DNA
description
Transcript of DNA
DNADNABiology – Mr. FemiaBiology – Mr. Femia
HeredityHeredity
The genetic information that makes you look the way you do
The genetic information that makes you look the way you do
InheritInherit
You inherit information from your parents
You inherit information from your parents
Nucleic AcidNucleic Acid
Molecules that store information about heredity in cell
Molecules that store information about heredity in cell
Examples of nucleic acidExamples of nucleic acid
DNA Only in the nucleus
Phosphate Sugar –Deoxyribose Nitrogen bases
(ATCG)
A – adenineT – thymineG – guanineC- cytosine
DNA Only in the nucleus
Phosphate Sugar –Deoxyribose Nitrogen bases
(ATCG)
A – adenineT – thymineG – guanineC- cytosine
RNA From the nucleus to
the cytoplasm Phosphate Sugar- Ribose Nitrogen bases (AUCG)
AU – uracilCG
RNA From the nucleus to
the cytoplasm Phosphate Sugar- Ribose Nitrogen bases (AUCG)
AU – uracilCG
DNA RNA DNA RNA
phosphate
Sugar nitrogen base
phosphate
Sugar nitrogen base
phosphate
Sugar nitrogen base
phosphate
Sugar nitrogen base
Complimentary Base Pairing
Complimentary Base Pairing
Adenine always pairs with Thymine or Uracil
A---T or U
Guanine always pairs with Cytosine
G---C
Adenine always pairs with Thymine or Uracil
A---T or U
Guanine always pairs with Cytosine
G---C
A---T C---GA---T C---G
Shape - Double HelixShape - Double Helix
Nucleotides pair up and twist to form a spiral staircase
Nucleotides pair up and twist to form a spiral staircase
Discovered by Watson and Crick
Discovered by Watson and Crick
Genetic CodeGenetic Code
The sequence of different nitrogen bases along one strand of DNA is a code for protein.
The sequence of different nitrogen bases along one strand of DNA is a code for protein.
CodonCodon
Nucleotides are arranged into groups of three.
Also called triplets – 2 nitrogen bases
Nucleotides are arranged into groups of three.
Also called triplets – 2 nitrogen bases
Amino acidsAmino acids
Each codon represents one of the 20 different amino acidsAAA ATT AAT
Each codon represents one of the 20 different amino acidsAAA ATT AAT
So…So…
Every 3 nitrogen bases make up one codon
Every codon codes for a specific amino acid
Many amino acids bonded together make up a protein
Every 3 nitrogen bases make up one codon
Every codon codes for a specific amino acid
Many amino acids bonded together make up a protein
Amino Acids are put together to make proteins
Amino Acids are put together to make proteins
Examples FingernailsHairSkinMuscles
Examples FingernailsHairSkinMuscles
So…….So…….
DNA is important because it helps determine the proteins that you are made of!
DNA is important because it helps determine the proteins that you are made of!
Replication of DNAReplication of DNA
Remember….Heredity is the passing of information from parents to you
This information must also be passed form one cell to the next when new cells are made (during which process?)
So……DNA must be replicated.
Remember….Heredity is the passing of information from parents to you
This information must also be passed form one cell to the next when new cells are made (during which process?)
So……DNA must be replicated.
The GoalThe Goal
DNA replication - must make sure each cell in the same organism has exactly the same copy of DNA
DNA replication - must make sure each cell in the same organism has exactly the same copy of DNA
MutationMutation
Is it possible for there to be a mistake when replicating DNA?
Is it possible for there to be a mistake when replicating DNA?
MutationMutation
Can result in CancerRetardationSterilityPhysical
alterations
Can result in CancerRetardationSterilityPhysical
alterations
Germ Cell Tumor
Germ Cell Tumor
CausesCauses
Exposure to SunRadiationChemicalsOr a simple
mistake
Exposure to SunRadiationChemicalsOr a simple
mistake
Replication of DNAthe process of copying DNA in a
cell
Replication of DNAthe process of copying DNA in a
cellWhy?
In order for a cell to divide, it must first have 2 copies of DNA
One for the original cell and one for the new cell
Why?In order for a cell
to divide, it must first have 2 copies of DNA
One for the original cell and one for the new cell
ReplicationReplication
Replication Fork
The point where the double helix opens or unzipsA enzyme
unzips the double helix
Replication Fork
The point where the double helix opens or unzipsA enzyme
unzips the double helix
ReplicationReplication
Another enzyme puts free nucleotides into the correct place
Another enzyme puts free nucleotides into the correct place
Semi Conservative Replication
Semi Conservative Replication
Each new double helix that is formed consists of one old strand of DNA and one new strand
Notice the old molecule was blue and a new molecule still has a blue strand
Each new double helix that is formed consists of one old strand of DNA and one new strand
Notice the old molecule was blue and a new molecule still has a blue strand
Let’s see this in action…Let’s see this in action…
http://www.johnkyrk.com/DNAreplication.html
http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/dna-rna2.swf
http://www.dnai.org/
http://www.johnkyrk.com/DNAreplication.html
http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/dna-rna2.swf
http://www.dnai.org/