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DNA-The code of life. Why don’t we all look alike?. CODON. 3 LETTER GROUPING OF NITROGEN BASE PAIRS AGC ATT. WARM-UP #7. Why do we Study DNA?. Disease Better vegetable, fruit, and animals. Crime History of life. DNA Facts. One chromosome has 50 - 250 million base pairs.

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Dna the code of life
DNA-The code of life

Why don’t we all look alike?


Codon
CODON

  • 3 LETTER GROUPING OF NITROGEN BASE PAIRS

  • AGC

  • ATT



Why do we Study DNA?

  • Disease

  • Better vegetable, fruit, and animals.

  • Crime

  • History of life


DNA Facts

  • One chromosome has 50 - 250

    million base pairs.

  • DNA is found in the mitochondria.

  • mDNA is only found in the egg. Sperm

    has no mitochondria so mDNA is passed

    to offspring from the mother.

  • One sequence of DNA is a genome or

    gene.

  • Unwind all our DNA, it will stretch from the moon

    and back 6000X.




Genetic material of cells
Genetic material of cells… your traits.

  • GENES – units of genetic material that CODES FOR A SPECIFIC TRAIT

  • Called NUCLEIC ACIDS

  • DNA is made up of repeating monomers called NUCLEOTIDES


Dna deoxyribonucleic acid

DNA your traits.(Deoxyribonucleic Acid)


A history of dna
A HISTORY OF DNA your traits.

  • Discovery of the DNA double helix

    A. Frederick Griffith – Discovers that a factor in diseased bacteria can transform harmless bacteria into deadly bacteria (1928)

    B. Rosalind Franklin- X-ray photo of DNA.

    (1952)

    C. Watson and Crick- described the DNA molecule from Franklin’s X-ray.

    (1953)


Discovery of DNA your traits.

Invented X-ray diffraction photography. Photo used to determine the shape of DNA is spiral.

Rosalind Franklin -


DISCOVERY OF DNA your traits.

James Watson and Francis Crick used the information from Franklin and other scientists to build a 3-D model of DNA.

Won the Nobel Piece Prize in Chemistry in 1961.


Watson crick proposed
Watson & Crick proposed… your traits.

  • DNA had specific pairing between the nitrogen bases:

  • ADENINE – THYMINE

  • CYTOSINE - GUANINE

  • DNA was made of 2 long stands of nucleotides arranged in a specific way called the “Complementary Rule”


DNA your traits.

DNA stands for –

Deoxyribonucleic acid

Functions of DNA:

1. Carries the codes to make proteins.

  • Pass on genes/traits from parent to child


STRUCTURE OF DNA your traits.

These three parts form the basic unit of DNA called the NUCLEOTIDE.

phosphate

Nitrogen base

Can be A, T, C or G

Sugar

(deoxyribose)


STRUCTURE OF DNA your traits.

Side Pieces(The Rope Part)

Are alternating units of a 5 carbon sugar and a phosphate group. These go down both sides of the molecule

phosphate

Sugar (called deoxyribose)


STRUCTURE OF DNA your traits.

Nitrogen Bases (Steps of the ladder) -

  • Adenine - A

  • Thymine – T

  • Cytocine – C

  • Guanine - G

The bases are connected to the sugar only !!!!!


Dna nucleotide

Phosphate your traits.

Group

O

O=P-O

O

5

CH2

O

N

Nitrogenous base

(A, G, C, or T)

C1

C4

Sugar

(deoxyribose)

C3

C2

DNA Nucleotide


phosphate your traits.

adenine

sugar

thymine

cytocine

guanine


How are the nucleotides held together
How are the nucleotides held together? your traits.

  • Nucleotides are held together by covalent bonds between the sugar of one nucleotide and the phosphate of the next.


DNA your traits.


Dna double helix

“Rungs of ladder” your traits.

Nitrogenous

Base (A,T,G or C)

“Legs of ladder”

Phosphate &

Sugar Backbone

DNA Double Helix


Nitrogenous bases

A or G your traits.

T or C

Nitrogenous Bases

  • A + T = 2 bonds; C + G = 3 bonds

  • PURINES

    1. Adenine (A)

    2. Guanine (G)

  • PYRIMIDINES

    3. Thymine (T) URACIL for RNA

    4. Cytosine (C)


Base pairings

H-bonds your traits.

G

C

A

T

BASE-PAIRINGS

2 Bonds

3 bonds


STRUCTURE OF DNA your traits.

