Download DNA Deoxyribonucleic Acid

DNA Deoxyribonucleic Acid
“The Blueprint of Life”
I. DNA Structure & Function
A. What is DNA?
1. Organic
molecule
2. Nucleic acid
B.Where is it located?
1. Nucleus
2. Chromosomes
Chromosomes in Nucleus
C. Structure of DNA

Nucleotides
a. Phosphoric Acid
b. Deoxyribose sugar
c. Nitrogenous bases:
Adenine-Thymine
Guanine-Cytosine
2. Ladder Shape
3. Double strand, helix twist
Ladder Shape (Sides & Rungs)
Sides:
 Phosphoric Acid
 Sugar
 Phosphoric Acid
Rungs:
 A-T
 T-A
 G-C
 C-G
Watson & Crick’s Double helix:
D. What is DNA’s Function?
 Hereditary Instructions
 Chemical code for every trait
 “Blueprint” for making Proteins
- Proteins are groups of amino acids linked together and folded up.
- Proteins are responsible for all of the traits that living things possess.
Chromosome DNA Code:
Genes =
Segments of DNA

Code for a trait
DNA Chromosome Code:
Triplets=
Sets of 3 Nucleotides
Code for
Trait
DNA Chromosome Code:
DNA Replication
Chromosomes double
Mitosis
Late Interphase
2n to 4n
E. Steps for DNA Replication:



DNA untwists
DNA unzips
Corresponding base pairs
Line up

In sets of 3
nucleotides (triplets) aka “codons”



DNA reforms
2 strands twist into double helix
RNA Ribonucleic Acid
“DNA messenger & taxi”
II. RNA Structure & Function
A. What is RNA?



Organic Molecule
Nucleic Acid
mRNA = messenger RNA
tRNA = transfer RNA
B. Where is RNA located?
 mRNA in nucleus & cytoplasm
 tRNA only in cytoplasm
B. What is RNA’s structure?
 Acid
 Sugar-Base
 Acid
 Sugar-Base
 Acid
 Sugar-Base
 Acid
 Sugar-Base
 Nucleotides=
a. Phosphoric Acid
b. Ribose sugar
c. Nitrogenous
Bases:
Adenine-Uracil
Guanine-Cytocine
2. Single Strand
3. No Twisted helix
RNA Structure vs. DNA Structure
Comparison of RNA & DNA:
 Acid
 Sugar-Base
 Acid
 Sugar-Base
 Acid
 Sugar-Base
 Acid
 Sugar-Base
D. What are RNA’s functions:




mRNA=
Copies the DNA code
Deliveries message to Ribosome
Protein Factories
Why not send the original DNA code out?
 DNA might be damaged!
 mRNA components are reused
 To copy more messages
RNA function cont.




tRNA:
in cytoplasm
Picks up an amino acid
“Taxis” the aa to the Ribosome protein factories
III. Protein Synthesis
Assembling Proteins from the DNA Instructions. Proteins are chains of amino
acids folded up.
A. Transcription:






mRNA is copied off of DNA
In nucleus
Steps:
DNA untwists
DNA unzips
RNA codons line up
Transcription:
mRNA has:
 Ribose sugar
 Uracil instead of thymine bases
 Nuclear membrane allows it to leave!
B. Translation =
 Conversion of the message (mRNA Code) into a protein
 By the ribosome factories
 Codon – 3 bases on the mRNA that code for an amino acid.
 Anticodon – 3 bases on the tRNA that code for an amino acid – follow base
pairing rules for the codon.
Translation Steps




mRNA arrives at the Ribosome
tRNA picks up an amino acid
tRNA delivers the aa to the ribosome
aa are assembled into polypeptide proteins
Translation
Breaking the Genetic Code (See Genetic Code Handout)
 Scientists can use two tables that reference the genetic code.
 We can read the codons in a strand of mRNA and use the charts to tell us
what amino acids will be added to the polypeptide chain.
Summary:
DNA Replication:
 Make duplicate DNA
 In nucleus
 Copy the chromosomes
 For Mitosis
Protein Synthesis:




Transcrition:
Make mRNA From DNA
Translation:
Make protein - Off mRNA code - Using amino acids