• double stranded

RNA• ribose sugar • nitrogen bases

– G, C, A, U– U : A– C : G

• single stranded

Transcription

• Making mRNA from DNA

• DNA strand is the template (pattern)– match bases

• U : A• G : C

• Enzyme– RNA polymerase

Matching bases of DNA & RNA

• Double stranded DNA unzips

A G GGGGGT T A C A C T T T T TC C C CA A

Matching bases of DNA & RNA

• Double stranded DNA unzips

A G GGGGGT T A C A C T T T T TC C C CA A

Matching bases of DNA & RNA

• Match RNA bases to DNA bases on one of the DNA strands

U

A G GGGGGT T A C A C T T T T TC C C CA A

U

UU

U

U

G

G

A

A

A C CRNA

polymerase

C

C

C

C

C

G

G

G

G

A

A

A

AA

Matching bases of DNA & RNA

• U instead of T is matched to A

TACGCACATTTACGTACGCGGDNA

AUGCGUGUAAAUGCAUGCGCCmRNAaa

aa

aa

aa

aa

aa

aa

aaaa

aa

U C CCCCCA A U G U G A A A A AG G G GU Uribosome

In class assignment

• Protein Synthesis1

Homework

• Protein Synthesis Practice 2

MRNA CODESLesson 3

Do Now

• RNA Vocab worksheet

How does mRNA code for proteins

• mRNA leaves nucleus

• mRNA goes to ribosomes in cytoplasm

• Proteins built from instructions on mRNA

aa aa aa aa aa aa aa aa

How?

mRNA

U C CCCCCA A U G U G A A A A AG G G GU U

How does mRNA code for proteins?

TACGCACATTTACGTACGCGGDNA

AUGCGUGUAAAUGCAUGCGCCmRNA

Met Arg Val Asn Ala Cys Alaprotein

?

How can you code for 20 amino acids withonly 4 DNA bases (A,U,G,C)?

ribosome

aa aa aa aa aa aa aa aa

AUGCGUGUAAAUGCAUGCGCCmRNA

mRNA codes for proteins in triplets

TACGCACATTTACGTACGCGGDNA

AUGCGUGUAAAUGCAUGCGCCmRNA

Met Arg Val Asn Ala Cys Alaprotein

?

Codon = block of 3 mRNA bases

ribosome

• For ALL life!– strongest support for a

common origin for all life

• Code has duplicates– several codons for

each amino acid– mutation insurance!

Start codon AUG methionine

Stop codons UGA, UAA, UAG

The mRNA code

How are the codons matched to amino acids?

TACGCACATTTACGTACGCGGDNA

AUGCGUGUAAAUGCAUGCGCCmRNA

anti-codon

codon

tRNAUAC

MetGCA

ArgCAU

Val Anti-codon = block of 3 tRNA bases

aminoacid

mRNA to protein = Translation

• The working instructions mRNA• The reader ribosome• The transporter transfer RNA (tRNA)

mRNAU C CCCCCA A U G U G A A A A AG G G GU U

aaaa

aa

tRNA

GGU

aa

tRNA

U A C

aa

tRNA

GA C

tRNA

aa

A GU

ribosome

aa

aa

aaaa

aa

aa

aa

mRNA

From gene to protein

DNA

transcription

nucleus cytoplasm

protein

translation

trait

U C CCCCCA A U G U G A A A A AG G G GU Uribosome

tRNA

aa

protein

aa

aa

aa

aa

aa

aa

aa

aaaa

aa

aa

transcription

cytoplasm

nucleus

translation

trait

From gene to protein

transcriptiontranscription

translationtranslation

proteinprotein

In class assignment

• Protein Synthesis 3

Homework

• Vocabulary worksheet

PROTEIN SYNTHESIS LABLesson 4

MUTATIONS AND GEL ELECTROPHORESIS

Lesson 5

Do Now

2009-2010

MutationsChanges to DNA

Mutations

• Changes to DNA are called mutations– change the DNA– changes the mRNA– may change protein– may change trait

DNA TACGCACATTTACGTACG

mRNA AUGCGUGUAAAUGCAUGC

aa aa aa aa aa aa aaprotein

trait

Point Mutations

• One base change– can change the meaning of the whole protein

THEFATCATANDTHEREDRATRAN

THEFATCARANDTHEREDRATRAN

THEFATCATENDTHEREDRATRAN

OR

Does this changethe sentence?

