february 10, 2012 agenda opening bellwork discussion of dna video clip – get out a blank sheet of...

February 10, 2012

Agenda• Opening Bellwork• Discussion of DNA• Video Clip

– Get out a blank sheet of paper

• Structure of DNA – Lecture and Discussion

• Review Exams

Objectives• I will know the 4 bases and

how they pair up• I will know the basic

structure of the sugar-phosphate backbone.

CHAPTER 12:

DNA and RNA

Building block of DNA

• _____________ are the building block– Consist of:

• 5-Carbon sugar (Deoxyribose), • Phosphate group, and • Nitrogenous base:

– Adenine and Guanine : _____________– Thymine and Cytosine: _____________• Sugar and Phosphate groups form __________

while nitrogenous bases ______________ in between.

Nucleotides

backbonehydrogen bond

Purines (2 Rings)

Pyrimidines (Only one ring)

Purines Pyrimidines

Adenine Guanine Cytosine Thymine

Phosphate group Deoxyribose

Figure 12–5 DNA NucleotidesSection 12-1

Hydrogen bonds

Nucleotide

Sugar-phosphate backbone

Key

Adenine (A)

Thymine (T)

Cytosine (C)

Guanine (G)

Figure 12–7 Structure of DNASection 12-1

The Structure of DNA

= Phosphate = Deoxyribose (5-c sugar) = N-base

(A-T)(G-C)

Hydrogen bonds

February 14, 2012 <3

Agenda• Opening Bell Work

– Diagram DNA Structure

• Lecture and Discussion– Experiments that gave us

DNA

• Closing Bell Work– Most interesting experiment

• Homework:– 12.1 Outline – 2 Pages

Objectives• I will be able to summarize

each of the following peoples experiments and know why they were significant to our understanding of DNA:– Griffiths– Avery– Hershey and Chase– Franklin and Wilkins– Watson and Crick

Griffith and Transformation

• Griffith was trying to figure out how bacteria made people sick.– Specifically, Pneumonia

• 2 Pneumonia strains isolated from mice.– Smooth

• Did make people sick.

– Rough• Did NOT make people sick

Rough and smooth Bacteria

Griffiths

• Injected mice with – disease causing strain – died - X(– Non-disease causing strain - lived

• Thought it might be poison caused by bacteria.

• Took disease causing bacteria, heated them to kill the bacteria, then injected it into mice. – Lived

Griffiths Transformation• Mixed heat killed, disease causing bacteria with live

harmless ones– Injected it into mice– Neither should make mice sick, but what was the result?

• Mice got pneumonia and died• Dead, harmful bacteria had passed along ability to make

mice sick to the harmless bacteria• Known as TRANSFORMATION one strain of bacteria has

been changed into another. DNA had been transferred.

Disease-causing bacteria (smooth

colonies)

Harmless bacteria (rough colonies)

Heat-killed, disease-causing bacteria (smooth colonies)

Control(no growth)

Heat-killed, disease-causing bacteria (smooth colonies)

Harmless bacteria (rough colonies)

Dies of pneumonia Lives Lives Live, disease-causingbacteria (smooth colonies)

Dies of pneumonia

Section 12-1

Figure 12–2 Griffith’s Experiment

Transforming factor altered the Rough (harmless) Bacteria into Smooth (harmful) Bacteria

Avery, MacLeod and others• Did the same experiment as Griffith

– except with isolating the biological compounds • Carbohydrates, Lipids, Proteins and DNA

– See what was necessary for transformation

• Only DNA was necessary for the transformation to occur; therefore it is the transforming factor.

• Discovered DNA stores and transmits the genetic information from one generation to the next.

Hershey-Chase Experiments

• Alfred Hershey and Martha Chase (a girl!) studied viruses– A virus is a non living particle,

smaller than a cell, that can infect people.

