11 1 genes are made of dna
Download
1 / 50

11.1 Genes are made of DNA - PowerPoint PPT Presentation


  • 136 Views
  • Uploaded on

11.1 Genes are made of DNA. Griffith Experiment. Avery Experiment. -Destroyed proteins -Mice still died with mix. Hershey Chase Experiement. Virus- nucleic acid wrapped in protein; needs host to reproduce Bacteriophage- virus that infects bacteria. Hershey Chase Experiment. Question 1 & 2.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about '11.1 Genes are made of DNA' - colin


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript


Avery experiment
Avery Experiment

-Destroyed proteins

-Mice still died with mix


Hershey chase experiement
Hershey Chase Experiement

  • Virus- nucleic acid wrapped in protein; needs host to reproduce

  • Bacteriophage- virus that infects bacteria



Question 1 2
Question 1 & 2

  • Explain how experiments done by Griffith, Avery & Hershey and Chase supported that genes are made of DNA? [4 points]

    2. Identify the parts of DNA and how the double helix is put together (bases)? [4 points]


11 2 nucleic acids store information in their sequences of chemical units

11.2 Nucleic acids store information in their sequences of chemical units






Rosalind franklin maurice wilkins
Rosalind Franklin & Maurice Wilkins

1950’s photographs of the DNA molecule using X-ray crystallography which showed the shape to be a helix


Erwin chargaff
Erwin Chargaff

  • 1951, proved that the % of A = T and % of G = C


Watson crick
Watson &Crick

  • 1953, used data from the other scientists and built models to finally figure out the exact structure of DNA

  • 1962 won the nobel prize in Medicine


11 3 dna replication is the molecular mechanism of inheritance

11.3 DNA replication is the molecular mechanism of inheritance



Dna replication1
DNA Replication

  • Enzymes are protein molecules that catalyze chemical reactions in a cell – usually any protein ending in “ase” is an enzyme

  • Helicase- unwinds DNA

  • DNA Polymerase 3 () - Adds complementary nucleotide

  • DNA Polymerase 1 ()- Checks for error

  • Single strand bind proteins- help hold open DNA


Dna replication2
DNA Replication

  • DNA primase- makes an initiation (starting) site for replication

  • RNA primer- short segment of RNA where DNA replication starts

  • DNA ligase- binds two nucleotides together

  • Topoisomerase (gyrase)- relaxes and recoils helix



11 4 a gene provides the information for making a specific protein

11.4 A gene provides the information for making a specific protein


Dna rna

Deoxyribose sugar

A,T,C,G

Double strand

Stays in Nucleus

DNA

Ribose sugar

A,U,C,G

Uracil pairs with adenine

Single strand

Nucleus to cytoplasm

Messenger (mRNA), transfer (tRNA), ribosomal (rRNA)

DNA & RNA


Types of rna
Types of RNA

  • mRNA - Messenger RNA: Encodes amino acid sequence of a polypeptide.

    • tRNA - Transfer RNA: Brings amino acids to ribosomes during translation.

    • rRNA - Ribosomal RNA: With ribosomal proteins, makes up the ribosomes, the organelles that translate the mRNA.

  • • snRNA - Small nuclear RNA: With proteins, forms complexes that are used in RNA processing in eukaryotes. (Not found in prokaryotes.)



Beadle and tatum
Beadle and Tatum

  • Beadle and Tatum discovered when looking at mutant Neurospora crassa (bread mold)

  • Individual gene produces a specific enzyme

  • One gene - one polypeptide (combinaiton of amino acids)




11 5 there are two main steps from genes to proteins

11.5 There are two main steps from genes to proteins




Steps of transcription
Steps of Transcription

1. DNA double helix unwound and separated by RNA polymerase

2. RNA polymerase adds RNA nucleotides together, making a single strand of mRNA which is complementary to 1 strand of the DNA


Steps of transcription1
Steps of Transcription

3. mRNA is processed (modified) before leaving the nucleus

  • introns (non coding regions) are cut out of the mRNA

  • exons (coding regions) are “spliced” together to form the

    final mRNA product

    4. Introns are cut out and exons are spliced together to form the final copy of messenger RNA (mRNA)



11 1 genes are made of dna

  • Most eukaryotic protein-coding genes contain segments called introns, which break up the amino acid coding sequence into segments called exons. The transcript of these genes is the pre-mRNA (precursor-mRNA).The pre-mRNA is processed in the nucleus to remove the introns and splice the exons together into a translatable mRNA. That mRNA exits the nucleus and is translated in the cytoplasm.