A LITTLE!

Frameshift Mutations

• Addition = add one or more bases

AUGCGUGUAUACGCAUGCGAGUGA

MetArgValTyrAlaCysGluStop

AUGCGUGUAUACGUCAUGCGAGUGA

MetArgValTyrValMetArgValA

Does this changethe protein?

A LOT!

Frameshift Mutations

• Deletion = lose one or more bases

AUGCGUGUAUACGCAUGCGAGUGA

MetArgValTyrAlaCysGluStop

AUGCGUGUAUACGAUGCGAGUGA

MetArgValTyrAspAlaSerGA

Does this changethe protein?

A LOT!

2006-2007

BiotechnologyGel Electrophoresis

Many uses of restriction enzymes…

• Now that we can cut DNA with restriction enzymes…– we can cut up DNA from different people…

or different organisms… and compare it

– why?• forensics• medical diagnostics• paternity• evolutionary relationships • and more…

Comparing cut up DNA

• How do we compare DNA fragments?– separate fragments by size

• How do we separate DNA fragments?– run it through a gelatin – gel electrophoresis

• How does a gel work?

Gel electrophoresis

• A method of separating DNA in a gelatin-like material using an electrical field– DNA is negatively charged– when it’s in an electrical field

it moves toward the positive side

+–

DNA

“swimming through Jello”

• DNA moves in an electrical field…– so how does that help you compare DNA

fragments?• size of DNA fragment affects how far it travels

– small pieces travel farther

– large pieces travel slower & lag behind

Gel electrophoresis

+–

DNA

“swimming through Jello”

Gel Electrophoresis

longer fragments

shorter fragments

powersource

completed gel

gel

DNA &restriction enzyme

wells

-

+

Running a gel

1 2

cut DNA with restriction enzymes

fragments of DNAseparate out based

on size

3

Stain DNA– ethidium bromide

binds to DNA

– fluoresces under UV light

Uses: Evolutionary relationships

• Comparing DNA samples from different organisms to measure evolutionary relationships

–

+

DNA

1 32 4 5 1 2 3 4 5

turtle snake rat squirrel fruitfly

Uses: Medical diagnostic

• Comparing normal allele to disease allele

chromosome with disease-causing

allele 2

chromosomewith normal

allele 1 –

+

allele 1allele 2

DNA

Example: test for Huntington’s disease

Uses: Forensics

• Comparing DNA sample from crime scene with suspects & victim

–

+

S1

DNA

S2 S3 V

suspects crime scene sample

DNA fingerprints

• Comparing blood samples on defendant’s clothing to determine if it belongs to victim– DNA fingerprinting

RFLP / electrophoresis use in forensics

• 1st case successfully using DNA evidence– 1987 rape case convicting Tommie Lee Andrews

“standard”

“standard”

“standard”

“standard”

semen sample from rapist

semen sample from rapist

blood sample from suspect

blood sample from suspect

How can you compare DNA from

blood & from semen?RBC?

Electrophoresis use in forensics

• Evidence from murder trial– Do you think suspect is guilty?

“standard”

blood sample 3 from crime scene

“standard”

blood sample 1 from crime scene

blood sample 2 from crime scene

blood sample from victim 2

blood sample from victim 1

blood sample from suspect OJ Simpson

N Brown

R Goldman

Uses: Paternity

• Who’s the father?

+

DNA

childMom F1 F2–

Homework

• Regents Review: Protein Synthesis

Biodiversity Lab

GENETIC ENGINEERINGLesson 6

Do Now

• T Chart

We have been manipulating DNA for generations!