• Bacteriophages are a type of virus that can infect bacteria. – Made of DNA or RNA and a

protein

Bacteriophages

• When a bacteriophage enters a bacteria, it injects genetic material.– Typically the genetic material is coding to make

more bacteriophages. – When the bacteria gets too full of bacteriophages,

it splits open and dies.• releasing TONS more bacteriophages

Hershey-Chase Experiments

• Hershey and Chase wanted to determine what part of the virus was the infecting agent– Protein coat or DNA/RNA

• Grew virus’ on a plate with radioactive isotopes. – Phosphorus – To Tag the DNA (proteins don’t have P)– Sulfur – To tag the protein (DNA doesn’t have S)

• If they found radioactive P or S in the bacteria cells, they would know what had been injected by the virus.

Hershey- Chase – RESULTS!

• Only found radioactive Phosphorus in the bacteria.

• What does that mean?– The genetic material of the virus was DNA, not

protein!

Hershey Chase Experiment

Bacteriophage with phosphorus-32 in DNA

Phage infectsbacterium

Radioactivity inside bacterium

Bacteriophage with sulfur-35 in protein coat

Phage infectsbacterium

No radioactivity inside bacterium

Section 12-1

Figure 12–4 Hershey-Chase Experiment

Validated that DNA is the agent of genes

Chargaff

• Noticed the % of Guanine and Cytosine were roughly equal

• Noticed the % of Adenine and Thymine were roughly equal

• No idea why, however

Percentage of Bases in Four Organisms

Source of DNA A T G CSource of DNA A T G C

Streptococcus 29.8 31.6 20.5 18.0

Yeast 31.3 32.9 18.7 17.1

Herring 27.8 27.5 22.2 22.6

Human 30.9 29.4 19.9 19.8

Streptococcus 29.8 31.6 20.5 18.0

Yeast 31.3 32.9 18.7 17.1

Herring 27.8 27.5 22.2 22.6

Human 30.9 29.4 19.9 19.8

Rosalind Franklin and Maurice Wilkins

• X-Ray Diffraction – Beams of high powered

X rays at concentrated samples of DNA to try and see structure.

– Received very little credit and died of cancer

Watson and Crick

• Watson and Crick were together trying to figure out the structure– By making cardboard and wire structures.

• Using Franklins X-Ray pictures, they were able to determine – DNA is a double helix (2 strands wound around

each other)– Base pairing explained Chargaffs Rules

Evidence of DNA Structure

• X-Ray Diffraction– Rosalind Franklin and

Maurice Wilkins• Chargaff base pairing

– A-– G-

• Watson and Crick Final DNA model– Double – Nobel Prize winners in

1962

TC

Helix

February 14, 2012


– Diagram DNA Structure

• Lecture and Discussion– Experiments that gave us

DNA

• Closing Bell Work– Most interesting experiment

• Homework:– 12.1 Outline – 2 Pages

Objectives• I will be able to summarize

each of the following peoples experiments and know why they were significant to our understanding of DNA:– Griffiths– Avery– Hershey and Chase– Franklin and Wilkins– Watson and Crick

February 15, 2012


– Summarize each of the experiments from yesterday

• Lecture and Discussion– 12.2 – DNA Replication– DNA Replication Drawing– Video Clip

• Closing Bell Work• Write a Paragraph describing the

DNA replication Process

• Homework– 12.2 Outline (2 Pages)

Objectives• I will be able to

– summarize and diagram the process of DNA replication

– know how and when it takes place

– what enzyme it uses to aid in the replication process

12-2: Chromosomes and DNA ReplicationA. DNA and Chromosomes

a. Prokaryotes ___________and their DNA is found in the cytoplasm.

b. It consists of a _____________________ DNA moleculec. This is the cells ______________d. Eukaryotic DNA is more complicatede. It is not free in the cytoplasm but is contained in the _________ of the cell.f. It forms a _______ of chromosomes not just oneg. humans have __, Drosophila have __ and a Sequoia tree have __.

lack nuclei

large, singular circular

chromosome

nucleusnumber

46 822

1. DNA Length

a. ______ molecules are surprisingly longb. prokaryotes DNA of E. coli is over __ million base pairs long.c. it must be ___________________ that is one-one thousandths it’s size. (see fig. 12-9)d. How does it do this?

