Do Now: - South Orange

download report

Transcript Do Now: - South Orange

Do Now:
•Define genotype and phenotype.
Then determine the relationship
between the two.
THINK
• Where is DNA found?
• What organelle makes proteins? Where is
it found?
• How will the necessary information to
make proteins get from the nucleus to the
ribosome?
Ribonucleic Acid
•
•
•
•
Ribose (sugar)
Single stranded
Uracil replaces Thymine
3 types : messenger, transfer and
ribosomal RNA
– mRNA, tRNA, rRNA
Transcription
• Promoter sequences signal RNA polymerase
to bind to DNA at specific sites & separate the
DNA strands
• RNA polymerase uses template as “sense”
strand to form mRNA by building complimentary
nucleotides
• Re: RNA uses Uracil in place of Thymine
Example: DNA code: T T A G C C
mRNA: A A U C G G
• mRNA is edited (introns cut out, exons
spliced together)
• Edited mRNA goes to ribosome (site of
protein synthesis)
THINK
• IF we refer to DNA&RNA as a nucleotide
“language” (codes in base sequence)
• ..and proteins as amino acid language (aa
sequence = proteins)…
• Quelle est la prochaine étape?
• (What is the next step?)
• TRANSLATION
Translation
• Cell uses information from mRNA to
produce proteins
• tRNA will be our “translator”
• mRNA “words” are read in 3 nucleotide
sequences known as codons
• tRNA has only one specific aa for every
complimentary mRNA codon, known as an
anticodon
• Re: Proteins (polymer) are made from chains of amino acids
(monomer) joined by peptide bonds. AKA polypeptide
• Protein shape is determined by sequence of any combination of the
20 aa
• (4X4X4)64 possible 3-base codons
Genetic Code
Protein Synthesis (summary)
1.
2.
3.
4.
mRNA is transcribed
Ribosome positions start codon to bind to anti-codon
on tRNA
Ribosome moves along mRNA, binding new tRNA
and aa’s. Peptide bond binds aa’s as the chain builds
and tRNA’s move along the chain
Process continues until there is a stop codon in mRNA
http://www.lewport.wnyric.org/jwanamaker/animations/Prot
ein%20Synthesis.html
http://learn.genetics.utah.edu/units/basics/transcribe/
DO NOW
1. NAME 3 DIFFERENCES BETWEEN
DNA AND RNA.
• EXTRA CREDIT
• Create a free
standing 3D model
of a DNA molecule
• Must be accurate
in representing all
parts, including all
bonds.
• DUE MONDAY
• HOMEWORK
• p.read p299 mini lab
• “how DNA controls
the cell”