One complete turn of the double helix is 10 base pairs or 10 steps on the ladder


Dna double helix1

5 your traits.

O

3

3

O

P

P

5

5

C

O

G

1

3

2

4

4

2

1

3

5

O

P

P

T

A

3

5

O

O

5

P

P

3

DNA Double Helix


Chargaff s rule

C your traits.

T

A

G

Chargaff’s Rule

  • Adeninemust pair with Thymine

  • Guanine must pair with Cytosine

  • Their amounts in a given DNA molecule will be about the same.


Chargaff s rule1
Chargaff’s Rule your traits.

  • Chargaff discovered that the percentage of A and T were equal. The same for C and G. This observation became Chargaff’s rule. This is always the same no matter what organisms.


Genetic diversity
Genetic Diversity… your traits.

  • Different arrangements of NUCLEOTIDES in a nucleic acid (DNA) provides the key to DIVERSITY among living organisms.


The code of life
The Code of Life… your traits.

  • The “code” of the chromosome is the SPECIFIC ORDER that bases occur.

    A T C G T A T G C G G…


Dna is wrapped tightly around histones and coiled tightly to form chromosomes
DNA is wrapped tightly around your traits.histones and coiled tightly to form chromosomes

See p. 297


How does DNA copy itself? your traits.

Purpose:DNA copies itself to ensure that each new cell that is produced in gets the correct number of chromosomes and receives an EXACT copy of the DNA molecule.

Replication must occur before cell division.


  • This is called your traits.DNA REPLICATION.

  • The DNA molecule serves as its own pattern or templateso as an exact copy can be made.


Watson and crick
Watson and Crick your traits.

  • The model that Watson and Crick where the nitrogen bases pair suggested a mechanism for DNA to replicate.


Messelson and stahl
Messelson and Stahl your traits.

  • They proved that DNA is semiconservative by attaching radioactive material to DNA. As the cell divided, they observed the new DNA in each cell and saw that it contained half of the old.

  • Semiconservative: contains half of the old strand when DNA is replicated.


STEPS OF DNA REPLICATION your traits.

1. Helicase begin to unzip the double helix at many different places. The hydrogen bonds between the bases are broken. Occurs in two different directions.

2. Free floating in the cytoplasm nucleotides pair with the bases on the template. DNA polyermasebonds together the nucleotides. Small segments are bonded together.



DNA Replication Video back together. DNA is called

http://www.youtube.com/watch?v=zdDkiRw1PdU&feature=player_embedded


Dna replication fork
DNA Replication Fork back together. DNA is called

Point where DNA is split apart to

replicate. Forms a Y!


Role of enzymes
Role of Enzymes back together. DNA is called

  • 1. Helicase unzips the two DNA strands.

  • 2. DNA polymerase is the enzyme that joins individual nucleotides to produce a new strand of DNA. Proofreads DNA when finished!


Dna replication in prokaryotic cells
DNA Replication in Prokaryotic Cells back together. DNA is called

  • 1. Proteins binds to starting point.

  • 2. Starts at a single point and proceeds in both directions.


Eukaryotic replication
Eukaryotic Replication back together. DNA is called

  • Since eukaryotic cells are so much bigger, the replication will start at dozens to hundreds of different places on the DNA.


DNA REPLICATION back together. DNA is called

What if there is a mistake?

There is always a chance that the wrong nucleotide bonds to another. HOWEVER, DNA polymerase is responsible for “reading” the bases and recognizing and replacing damaged or wrong nucleotides. This PROOFREADING allows for only one (1) error in ONE BILLION nucleotides.


Dna fingerprinting
DNA Fingerprinting back together. DNA is called

  • When DNA is found at a crime, the DNA is replicated many times to make enough to test. Once they have fingerprinted it, they can compare to find suspect.

  • Video

  • http://www.bing.com/videos/search?q=dna+crime+scene&view=detail&mid=684167203C024AD0C797684167203C024AD0C797&first=21&FORM=LKVR22&adlt=strict


Dna fingerprinting1
DNA Fingerprinting back together. DNA is called


Speed of dna replication
Speed of DNA Replication back together. DNA is called

  • In the human cell, 50 nucleotides can be added every second. It would that several days for replication to occur if the DNA did not start at several spots on the DNA so that it is occurring in many places on the DNA strand.


