02/04/15
• To Do:
1.
2.
3.
4.
Bell Work
DNA to Proteins
Code Project
Complete Coded
Message
• Bell Work:
• Copy To Do in Agenda.
• Pick up your SIN
• On pg. 67, create a
diagram showing how
DNA is copied.
• Label the parts of the
diagram.
• Remember to use your
notes and worksheets
to help you!
Announcements
• Procedure Changes:
• No more test corrections, but retakes will be available.
• Students who have a C- or below will receive after school
detention on Thursdays to provide time for improvement
(assignment corrections, test retakes, complete missing work,
etc.).
• You, your parents, and the administration will be notified.
• No Late Work without Mac Pass!
• You have 4 for the semester, use them!
• Complete them well, or you don’t get full credit.
• May not use the last two weeks of the quarter.
The DNA Connection
•
•
Notes on pg. 70 of SIN.
How do we go from DNA to
who we are?
•
•
•
DNA codes for proteins.
Proteins are what make us
different.
Think about blood type.
Hot Pockets and DNA to Proteins
• What is a hot pocket?
• As we watch, take notes on the video.
• Notes are on how DNA codes for proteins.
The DNA Connection
•
What are the steps for
going from DNA to
protein?
1. DNA is copied into RNA
– What is the difference
between RNA & DNA?
– DNA has a T where RNA
has a U
2. RNA is then transcribed
into protein.
– Each three bases code
for an amino acid.
– These three bases are
called a codon.
– A change in the code will
cause a mutation in the
protein made.
Differences between RNA and DNA
• RNA
• Ribose sugar
• Single-stranded
• Contains uracil instead
of thymine
• Make proteins
DNA
Deoxyribose sugar
Double stranded
Contains thymine
Directs cell activities
Types of RNA
1. Messenger RNA: carry instructions for how to
assemble amino acids into proteins
2. Ribosomal RNA: help make ribosomes
3. Transfer RNA: transfers each amino acid to the
ribosome
Types of RNA
Transcription
• RNA is made by copying part of a nucleotide sequence of DNA
• RNA polymerase binds to DNA and separates the strands and
uses one strand to make a new strand of RNA
• Promoters: RNA polymerase will only bind to the regions of
the DNA strand known as promoters
RNA Editing
• Introns: sequences of DNA nucleotides that are not involved in
coding for proteins
• Exons: DNA sequences that code for proteins
• RNA is edited by cutting out the introns and splicing the exons
together
The Genetic Code
• There are 20 amino acids
• Proteins are made by joining amino acids in chains called
polypeptides
• Codon: consists of three consecutive nucleotides that specify
a single amino acid.
Translation
• Takes place in the ribosomes
• The cell uses the information
from messenger RNA to produce
proteins
Steps of Translation
• 1. mRNA is transcribed from DNA in the nucleus and released
into the cytoplasm
• 2. An mRNA molecule attaches to a ribosome. As each codon
of the mRNA molecule moves through the ribosome, tRNA
brings the proper amino acid into the ribosome to add to the
polypeptide chain
Steps of translation continued
3.
4.
The ribosome forms a peptide bond between the first and
second amino acids
The polypeptide chain grows until the ribosome meets a
stop codon
The Roles of RNA and DNA
• DNA stays in
the nucleus
• DNA makes
RNA
• RNA travels to
the ribosomes
• RNA makes
proteins
Genes and Proteins
• Most genes contain instructions for assembling proteins
• Many proteins are enzymes that control chemical reactions
• Proteins are specifically designed to build or operate a
component of the living cell
Review
DNA to Protein Review
• Complete Review WSs and tape to pg. 69 of your SIN.
The DNA Connection
• Creating your own code
based on the genetic code
and write a letter in it:
1.
2.
3.
4.
Assign each codon to a
letter, type of punctuation,
and anything else you
need for writing a letter.
You will need to include
codes for spaces and the
end of sentences.
It should have perfect
grammar.
You will have three things
when you are finished:
a.
b.
c.
A letter written
completely in code.
A decipher sheet for
decoding your letter.
The original letter before
it was coded.