DNA DNA --The Blueprint of --The Blueprint of Life Life DEOXYRIBONUCLEIC ACID “ “ The Twisted The Twisted Ladder” Ladder” “ “ The Double The Double Helix” Helix”
Jan 01, 2016
DNADNA--The Blueprint of Life--The Blueprint of Life
DEOXYRIBONUCLEIC ACID
““The Twisted Ladder”
The Twisted Ladder”
““The Double Helix”
The Double Helix”
The Genetic Code
• Genetic - relates to heredity• Heredity - The passing of traits from
the parents to their young.• Traits - Characteristic that a living
thing can pass on to its young, (eye color)
• Characteristic - A description of a trait , (blue eyes)
The Genetic Code
• Genetic code - is the store information that is passed from one generation to the next.
• Transformation - the exchange of genetic information between 2 different (but similar) organisms.
The Genetic Code
• Transforming Factor - A scientist named Avery discovered through experimentation that DNA is the molecule responsible for transformation .
The Structure of DNA
• Nucleotide - The base unit of structure to form the DNA molecule
• Three basic parts of a nucleotide– 1. Deoxyribose - a sugar made of 5
carbon atoms– 2. Phosphate group– 3. Nitrogenous, or nitrogen base
The Structure of DNA
• Nitrogenous Bases– PURINES - PYRIMIDINES
• Adenine *Cytosine• Guanine * Thymine
The Structure of DNA
• Nucleotides form long chains using the deoxyribose (sugar) and the phosphate groups as the backbone and the nitrogenous bases stick out from the chain.
The Structure of a Nucleotide
Phosphategroup
Deoxyribose(sugar)
Nitrogenousbase
The Nucleotide--A more Technical View
The Structure of Organic The Structure of Organic BasesBases
Adenine
Guanine
Thymine Cytosine
PURINES
PYRIMIDINES
The Structure of DNA
The Structure of DNA• The Double Helix
– Watson and Crick discovered the twisting (spiral shape) of the DNA molecule.
– Stole the research from Rosalind Franklin to determine the shape
– Stole the research from Erwin Chargaff to determine the arrangement of the purines and pyrimidine bases
The Structure of DNA
• Watson and Crick won the Nobel Prize in 1962 for their discoveries.
• Why didn’t Rosalind Franklin earn the Nobel Prize?
The Replication Of DNA
• Base Pairing– Thymine will only bond to Adenine in
the DNA molecule
– Cytosine will only bond with Guanine in the DNA molecule
The Replication Of DNA
Base Pairing (Naming of Bases)
• Thymine ( T )• Cytosine ( C )• Guanine (G)• Adenine ( A )
The Replication Of DNA
• Base Pairing– To show a nucleotide chain it is
abbreviated A-C-T-G-T-A-T-A-T-C-G-C-C-G– To each of the bases above they would
have the matching base belowT-G-A-C-A-T-A-T-A-G-C-G-G-C– These are the opposite base
nucleotides
The Replication Of DNA
• Base Pairing
“A” to “T” is a double bond
“C” to “G” is a triple bond
These Hydrogen bonds make the molecule twist
The Replication of DNA
• Replication - the process in which DNA makes a copy of itself before the cell can divide.
• This process ensures that the two new daughter cells have the same DNA
Replication Process
Replication Process
Replication Process
Replication Process
Replication Process
Replication Process
Replication Process
Replication Process
Replication Process
Replication Process
Replication Process
Replication Process
Replication Process
Replication Process
It is Quiz Time
Please take out a clean sheet of paper
Question 1
• What does the abbreviation DNA stand for? Please spell it the best you can!
Question 2
• True or False• An example of a trait is “hair color”
Question 3
• True or False• If someone tells you that you have
beautiful brown eyes, they are complimenting a characteristic.
Question 4
• True or False• Heredity is the passing of a trait
from the parents to the offspring
Question 5
• What did “Avery” discover in his experiments?
• A. Protein is the transforming factor
• B. DNA is the transforming factor• C. RNA is the transforming factor
Question 6
• Fill in the blank• The base unit of structure that
makes up the DNA molecule is the _____________. It contains 3 basic parts
Question 7
• What are the nitrogen bases that make up the purines?– adenine– thymine– cytosine– guanine
Question 8
• What are the nitrogen bases that make up the pyrimidines?– adenine– thymine– cytosine– guanine
Question 9
• What 2 parts of the DNA molecule builds the backbone?– Phosphate group– Deoxyribose Sugar– Nitrogen Base– Purines– Pyrimidines
Question 10
• What did Watson and Crick steal from Rosalind Franklin?
