DNA Deoxyribonucleic Acid “The Blueprint of Life”
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Transcript of DNA Deoxyribonucleic Acid “The Blueprint of Life”
DNA Deoxyribonucleic Acid
“The Blueprint of Life”
A. What is DNA?
1. Organic molecule
2. Nucleic acid
B.Where is it
located?1. Nucleus2. In the Chromosomes
DNA
Chromosomes in Nucleus
C. Structure of DNA
1.Nucleotidesa. Phosphateb. Deoxyribose sugarc. Nitrogenous bases:
Adenine-ThymineGuanine-Cytosine
2. Ladder Shape 3. Double strand, helix
twist
Ladder Shape (Sides & Rungs)
Sides:PhosphateSugarPhosphate
Rungs:A-TT-AG-CC-G
Watson & Crick’s Double helix:
D. What is DNA’s Function?
Hereditary InstructionsChemical code for every trait“Blueprint” for making Proteins
Chromosome DNA Code:
Genes =Segments of DNA Code for a trait
HairColor
EyeColor
DNA Chromosome Code:
A triplet of bases code for an amino acidA series of amino acids code for a proteinThe protein codes for a
Trait
Acid AcidSugar-T-A-SugarAcid AcidSugar-G-C-SugarAcid AcidSugar-C-G-Sugar
DNA Chromosome Code:Like Morse Code: Hair =
*** *- ** *-*Or DNA
A-T
A-T
G-C
C-G
T-A
C-G
DNA ReplicationChromosomes doubleInterphaseS or Synthesis stage 2N
1N
E. Steps for DNA Replication:
1. DNA untwists2. DNA unzips-hydrogen bonds are
broken by enzyme3. Corresponding nucleotides line up and hydrogen bonds form between nitrogen bases 4. 2 strands twist into helix5. Result is 2 chromosomes- part old and part new
IdenticalStrand
A. What is RNA?1.Organic
Molecule2.Nucleic Acid3.Types:mRNA=messengertRNA=transferrRNA=ribosomal
B. Where is RNA located?
1.mRNA in
nucleus & cytoplasm
2.tRNA only in cytoplasm
3.rRNA at the ribosomes
B. What is RNA’s structure?
PhosphateSugar-BasePhosphateSugar-BasePhosphateSugar-BasePhosphateSugar-Base
1.Nucleotides=a. Phosphateb. Ribose sugarc. Nitrogenous
Bases: Adenine-UracilGuanine-Cytocine
2. Single Strand3. No Twisted helix
Comparison of RNA & DNA:
PhosphateSugar-BasePhosphateSugar-BasePhosphateSugar-BasePhosphateSugar-Base
PhosphatePhosphate
Sugar----Bases----Sugar
Phosphate Phosphate
Sugar----Bases----Sugar
Phosphate Phosphate
Sugar----Bases----Sugar
Phosphate Phosphate
RNA DNA Ladder
Deoxy-ribose
Ribose
Double StrandedSingle Stranded
Uracil replaced thymine
D. What are RNA’s functions:
1.mRNA=Copies the DNA codeDeliveries message to RibosomeRibosomes-Protein Factories
Why not send the original DNA code out?
DNA might be damaged!mRNA components are reusedTo copy more messages
Original DNA
mRNA copy
RNA function cont.2. tRNA:
in cytoplasmPicks up an amino acid“Taxis” the aa to the Ribosome protein factories
tRNA
Aminoacid
III. Protein Synthesis
Assembling Proteins from the DNA Instructions
A. Transcription:
1.mRNA is copied off of DNA
2. In nucleus3.Steps:
DNA untwistsDNA unzipsRNA codons line up
Transcription:mRNA has:Ribose sugarUracil instead of thymine basesNuclear membrane allows it to leave!DNA Code
mRNAA
T
C
G
U
A
G
C
Transcription in The nucleus
mRNA copyDNA
B. Translation =Conversion of the message (mRNA Code)Into a proteinBy the ribosome factories
B.Translation
1.mRNA arrives at the Ribosome
2.tRNA picks up an amino acid
3.tRNA delivers the aa to the ribosome
4.aa are assembled into polypeptide proteins
U A G C
GC
U
A
mRNA code
tRNA taxi
• tRNA delivers
amino acid
2. Peptide bond forms
3. tRNA leaves ribosome
4. PolypeptideChain of aminoacids grows
Summary:
DNA Replication:Make duplicate DNAIn nucleusCopy the chromosomesFor Mitosis
Protein Synthesis:
1.Transcrition:Make mRNAFrom DNA
2.Translation:Make proteinOff mRNA codeUsing amino acids