DNA4

packed into a space

2. Chromosome Structure

a. DNA in _________________ is even more tightly packed.b. Eukaryotic DNA has over __________ DNA base pairs and is measured at over 1 meter of DNAc. It is folded into a tiny _____________d. How does it do this?e. Eukaryotic DNA contains both DNA and ___________(proteins) packed together to form ____________.

eukaryotic cells

6 billion

chromosome

histoneschromatin

2. Chromosome Structure (cont.)f. Chromatin consists of ______ tightly wrapped around histones to form a _________ structure called a ___________.

g. Nucleosomes pack with one another to form a thick fiber and are ____________ by a system of ________________.

h. During the _________ these fibers are dispersed and __________. i. During _________ they are condensed and coiled into the ________ chromosomes.j. What do nucleosomes do? _____________

_______________________________________ _______

DNAbeadlike

nucleosome

shortenedloops and coils

cell cyclenot visible

mitosisvisible

they are able to fold the DNA into the tiny space of the cell nucleus

DNA Supercoiling into Chromosomes

Chromosome

Supercoils

Coils

Nucleosome

Histones

DNA

double

helix

B. DNA ReplicationRemember what Watson and Crick learned about DNA:- Holds the in the sequence of nucleotides

- DNA Is - consists of two parallel strands of sugar-phosphate groups. Pairs of nitrogenous bases link the two strands together, forming a

- The Nitrogen (N)-base pairing isbecause each strand can be used to make the other strand.

Genetic code

double stranded

double helixcomplementary

B. DNA Replication- In ____________ replication begins on one point

on the chromosome and _________________________

- In ____________ the DNA replication occurs in ___________ of places and occurs in ____ _____________ until each chromosome is copied.

- The sites where separation and replication occur are called _______________.

prokaryotes continues in

two directions

eukaryoteshundreds bothdirections

replication forks

The Replication of DNA

Try your own:

A A T T T C G A T G G C (Strand 1) (Strand 2)

A.

This aids in DNA replication.

T T A A A G C T A C C G

Each strand of the double helix serves as a template, or model, for the new strand


B. Q: Why does DNA need to replicate?A:

C. DNA replication (aka: DNA synthesis) is done with the aid of .

When a cell divides to form new cells, the DNA must REPLICATE to ensure new cells have a new copy.

Enzymes (DNA Polymerase)


D. The Enzymes:1. 2.3.

4.

Separate or “unzip” the two strands of the double helix.

Insert the appropriate bases.

Covalently bond the sugar to the phosphate

Proofread the bases to make sure they were paired correctly

DNA Replication

Growth

Growth

Replication fork

DNA polymerase

New strand

Original strand DNA

polymerase

Nitrogenous bases

Replication fork

Original strand

New strand

The Replication of DNA (Summary)E. The steps in DNA replication

1.

2.

The Hydrogen Bonds (between N-bases) break and “unzips” the DNA

Each strand serves as a template for the attachment of complementary bases


Unzip Base Pairing 2 New Strands

February 15, 2012


– Summarize each of the experiments from yesterday

• Lecture and Discussion– 12.2 – DNA Replication– DNA Replication Drawing– Video Clip

• Closing Bell Work• Write a Paragraph describing the

DNA replication Process

• Homework– 12.2 Outline (2 Pages)


– summarize and diagram the process of DNA replication

– know how and when it takes place

– what enzyme it uses to aid in the replication process

February 16, 2012


– Diagram DNA replication

• Lecture and Discussion– 12.3a – RNA, Transcription– Drawing– Video Clip

• Closing Bell Work– Summarize Transcription Process

• Homework – 12.3a (Pgs. 300-303) Outline– ¾ Page

Objectives• I will know

– The difference between the types of RNA

– The definition of transcription and be able to summarize the process

– Be able to diagram what transcription would look like.