Question 11
• What did Watson and Crick steal from Erwin Chargaff?
Question 12
• What did Waston and Crick earn for all their hard work?
Question 13
• Why didn’t Rosalind Franklin earn the same prize?
Question 14
• What two nitrogen base pairs always pair together in the DNA molecule?– Please write the entire base name out
• spell the best you can
Question 15
• What is the abbreviation for the following nitrogen bases– 1. Adenine– 2. Thymine– 3. Guanine– 4. Cytosine
Question 16
• Why must a cell replicate it’s DNA before it divides?
Question 17
• Copy the DNA strand on your paper
• Write the complementary nitrogen base to the DNA strand
• A-T-C-C-G-T-C-A-T
Question 18
• What is needed to break the hydrogen bonds between the nitrogen bases when the strand starts to replicate?
RNA; Lecture II
Ribonucleic Acid
RNA
• RNA is the messenger between DNA and the ribosomes.
• The message from the DNA will tell the ribosomes what protein to synthesize.
RNA Structure
• RNA has the same structure as DNA with the Sugar- phosphate group backbone.
• 3 difference between RNA and DNA• 1. The sugar group in RNA is called
“ribose” where DNA is “deoxyribose”• 2. RNA is a single strand of nucleotides
where DNA is a double strand of nucleotides
RNA Structure
• 3. RNA has “Uracil” instead of “thymine” in which DNA contains.
• RNA does follow the same base pairing rules that DNA follows. DIFFERENCE, “Uracil” pairs with “Adenine” just like “thymine did in DNA.
• Uracil is abbreviated “U”
The Reason for RNA
• Because the DNA molecule is to large to exit the nuclear membrane so it makes a copy of itself in single strand (RNA), a smaller molecule, to relay the commands for protein synthesis to the ribosomes.
• This type of RNA that delivers the commands from the DNA is called, “messenger RNA” abbreviated mRNA
Transcription
• Synthesizes RNA from a DNA strand.
• The RNA is “transcribed” by copying a portion of DNA to make a complementary strand of RNA.
• Transferring DNA to RNA
Transcription
The Process of Transcription.1. RNA polymerase (an enzyme)
attaches itself to a section the DNA molecule that needs transcribed.
2. RNA polymerase causes the DNA molecule two strands to separate
3. The RNA polymerase pulls in floating nucleotide to form the mRNA from the DNA template.
Transcription
C
A
T
G
G
C
T
A
A
T
Transcription
C
A
T
G
G
C
T
A
A
T
Transcription
C
A
T
G
G
C
T
A
A
T
Transcription
C
A
T
G
G
C
T
A
A
T
Transcription
C
A
T
G
G
C
T
A
A
T
A
Transcription
C
A
T
G
G
C
T
A
A
T
A
Transcription
C
A
T
G
G
C
T
A
A
T
A U
Transcription
C
A
T
G
G
C
T
A
A
T
A U
G
Transcription
C
A
T
G
G
C
T
A
A
T
A U
G
Transcription
C
A
T
G
G
C
T
A
A
T
A U G
Transcription
C
A
T
G
G
C
T
A
A
T
A U G
Transcription
C
A
T
G
G
C
T
A
A
T
A U G
C
Transcription
C
A
T
G
G
C
T
A
A
T
AU GC
Transcription
C
A
T
G
G
C
T
A
A
T
AU G C
Transcription
C
A
T
G
G
C
T
A
A
T
AG C
U
Transcription
C
A
T
G
G
C
T
A
A
T
AG C
U
Transcription
C
A
T
G
G
C
T
A
A
T
AG CU
Transcription
C
A
T
G
G
C
T
A
A
T
AC U
Transcription
C
A
T
G
G
C
T
A
A
T
AU
Transcription
C
A
T
G
G
C
T
A
A
T
A
Transcription
C
A
T
G
G
C
T
A
A
T
A
Transcription
C
A
T
G
G
C
T
A
A
T
A
Transcription
CA
TG
G
C
T
A
A
T
A
Transcription
CA
TG
G
C
T
A
A
T
A
Transcription
• NOTE• The mRNA made a copy of one
side of the DNA molecule• The mRNA now leaves the nucleus
and travels to ribosome out in the cytoplasm tell the ribosome what protein to make.
Protein Synthesis
• A “Protein” is a string of “Amino Acids” when put together form a molecule called a “polypeptide”
• There are 20 different types of Amino Acids
• The arrangement of the nucleotides codes for which Amino Acid is needed to form a certain polypeptide.
