Protein Synthesis
1. Humans share most of the same protein families with ___________, flies, and
plants
2. Hair grows by forming new cells at the base of the root. As they move upward
through the skin they are cut off from their nutrient supply and start to form a hard
protein called _______________ in a process called keratinization. As this
occurs, the hair cells die. The dead cells and keratin form the shaft of the hair.
3. Fingernails grow about _______________ times as quickly as toenails
4. Each hair grows about __________/month and grows for up to ____ years.
5. The most expressive muscles are the facial muscles. We need ______ muscles
to smile and ______ muscles to frown.
6. The most numerous are the skeletal muscles. When we walk for instance, we
use _____ muscles.
It is expected that students will be able to …
1. Demonstrate knowledge of the basic steps of protein synthesis, and identify the
roles of DNA, mRNA, and ribosomes in the processes of transcription and
translation. (p. 481-486)
2. Use the table of mRNA codons to determine the sequence of amino acids coded
for by a specific DNA sequence (p. 481)
3. Give examples of 2 environmental mutagens that can cause mutations in
humans. (p. 490)
4. Use examples to explain how mutations in DNA affect protein synthesis and may
lead to genetic disorders (p. 490)
VOCABULARY
_____ Adenine
_____ Anti-codons
_____ Central Dogma
_____ Code
_____ Codon
_____ Complementary Base
_____ Cytosine
_____ Elongation
_____ Endoplasmic
reticulum
_____ Exocytosis
_____ Gene
_____ Gene mutation
_____ Genetic code
_____ Golgi body/Apparatus
_____ Guanine
_____ Helicase
_____ Histones
_____ Hydrolytic enzymes
_____ Initiation
_____ Initiation codon
_____ Messenger RNA
(mRNA)
_____ Mutagen
_____ Mutation
_____ Peptide bonds
_____ Peptidyl Transferase
_____ Point mutation
_____ Polypeptide
_____ Polysome
_____ Protein
_____ Protein synthesis
_____ Ribosomes
_____ RNA Polymerase
_____ Template
_____ Terminator codon
_____ Thymine
_____ Transcription
_____ Transfer RNA (tRNA)
_____ Translation
_____ Triplets
_____ Uracil
_____ Vesicle
Proteins Have 2 Main Functions
1. Structural: proteins help make up all structures in living things
Examples: a) ___________________
b) ___________________
c) ___________________
2. Functional: other proteins help us to keep our bodies functioning properly and
to digest our food.
Examples: a) ___________________
b) ___________________
c) ___________________
d) ___________________
Protein structure is determined by the genetic code in your
DNA. The section of DNA that codes for one protein is
called a _______________.
A gene is a section of DNA that determines the
____________________________ in a protein.
Therefore, the _____________________________ and
therefore, the _______________ of the protein it codes
for.
Central Dogma of Biology
One _________ codes for one type of ____________ which does one ____________
in the cell.
How Does Protein Synthesis Work?
If the process of protein synthesis were a
play, these would be the roles of all of the
people involved
The director who has the master plan
=______________
The 3 assistant directors? _______, _______,
_______
The cast (actors) = _________________
The stage = _________________
The stage crew (helpers) = ________________
Act One: ________________ (Trans = across, cription = to write)
The coded message of a gene on DNA has ____________________
on how to make _________ particular ________________ that our
bodies need.
The instructions from a gene are copied from DNA to
________________ (__________) in the nucleus.
Then, the mRNA moves through the _____________________ and
into the cytoplasm where the proteins are made.
The process of making mRNA is called ______________________
Watch the General Process
Step 1: ________________ the DNA (starting at the promoter).
Step 2: ______________________________ attach to form the mRNA strand
Step 3: _______________ forms the RNA ______________ _______________ and
checks for __________________
Step 4: The __________________ & leaves the nucleus, & the __________________
Act Two: __________________________
The mRNA code is made up of groups of _____________ ________ known as
_________. Each codon codes for a specific ________________.
Eg. AGC = Serine
Eg. UGC = Cysteine
CAU? ____________
GCC? ____________
See text figure 25.7 (page 481)
CUU? ____________
UGA? ____________
AUG? ____________
AAA? ____________
Why a Triplet Code?
It takes ____ nucleotides on the mRNA to code for _____.
Why? We must code for ______ different amino acids and there are only
__________ (nucleotides) in the alphabet.
With a _____ nucleotide, there are only __ possible codes (41).
For _____ nucleotides, there are only __ possible codes (42).
However, for ______ nucleotides there are ____ possible codes (43), and
that is enough to code for the 20 amino acids.
Translation
•
The written code (codons) on mRNA is
‘_____________’ into a specific amino acid
sequence by _____________ in the
cytoplasm.
•
This is carried out with the help of relatively
small _____________ _______ molecules.
A tRNA molecule is a small piece of RNA that
has a _________________________ attached
to it.
The tRNA also has a special sequence of 3
nucleotide bases known as an ____________.
There is at least one type of tRNA for each of the
20 amino acids.
As the correct _____________ are brought to the ribosome by the _________,
they are joined together via __________________ to form the ___________ that
the original DNA coded for.
Please note that there is ______________________ for each amino acid:
mRNA codons:
tRNA anti-codons:
U C U
______
G C C
______
The Steps of Translation:
1. The mRNA molecule moves ____________________ in the nuclear
envelope and in to the cytoplasm. It joins with a ___________ and is
translated one amino acid at a time.
2. ‘______________’: the first codon on any mRNA molecule is called the
‘____________’ codon. This codon is always ________, which codes for
the amino acid _________. This is a message to ________ translation.
3. ‘_______________’: the ribosome’s job is to position the tRNA molecule
onto the matching mRNA molecule.
4. ________________: The last codon on any mRNA molecule is called the
___________________, which is a message to ____________ translation.
________________: The last codon on any mRNA molecule is called the
___________________, which is a message to ____________ translation.
CRACKING THE GENETIC CODE
A BAD NIGHT AT THE THEATRE
Question: What if something goes wrong during translation?
Answer: ___________________
•
•
•
A ____________ in the nucleotide
sequence of DNA
When the ________ (‘letters’) change, the _______________ are used to
make the protein.
The protein will _______ ______ to do its _____.
There are 2 types of MUTATION:
1. ______________ mutations: a mutation of all or part of a chromosome.
This usually involves ______________, and therefore,
________________.
Example: Down’s syndrome.
2. _________ mutations: a mutation that occurs within a gene at some
point along a chromosome. This mutation is only a change of 1 or a few
‘letters’ (nitrogenous bases).
It usually only affects ___________, and therefore, _____________.
Example: Sickle cell anemia.