12-3 RNA and Protein Synthesis• DNA holds the genetic code to make •

• DNA• How does DNA get the code outside the nucleus?

A:

DNA mRNA Protein

proteinsProteins are made outside the nucleus on ribosomes

Cannot leave the nucleus

RNA(Ribonucleic Acid) acts as a messenger between DNA and the ribosomes and carries out the process by which proteins are made from Amino Acids.

Protein Synthesis overview

mRNA and DNA interaction

RNADNA

RNApolymerase

Adenine (DNA and RNA)Cystosine (DNA and RNA)Guanine(DNA and RNA)Thymine (DNA only)Uracil (RNA only)

I. The Structure of RNAA. Similar to DNA with a few differences:

DNA RNA

Strand

Sugar

Bases

Double Stranded

Deoxyribose

A-T G-C

Single Stranded (can form double strand if it folds back on itself).

Ribose

A-U G-C

The Structure of RNAB. 3 types of RNA:

1. mRNA (messenger RNA)

2. tRNA (transfer RNA)

3. rRNA (ribosomal RNA)

Copies the code off DNA in the nucleus and brings it out of the nucleus to the ribosomes

Carries amino acids to the ribosomes

Along with proteins, rRNA makes the subunits of the ribosomes

Different Forms of RNA

50S

30S

II. Transcription: RNA Synthesis

A. Transcription= The process by which a molecule of DNA is copied to a complementary strand of RNA

Page 147

Transcription: RNA Synthesis

B. Steps of Transcription: Step #1:

Step #2: RNA nucleotides base pair with complementary

DNA nucleotides

DNA

mRNA

RNA polymerase (enzyme) attaches to a sequence of DNA known as the Promotor and separates the 2 strands

A T C G

A CGU

with the help of RNA polymerase


Now try your own:

DNA= T T T A G A G A C C G T A T C

mRNA=

**Remember, RNA does not have Thymine!

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


Step #3:

Step #4:

RNA polymerase terminates (ends) transcription when it reaches the “STOP” site on the DNA

The final RNA strand leaves the nucleus through the pores in the nuclear envelope

• proteins are responsible for:– –

–

• DNA and RNA control the process of

• DNA RNA Protein

Controlling biochemical pathways(enzymes)

Synthesis of lipids, carbohydrates, and nucleotides

Cell structure and cell movement

making proteins

Transcription TranslationProtein Synthesis

Central Dogma

I. THE NATURE OF THE GENETIC CODE

A. Review:1. Proteins are ________________ 2. Proteins are made of monomers

known as _________________3. There are ___________ different

kinds of amino acids4. Amino acids form ______________ bonds5. A string of amino acids is known as

a _______________

polymers

amino acids

20

peptide

polypeptide

The Nature of the Genetic Code

B. DNA contains

C. The code is copied onto

D. Every

E. Each

the code to make proteins

mRNA in transcription

3 nitrogenous bases on the mRNA makes a codon.

codon specifies an amino acid that is to be placed in the polypeptide chain

** the chart on page 303 lists the 64 codons for the amino acids

Start and Stop Codons

The Nature of the Genetic Code

Example: DNA: T A C C A G C T C A C T

mRNA:Amino Acid:

F.

A AAU UU GG GGG C

Methionine

“Start” Codon

Valine Glutamic Acid

“Stop” Codon

An amino acid can have more than one codon

Example: Glycine GGG, GGA, GGU, GGC

The Genetic Code (p. 303)

February 16, 2012


– Diagram DNA replication

• Lecture and Discussion– 12.3a – RNA, Transcription– Drawing– Video Clip

• Closing Bell Work– Summarize Transcription Process

• Homework – 12.3a (Pgs. 300-303) Outline– ¾ Page


– The difference between the types of RNA

– The definition of transcription and be able to summarize the process

– Be able to diagram what transcription would look like.