Protein Synthesis
• Review• DNA contains the following
nucleotide bases ( A, T, C, G )• RNA contains the following
nucleotide bases ( A , U, C, G )
Protein Synthesis
• It takes “3” nucleotides to code for one Amino Acid.
• Each combination of “3” nucleotides on mRNA is called a “Codon”
• There can be more than one codon for each amino acid.
Protein Synthesis
A U G U C C A U C G G C U G A
CODON CODON CODON CODON CODON
Look at Your Handout
First Letter of Sequence
mRNA
Second Letter of Sequence
mRNA
Third Letter of Sequence
mRNA
Protein Synthesis
• Note• AUG is a “initiator” that always codes
for Methionine (amino acid) which is a start code for protein synthesis.
• However, there are 3 codons, UAA, UAG, and UGA, that do not code for an amino acid and ends the protein synthesis. They are “stop” codons. Just like a period.
Protein Synthesis
• Look at the handout• What amino acid do the following
codons call for?• AGC• GGG• CUC• UGA
Protein Synthesis
• Look at the handout• What amino acid do the following
codons call for?• AGC serine• GGG glycine• CUC leucine• UGA “stop” codon
Translation
• The process of translating the message from the mRNA into a polypeptide chain.
• The amino acids are carried to the mRNA on a specialized molecule called transfer RNA (tRNA).
Translation
A U G
Amino Acid
Anticodon
Translation
• The role of ribosomes in translation• Ribosomes pass along the mRNA
and calls out the tRNA to bring in the anticodon match to mRNA codon
• Remember the amino acid needed for the polypeptide is attached to tRNA
Translation
mRNA
A U G C G U A G C A C U A G
Translation
mRNA
A U G C G U A G C A C U A G
Translation
mRNA
A U G C G U A G C A C U A G
Translation
mRNA
A U G C G U A G C A C U A G
U A C
Translation
mRNA
A U G C G U A G C A C U A G
U A C
Translation
mRNA
A U G C G U A G C A C U A G
U A C
Translation
mRNA
A U G C G U A G C A C U A G
U A C
Translation
mRNA
A U G C G U A G C A C U A G
G C A
Translation
mRNA
A U G C G U A G C A C U A G
G C A
Translation
mRNA
A U G C G U A G C A C U A G
G C A
Translation
mRNA
A U G C G U A G C C U A
U C G
Translation
mRNA
A U G C G U A G C U G A
U C G
Translation
mRNA
A U G C G U A G C U G A
U C G
Translation
mRNA
A U G C G U A G C U G A
U C G
Translation
mRNA
A U G C G U A G C U G A
U C G
Translation
mRNA
A U G C G U A G C U G A
U C G
Stop Codon
Translation
mRNA
A U G C G U A G C U G A
Stop Codon
Let’s review
• If DNA copies itself it is called……..• When DNA makes a copy of mRNA
it is called ……...• When mRNA calls for an amino
acid it is called ……..
Let’s review
• If DNA copies itself it is called……..• replication• When DNA makes a copy of mRNA it
is called ………• transcription• When mRNA calls for an amino acid it
is called ……..• translation
Let’s review
• DNA strand• T A C C C G A T C A C T• mRNA strand (CODON)• A U G G G C U A G U G A• tRNA strand (ANTICODON)• U A C C C G A U C A C U
Let’s review
• Very Important• Remember the mRNA codon codes
for the amino acid• Always look at the mRNA when
looking to see what amino acid is needed
Let’s review
• What amino acid do each of the DNA strands code for?
• ATT • GGC• AGA• TTG
Let’s review
• What amino acid do each of the DNA strands code for?
• DNA mRNA Amino Acid• ATT UAA stop• GGC CCG Proline• AGA UCU Serine• TTG AAC Asparagine
Let’s review
• What would the tRNA anticodon for each of the amino acids?
• Amino Acid• stop• Proline• Serine• Asparagine
Let’s review
• What would the tRNA anticodon for each of the amino acids?
• Amino Acid tRNA• stop AUU• Proline GGC• Serine AGA• Asparagine UUG
The End
Time for your DNA/RNA 3 dimensional project
3-D project
• You will choose one of the three processes we discussed in lecture to build a 3-D model demonstrating the process.
• 1. Replication• 2. Transcription• 3. Translation
The model must contain ………..• 1. A 3-D display of the process
chosen• 2. A “key” for reference• 3. An explanation of the process
chosen• NO food materials are to be used
Deadline
• Tuesday/Wednesday (2/20, 2/21)• It is due Tuesday/Wednesday• Tuesday/Wednesday• If you are ill, have someone bring it to
me.• NO EXCUSES for late assignments• will not take them after 3:30
Tuesday/Wednesday