Download DNA RNA PSyn notes

DNA/RNA/Protein Synthesis
I.
Scientists
a. Griffith: pneumonia bacterium, transformation
b. Avery-McCarty-MacLeod: replicated Griffith, determined it was the DNA
c. Hershey-Chase: radioactivity and bacteriophages
d. Watson-Crick: structure of the DNA, double-helix
II.
Structure of DNA (Deoxyribo-nucleic acid)
A. Characteristics and general information- Watson and Crick
1- DNA is the genetic information molecule of life
2- DNA the common molecular thread, which connects all living things together
3- DNA ultimately controls the manufacture of all proteins (template)
4- DNA is an effective information storage molecule
5- DNA consists of a double helix
6- DNA is self-replicating
B. Chemical makeup (basic building blocks: nucleotides)
1- Five carbon sugar ---> deoxyribose
2- Phosphate group
3- Nitrogen base (four different bases: ATG and C)
4- A and T match up together (complimentary), G and C match up together
C. Functions of DNA
1- Stores genetic information
2- Controls protein synthesis (serves as master blueprint for manufacturing all proteins)
3- Self-replicating
Replication: copy DNA
Transcription: make an RNA copy
Translation: read code of RNA at the ribosome
Genetic codons and amino acids (see pg 149)
III.
RNA (Ribonucleic acid)
A. Characteristics and general information
1- RNA is directly involved in protein synthesis
2- All RNA is transcribed from DNA
3- RNA is a molecule consisting of a single helix
B. Chemical makeup (basic building blocks: nucleotides)
1- Five carbon sugar (different from DNA)---> ribose
2- Phosphate group
3- Nitrogen base (four different bases: AUG and C; one is different from DNA)
C. Types and function of RNA
1- Messenger RNA (mRNA) is the working blueprint for properly arranging
amino acids during protein synthesis, each specific protein is made from a
different mRNA. mRNA contains the codon (three letter sequence code)
One codon codes for only one amino acid.
2- Transfer RNA (tRNA) transports amino acids to site of protein synthesis and
then “reads” the mRNA blueprint in order to properly position each amino
acid in the protein molecule. TRNA has the anti-codon to mRNA.
3- Ribosomal RNA (rRNA) is the structural part of the ribosome, assists in the
lining up of tRNA and mRNA. The ribosome is made up of rRNA
III.
Comparing DNA and RNA
A. DNA
1- Sugar= deoxyribose
2- Nitrogen bases
a. Adenine
b. Guanine
c. Cytosine
d. Thymine
3- Double stranded molecule
B. RNA
1- Sugar= ribose
2- Nitrogen bases
a. Adenine
b. Guanine
c. Cytosine
d. Uracil
3- Single stranded molecule
IV.
Protein Synthesis
The process whereby amino acids are linked together into a chain
(polypeptide) by means of condensation reactions to form a protein.
DNA ultimately dictates the sequence of amino acids in each protein.
A. Step 1: transcription of DNA to form mRNA (in nucleus, eukaryotes)
B. Step 2: translation of mRNA and tRNA with amino acid attached-->
amino acid bonded together (peptide bond) takes place at the ribosome (rRNA)
C. Factors affecting protein synthesis
1- Environmental factors ( temp, pH, toxins)
2- Materials and energy
rRNA
(DON’T DRAW THIS)
codons
Vocabulary:
anticodon:
codon:
complimentary:
DNA:
mRNA:
nitrogen base:
nucleotide:
replication:
rRNA:
peptide bond:
template:
transcription:
translation:
tRNA:
Study Questions:
1. Distinguish between RNA and DNA in as many ways as you possibly can.
2. Draw a nucleotide and then draw a 5 nucleotide linear sequence of DNA.
3. Distinguish between mRNA, tRNA and rRNA in protein synthesis.
4. Given the following nitrogen base sequence in a molecule of DNA:
AATCGTTCGTTAGCGCCA (this is obviously only one side of the DNA molecule)
answer the following:
a. what would the other side of the DNA strand look like?
b. what would a transcribed mRNA strand look like?
c. how many amino acids would be in the protein coded by the sequence
d. what would be the codon (from left to right) for the second amino
acid in the protein chain?
5. Distinguish between transcription, translation and replication. Diagram and label all
three of these processes beginning with the segment of DNA listed in question four.
Functions of DNA
replication
DNA
transcription
RNA
translation
protein
Nucleotide
Phosphate Group
P
O
nitrogenous base
sugar
HO
DNA Chain (one side)
P
P
sugar
P
P
P
P
sugar
sugar
sugar
A
T
T
G
C
G
T
A
A
C
G
C
covalent bonds
sugar
P
sugar