Download Jan. 28 Bio II Answer to warm up Protein Synthesis

HW: read p. 307-308; do #1-4 p. 308
Answer to warm up
Jan. 28
Bio II
Using RNA to make proteins allows
protein synthesis to speed up
Question: Name two
advantages of copying DNA’s
message instead of using
DNA directly to make proteins
DNA can make multiple copies of RNA
and each copy of RNA can be used to
make proteins.
DNA remains in the nuclei of
eukaryotic cells where it is protected.
Extra credit project – Due Feb. 3
Three dimensional model of DNA using beads,
pipe cleaners, wire, gum drops, or other
materials
Model needs to be sturdy but creative,
accurate, and visual interesting
Provide a key that explains the parts of the
model
Grade is based on accuracy and aesthetic
appeal
NO LATE PROJECTS ACCEPTED!
Protein Synthesis
DNA contains all of the genes that code for
the proteins that we need to survive.
DNA does not however make proteins
directly.
DNA is used to make RNA inside of the
nucleus. Then the RNA exits the nucleus
where it can be used to make proteins in
the cytoplasm.
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Protein Synthesis (transcription)
RNA is made
from a template
strand of DNA.
The DNA holds
the code but the
code cannot be
expressed unless
it is transcribed
into RNA
Codon
The flow of information
From gene to protein is
Based on a triplet code;
Bases are “read” in 3’s
Called codons
Review of protein structure
Proteins are a chain
Of amino acids joined
Together by peptide bonds
DNA determines the
order of the amino acids
in the chain (polymer)
Here are the 20
amino acids that
are used to build
a polypeptide chain.
A polypeptide chain
is the primary stage
of a protein
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tRNA
tRNA carries an
Amino acid to the
Ribosome where it
Can bond with a
Specific codon from
mRNA
Protein synthesis
Protein Synthesis (translation)
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mRNA enters the cytoplasm outside the nucleus
Ribosome(s) attach to the mRNA at the start
codon
The ribosome has three active sites of three
codons each
When a tRNA bumps into the ribosome that has
the complimentary sequence to a codon, the tRNA
is trapped and fit into place.
The bond between the tRNA and the amino is
broken and the amino acid is now held by the
ribosome.
As additional tRNA’s get trapped, each new
amino acid is added to the chain
Activity 8 (Insulin Gene)
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4.
Read the introduction, Part A, and Part B
Complete the Practice sheet for finding the
DNA sequence for the 3 amino acids given;
use the genetic wheel
Look at the Bovine insulin protein chain on p. 9
in packet; teacher will assign you 3 amino
acids; write them down on your worksheet;
complete the worksheet
Lay out your base models in the order you
determined on your worksheet
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