Transciption making of rna
Transciption – Making of RNA back together. DNA is called

  • Transcription – process of copying DNA to produce a complimentary strand of RNA. Transcription is making RNA from DNA

  • Purpose = to make RNA that is complimentary to the DNA


Types of RNA back together. DNA is called

There are three (3) types RNA:

1. Messenger RNA– (mRNA) carries messages from the DNA in the nucleus to the cytoplasm.

2. Transfer RNA– (tRNA) 20 different kinds which are only able to bond with one (1) specific type of amino acid.


Types of rna
Types of RNA back together. DNA is called

  • 3. Ribosomal RNA– (rRNA) major component (part) of the ribosomes


RNA TRANSCIPTION back together. DNA is called

Transcription – the process by which DNA makes RNA.

Steps in RNA Transcription:

  • A special enzyme tells DNA its time to make RNA.

  • The enzyme tells the nucleotides to only bond with RNA nucleotides.

  • -The code letters for RNA are: A, C, G and U.


Rna transciption
RNA TRANSCIPTION back together. DNA is called

3. Process occurs just like DNA replication

--When complete, only a single strand of RNA is formed UNLIKE DNA’s double strand.

--All three types of RNA are formed this way.

--All leave the nucleus and travel out into the cytoplasm.


Transcription video
Transcription Video back together. DNA is called

  • http://www.bing.com/videos/search?q=transcription&view=detail&mid=EE2661D88067BDEFF3E7EE2661D88067BDEFF3E7&first=0&FORM=LKVR8&adlt=strict


RNA TRANSLATION back together. DNA is called

Definition=Protein Synthesis: the formation of a protein using information coded on DNA and carried out by RNA in the assembly of amino acids.

Proteins are:

  • Amino acids in chains – 20 kinds

  • Made of 10’s or 100’s or 1000’s of amino acids

  • Must be arranged in a specific sequence for each type of protein

  • Function & type of protein is determined by amino acid sequence

  • DNA makes RNA

  • RNA orders the amino acids


RNA TRANSLATION back together. DNA is called

Translation Process:

  • mRNA goes to the ribosomes, tRNA

  • goes to the cytoplasm.

  • 2. tRNA picks up amino acids& brings them

  • to the ribosome.

  • 3. mRNA tells tRNA in which sequence to

  • assemble the proteins.(mRNA is the template!)

  • 4. An amino acid chain is a protein.


RNA TRANSLATION back together. DNA is called

So WHAT??:

RNA makes amino acid chains

DNA makes RNA

Amino acid chains make proteins

Proteins make cells


Go to gslc.genetics.utah.edu/units back together. DNA is called

Translate & Transcribe a Protein and

What is a Protein?


Translation
Translation back together. DNA is called

  • Groups of 3 nucleotides on the mRNA code for each amino acid to build a protein.

  • These groups of 3 are called: CODONS

  • The tRNA brings the correct amino acid to the chain.

  • You will build your own proteins tomorrow with the mRNA that you made yesterday!


We have been told that DNA is the blueprint for life, BUT what does that mean?

DNA holds the instructions that tell a cell how to construct amino acid chains.

That is important because amino acid chains build proteins.

Proteins build cells

AND


Steps to protein synthesis
Steps to Protein Synthesis what does that mean?

  • 1. DNA replication – make new DNA

  • 2. Transcription – DNA message given to RNA

  • 3. Translation – RNA is translated in amino acid chains(protein).


Prokaryotic protein synthesis
Prokaryotic - Protein synthesis what does that mean?

  • Location – cytoplasm

  • At the same time.

  • Eukaryotic – Protein synthesis


SO, HOW DOES AN AMINO ACID CHAIN GET BUILT? what does that mean?

Well, first we have to make something called RNA

RNA stands for ribonucleic acid

It differs from DNA in three ways:

1. RNA is single stranded.

2. The sugar in RNA is called ribose.

  • Uracil is one of the bases in RNA. There is NO thymine in RNA. This means A goes with U and G still goes with C.


Dna replication
DNA what does that mean?Replication

  • Replication: coping of DNA

  • The DNA molecule produces 2 IDENTICAL new complementary strands following the rules of base pairing:

    A-T, G-C

  • Each strand of the original DNA serves as a template for the new strand


Semiconservative model
Semiconservative Model what does that mean?

  • Replication is called semiconservation because one strand of DNA is used to as a template to make the new DNA.


Steps of dna replication

DNA Template what does that mean?