• Artificial breeding– creating new breeds of animals & new crop

plants to improve our food

Animal breeding

Breeding food plants• “Descendants” of the wild mustard

– the “Cabbage family”

Breeding food plants

Evolution of modern corn (right) from ancestral teosinte (left).

TACGCACATTTACGTACGCGGATGCCGCGACTATGATCACATAGACATGCTGTCAGCTCTAGTAGACTAGCTGACTCGACTAGCATGATCGATCAGCTACATGCTAGCACACYCGTACATCGATCCTGACATCGACCTGCTCGTACATGCTACTAGCTACTGACTCATGATCCAGATCACTGAAACCCTAGATCGGGTACCTATTACAGTACGATCATCCGATCAGATCATGCTAGTACATCGATCGATACTGCTACTGATCTAGCTCAATCAAACTCTTTTTGCATCATGATACTAGACTAGCTGACTGATCATGACTCTGATCCCGTAGATCGGGTACCTATTACAGTACGATCATCCGATCAGATCATGCTAGTACATCGATCGATACTGCTACTGATCTAGCTCAATCAAACTCTTTTTGCATCATGATACTAGACTAGCTGACTGATCATGACTCTGATCCCGTAGATCGGGTACCTATTACAGTACGATCATCCGATCAGATCATGCTAGTACATCGATCGATACT

human genome3.2 billion bases

Can we mix genes from one creature to another?

YES!

Mixing genes for medicine…

• Allowing organisms to produce new proteins– bacteria producing human insulin– bacteria producing human growth hormone

How do we do mix genes?

• Genetic engineering– find gene– cut DNA in both organisms– paste gene from one creature into other

creature’s DNA– insert new chromosome into organism– organism copies new gene as if it were its own– organism reads gene as if it were its own– organism produces NEW protein:

Remember: we all use the same genetic code!

Cutting DNA• DNA “scissors”

– enzymes that cut DNA

– restriction enzymes• used by bacteria to cut up DNA of

attacking viruses

• EcoRI, HindIII, BamHI

– cut DNA at specific sites• enzymes look for specific base sequences

GTAACGAATTCACGCTTCATTGCTTAAGTGCGAAGTAACG|AATTCACGCTTCATTGCTTAA|GTGCGAA

Restriction enzymes

• Cut DNA at specific sites

GTAACG AATTCACGCTTCATTGCTTAA GTGCGAA

GTAACGAATTCACGCTTCATTGCTTAAGTGCGAA

restriction enzyme cut site

restriction enzyme cut site

Uses of genetic engineering

• Genetically modified organisms (GMO)– enabling plants to produce new proteins

• Protect crops from insects: BT corn – corn produces a bacterial toxin that kills corn borer

(caterpillar pest of corn)

• Extend growing season: fishberries – strawberries with an anti-freezing gene from flounder

• Improve quality of food: golden rice – rice producing vitamin A

improves nutritional value

Bacteria

• Bacteria are great! – one-celled organisms– reproduce by mitosis

• easy to grow, fast to grow– generation every ~20 minutes

Bacterial DNA

• Single circular chromosome– only one copy = haploid– no nucleus

• Other DNA = plasmids!

bacteriachromosome

plasmids

There’s more…

• Plasmids– small extra circles of DNA– carry extra genes that bacteria can use– can be swapped between bacteria

• bacterial sex!!• rapid evolution = antibiotic resistance

– can be picked up from environment

How can plasmids help us?

• A way to get genes into bacteria easily– insert new gene into plasmid– insert plasmid into bacteria = vector– bacteria now expresses new gene

• bacteria make new protein

+

transformedbacteriagene from

other organism

plasmid

cut DNA

recombinantplasmid

vector

glue DNA

Grow bacteria…make more

growbacteria

harvest (purify)protein

transformedbacteria

plasmid

gene fromother organism

+

recombinantplasmid

vector

Applications of biotechnology

Homework

• Genetics Review