February 17, 2012


– Diagram Transcription

• Lecture and Discussion– 12.3B - Translation

• Quiz• Homework

– 12.3b (Pages 303-306)– ¾ Page


– The difference between transcription and translation.

– The definition of translation and be able to summarize the process.

II. TRANSLATION

A. Translation=

B. The_______________ language is ___________________ into ________________ language

The decoding of a mRNA into a polypeptide (protein)

nucleic acid

translated

protein

TranslationKEY PLAYERS

Ribosomal RNA

ANTICODON

Translation Steps of Translation:

Step #1: After leaving the nucleus,

Step #2: In the cytoplasm,

Step #3: First

mRNA binds to the ribosome where rRNA is found

tRNA picks up amino acids and carries them to the mRNA

the anticodon on tRNA attaches to the mRNA codon that it matches.

If the mRNA is AUG what will the anticodon be?

Step #4: Then

Step #5: As each

Step #6: Finally, when

tRNA continues to match its ANTICODONS with corresponding mRNA CODONS

anticodon and codon bind together, a peptide bond forms between the 2 amino acids

The ribosome reaches the stop codon on the mRNA the new polypeptide is released

Translation

Translation part 2

http://library.thinkquest.org/C0123260/basic%20knowledge/images/basic%20knowledge/RNA/translation%20steps.jpg

February 17, 2012


– Diagram Transcription

• Lecture and Discussion– 12.3B - Translation

• Quiz• Homework

– 12.3b (Pages 303-306)– ¾ Page




February 21, 2012

Agenda• Quiz Review • Lecture and Discussion

– 12.3B – Translation– Diagram Translation– Video Clip

• Transcription/ Translation Worksheet

• Closing Bell Work– Summarize Translation

• Homework– 12.4 Outline ¾ Page Minimum




– Diagram the process of translation.

– How to take a DNA codon and transcribe it to RNA and translate it to proteins

February 22, 2012


– Diagram whole process from DNA to Proteins

• Lecture and Discussion– Diagram together– 12.4 – Mutations!

• Closing Bell Work• Homework

– Review Sheet


– Diagram the entire process a molecule would take from DNA mRNA Protein

– Define different types of Mutations

12-4 MutationsMutations in Genes =

A. Point Mutations = change involving a single nucleotide

Mutations that occur in individual genes. Can be changes in several or just one nucleotide

TYPE DEFINITION EXAMPLE

One base is replaced by another base

AGTGGATC

TCACCGAG

Nucleotide is removed AGTGGATC

AGTG|ATC

Nucleotide is added AGGTGGAT|C

AGGTGGATTC

Base substitution

Deletion

Insertion

Substitution InsertionDeletion

Gene Mutations:Substitution, Insertion, and Deletion

B. ___________________ = codon groupings are shifted after deletion or insertion.

Frameshift Mutations

Chromosomal Mutations:Involve the movement of large sections of

chromosome

Deletion

Duplication

Inversion

Translocation

DNA:ACA ATA TAG CTT TTG ACG GGG AAC CCC ATT

Transcribed into mRNA:UGU UAU AUC GAA AAC UGC CCC UUG GGG UAA

Translated into Amino Acid Sequence: Cysteine-Tyrosine-Isoleucine-Glutamic Acid-Asparagine- Cysteine-Proline- Leucine-Glycine

February 22, 2012


– Diagram whole process from DNA to Proteins

• Lecture and Discussion– Diagram together– 12.4 – Mutations!

• Closing Bell Work• Homework

– Review Sheet


– Diagram the entire process a molecule would take from DNA mRNA Protein

– Define different types of Mutations

february 10, 2012 agenda opening bellwork discussion of dna video clip – get out a blank sheet of...

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