11 1 genes are made of dna
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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.

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11.1 Genes are made of DNA

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11 1 genes are made of dna

11.1 Genes are made of DNA


Griffith experiment

Griffith Experiment


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


Hershey chase experiment

Hershey Chase Experiment


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


Dna into chromosomes

DNA into chromosomes


Nitrogenous bases

Nitrogenous Bases


Dna structures

DNA- structures


Dna nucleotide

DNA Nucleotide


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 replication

DNA Replication


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


Dna replication3

DNA Replication


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.)


Dna rna1

DNA & RNA


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)


Dna to protein

DNA to Protein


Table of codons

Table of Codons


11 5 there are two main steps from genes to proteins

11.5 There are two main steps from genes to proteins


Transcription base pairing of mrna with dna

Transcription: Base Pairing of mRNA with DNA


Rna transcription

RNA Transcription


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)


Rna editing

RNA editing


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)


Adding amino acids to a polypeptide chain

Adding Amino Acids to a Polypeptide Chain


Initiation translation

Initiation Translation


Elongation translation

Elongation Translation


Termination translation

Termination Translation


Steps of translation

Steps of Translation

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

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

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

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


11 6 mutations can change the meaning of genes

11.6 Mutations can change the meaning of genes


Point vs frameshift mutations

Point vs. Frameshift Mutations


Chromosome mutations

Chromosome Mutations


How mutations affect genes

How mutations affect genes

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?

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

Cancers

Gametes

Birth defects

Genetic disorders

Mutations Effects


Ch 11 test

Ch. 11 Test

  • Vocabulary

  • DNA & RNA structure

  • Replication, transcription, translation- content and problems

  • Scientists & experiments involved

  • Mutations & mutagens- types and effects


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