Download - RNA & Transcription
11-18-08
DNA Review Contains the genetic instructions used
in the development and functioning of all organisms
Found in the nucleus of cells! Made up of Nucleotides
Sugar (deoxyribose)Phosphate Nitrogenous Base
Adenine Thymine Cytosine Guanine
DNA Replication 1 DNA strand 2 DNA strands The first DNA strand acts as a template
for the newly formed strand of DNA DNA polymerase copies the new strand
of DNA
Practice replicating DNA!!!
Single stranded Sugar is Ribose
DNA = Deoxyribose Copied from DNA during a
process called transcription Made up of nucleotides Does not contain thymine
Uracil (U) replaces thymine in RNA strand
DNA vs. RNA DNA ATT GAT CAT AGT
RNA AUU GAU CAU AGU
mRNA- (messenger RNA) sends the message of DNA to the ribosomes
rRNA- (ribosomal RNA) make up ribosomes (place of protein assembly)
tRNA- (transfer RNA) transfers the RNA message into proteins
Makes RNA from DNA
DNA- GCA CTA GTC ATCRNA- CGU GAU CAG UAG
End Result: 1 DNA strand 1 mRNA
Strand
Transcription Steps 1. RNA polymerase, an enzyme, binds to
DNA found in the nucleus and separates the DNA strands
2. RNA polymerase then uses one strand of DNA as a template for assembling a strand of mRNA that is then released into the cytoplasm.
REVIEW DNA Replication
1 DNA Strand 2 DNA Strands Transcription
DNA RNA Translation
RNA Protein
Making Proteins The sequence of nucleotides serves as
instructions for the order of amino acids Proteins are made from joining many
amino acids into a long chain The code is read 3 letters at a time
Codon Every three
nucleotides is a word known as a codon. AGTTCCGAT AGT TCC GAT
Each specific codon represents a single amino acid Chains of amino
acide make proteins 64 different codons
Translation Decoding of a mRNA into a polypeptide
chain or protein.First mRNA is transcribed from DNA and
released to the cytoplasm
5 Basic Steps in Translation Step 1: A ribosome forms around a
molecule of mRNAneeds the start codon AUG
Step 2: Each codon allows the proper amino acid to be brought into the ribosome by tRNA.
Step 3: The amino acids are attached together along an “assembly line” to form a chain.
Step 4: The new protein grows as the codons are 'read‘ until a stop codon appears
Step 5: The completed protein is released.
Codons and Translation Start codon- "AUG" - Methionine
signals initiation translation Stop Codon- "UAG, UAA, and UGA"
signals termination of translation
Let’s practice decoding Codons! UUUCAGGAA
AUACCGAGA
GCUGACUAC