Parental DNA

New DNA

Steps of DNAReplication

1.DNA unzips and the hydrogen bonds between the nitrogen bases pulled apart. The base pairs are separated and are left exposed. This occurs in two different directions. This occurs along hundreds of different places at a time.

.


Steps of replication
Steps of Replication what does that mean?

2. Free-floating nucleotides are paired up to the free nucleotides. DNA polymerase bond the nucleotides together.

3.Two identical strands result. DNA polymerase checks for mistakes when complete.


Dna replication1
DNA Replication what does that mean?

  • DNA has 80 million base pairs in a chromosomes. DNA is copied at about 50 base pairs per second. This would take a month if replication did not occur at hundreds of different places at once.


Replication Quiz what does that mean?

1. Why is replication necessary?

2. Describe how replication works.

3. Use the complementary rule to

create the complementary strand:

A---?

G---?

C---?

T---?

A---?

G---?

A---?

G---?

C---?

A---?

G---?

T---?


Replication Quiz what does that mean?

1. Why is replication necessary?

So both new cells will have the correct DNA

2. When does replication occur?

During interphase (S phase).

3. Describe how replication works.

Enzymes unzip DNA and complementary nucleotides join each original strand.

4. Use the complementary rule to

create the complementary strand:

A---T

G---C

C---G

T---A

A---T

G---C

A---T

G---C

C---G

A---T

G---C

T---A


1961 watson crick proposed
(1961) what does that mean? Watson & Crick proposed…

  • …DNA controlled cell function by serving as a template for PROTEIN structure.

  • 3 Nucleotides = a triplet or CODON

    (which code for a specific AMINO ACID)

    See p.303

  • AMINO ACIDS are the building blocks of proteins.


Dna transcription
DNA what does that mean?Transcription

  • DNA can “unzip” itself and RNA nucleotides match up to the DNA strand.

  • Both DNA & RNA are formed from NUCLEOTIDES and are called NUCLEIC acids.

See p.301


Dna translation
DNA what does that mean?Translation

  • The cell uses information from “messenger” RNA to produce proteins

See p.304-305

We will discuss details of this on a later date


Types of nitrogen base pairs
Types of Nitrogen Base Pairs what does that mean?

DNA

  • Adenine w/ thymine

  • Cytosine w/ guanine

RNA

  • Uracil w/adenine

  • Cytosine w/guanine


Caugca
CAUGCA what does that mean?


Transcription translation quiz
Transcription/Translation Quiz what does that mean?

  • identify the amino acids coded for by these codons:

    UGGCAGUGC

    ACCGUCACG


1. Why is transcription necessary? what does that mean?

Transcription SIGNALS messenger RNA (mRNA) to carry the code for proteins out of the nucleus, to the ribosomes in the cytoplasm.

2. Describe transcription.

RNA polymerase binds to DNA, separates the strands, then uses one strand as a template to assemble MRNA.

3. Why is translation necessary?

Translation assures that the right amino acids are joined together by peptides to form the correct protein.


4. Describe translation. what does that mean?

The cell uses information from MRNA to produce proteins.

5. What are the main differences between DNA and RNA.

DNA has deoxyribose, RNA has ribose; DNA has 2 strands, RNA has one strand; DNA has thymine, RNA has uracil.

  • Using the chart on page 303, identify the amino acids coded for by these codons: UGGCAGUGC

    tryptophan-glutamine-cysteine



Amazing dna facts
AMAZING DNA FACTS… what does that mean?

  • DNA from a single human cell extends in a single thread for almost 2 meters long!!!

  • It contains information equal to some 600,000 printed pages of 500 words each!!!

    (a library of about 1,000 books)


Let s review dna lm p 44
LET’S REVIEW DNA… what does that mean?LM p.44

  • List the conclusions Griffith & Avery, Hershey & Chase drew from their experiments.

  • Summarize the relationship between genes & DNA.

  • Describe the overall structure of the DNA molecule.

  • What are the 4 kinds of bases?


Reading questions
Reading Questions: what does that mean?

  • Are RNA Polymerase the same as DNA polymerase?

  • What role do “Promoters” have in transcription?


Snork activity directions
SNORK ACTIVITY DIRECTIONS what does that mean?

  • TURN TO THE “DNA, RNA & SNORKS” PAGE IN PACKET:

  • READ THE 2 PARAGRAPHS ABOVE THE TABLE, AND THE 3RD PARAGRAPH BELOW THE TABLE.


AUA, UCG, GGC, UAU what does that mean?


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