Transfer rna trna
Transfer RNA (tRNA) introns, which break up the amino acid coding sequence into segments called exons.


Adding amino acids to a polypeptide chain
Adding Amino Acids to a Polypeptide Chain introns, which break up the amino acid coding sequence into segments called exons.


Initiation translation
Initiation Translation introns, which break up the amino acid coding sequence into segments called exons.


Elongation translation
Elongation Translation introns, which break up the amino acid coding sequence into segments called exons.


Termination translation
Termination Translation introns, which break up the amino acid coding sequence into segments called exons.


Steps of translation
Steps of Translation introns, which break up the amino acid coding sequence into segments called exons.

1. mRNA leaves the nucleus and is transported to the ribosome where translation takes place

2. Ribosome holds onto the mRNA, the mRNA codon AUG is located in the P site of the ribosome

3. tRNA carries an amino acid to the P site of the ribosome

4. Another tRNA carries the next amino acid to the A site of the ribosome


Steps of translation1
Steps of Translation introns, which break up the amino acid coding sequence into segments called exons.

5. Two amino acids are joined together with a peptide bond

6. tRNA in the P site leaves

7. Ribosome moves along the mRNA until the next codon is located in the A site

(the tRNA which was located in the A site is now in the P site and is holding the peptide chain)

8. tRNA carries the next amino acid to the A site


Steps of translation2
Steps of Translation introns, which break up the amino acid coding sequence into segments called exons.

9. New amino acid is joined to the peptide chain (the polypeptide is made of 3 amino acids)

  • tRNA in the P site leaves

    11. Process continues until a stop codon appears in the A site of the ribosome

    12. Polypeptide is now complete


Rules for translation
Rules for translation introns, which break up the amino acid coding sequence into segments called exons.

1. Codon is a three-base “word” that codes for one amino acid

2. Determine the amino acid coded for by an mRNA codon use the genetic code

3. Genetic code is universal – all species use the same genetic code, the same 20 amino acids are used in all living organisms


Summary of translation process
Summary of Translation Process introns, which break up the amino acid coding sequence into segments called exons.


11 6 mutations can change the meaning of genes

11.6 Mutations can change the meaning of genes introns, which break up the amino acid coding sequence into segments called exons.


Point vs frameshift mutations
Point vs. Frameshift Mutations introns, which break up the amino acid coding sequence into segments called exons.


Chromosome mutations
Chromosome Mutations introns, which break up the amino acid coding sequence into segments called exons.


How mutations affect genes
How mutations affect genes introns, which break up the amino acid coding sequence into segments called exons.

1. A mutation is any change in the nucleotide sequence of DNA.

2.Two categories of mutations

a. Base substitutions (point)– replacement of one nucleotide with another

i. This can change the protein or not change the protein

b. Base insertions or base deletions (frameshift) – addition of an extra nucleotide or subtracting a nucleotide

i. Have more effect on the protein than a substitution


What causes mutations
What causes mutations? introns, which break up the amino acid coding sequence into segments called exons.

1. Mistakes during DNA replication can cause mutations

2. Mutagens – physical or chemical agents that cause mutations

a. Physical mutagens – high energy radiation, X-rays, Ultraviolet light

b. Chemical mutagens – chemicals that are similar to DNA bases and cause incorrect base-pairing


Mutations effects

Body Cells introns, which break up the amino acid coding sequence into segments called exons.

Cancers

Gametes

Birth defects

Genetic disorders

Mutations Effects


Ch 11 test
Ch. 11 Test introns, which break up the amino acid coding sequence into segments called exons.

  • Vocabulary

  • DNA & RNA structure

  • Replication, transcription, translation- content and problems

  • Scientists & experiments involved

  • Mutations & mutagens- types and effects