Bell Ringer-Definitions PG 94
Transcription- to copy
Codon- sequence of 3 DNA or RNA nucleotides
Anticodon- region of tRNA that is a sequence of 3 bases
that are complementary to a codon in the mRNA
mRNA- messenger RNA; copies directions from DNA
takes them to ribosomes
tRNA- transfer RNA; picks up certain AA & brings them to
the ribosome for assembly
Translation- DNA protein
Mutation- changes in DNA codes (harmful, helpful, no
effect)
Gene mutation- reproductive cells, body cells, point
(single base), frame shift (inserted or deleted)
Unit IV – Cell Function PG 94
Part 3 – Protein Synthesis
The Story of the Ribosome
Target
REVIEW: Describe the structure of the DNA molecule
REVIEW: Distinguish between genes and
chromosomes
Explain how DNA codes for proteins and how these
proteins lead to traits
Compare and contrast DNA and RNA
Describe the specific roles of mRNA and tRNA in the
making of a protein
How do we get actual traits from DNA? Pg 95
AMOEBA SISTERS- Page 100
Our heritable traits are determined by the proteins
that we make (including our enzymes)
Example: a gene in DNA has directions for how to
build melanin…melanin gives you your skin
coloration
gene

protein

trait
Rules for Building a Protein PG 95
1) DNA cannot leave the nucleus
2) Must have a messenger to get code from DNA
& take it to ribosome (mRNA)
3) Proteins are made from amino acids (AA’s)
(tRNA)
Both DNA & RNA are needed to
build a protein PG 95
Although they are similar there are some important
differences:
DNA
2 strands
Deoxyribose sugar
Thymine (T) binds with A
RNA
1 strand
Ribose sugar
Uracil (U) binds with A
RNA
How does RNA
differ from
DNA?
1 strand
U not T
ribose
What types of RNA are there? PG
95
mRNA (messenger RNA) - copies the directions
from DNA & takes them to the ribosomes
(TRANSCRIPTION)
tRNA (transfer RNA) - picks up certain AA’s &
brings them to the ribosome for assembly
(TRANSLATION)
DNA Triplets- called codons
RECAP
DNA
RNA
Double stranded
Single stranded
Deoxyribose sugar
Ribose sugar
Thymine (T) pairs with Adenine
Uracil (U) pairs with Adenine
Cannot leave nucleus
Must have a messenger to get code
from DNA and take to Ribosome
https://www.youtube.com/watch?
v=z2oxK0wfyXY
https://www.youtube.com/watch?
v=gB4QHaOeKz8
Bell Ringer
Page 99: Comparison of RNA & DNA
Without using your notes try to answer the blanks given
to you. Once you are finished, you may use your notes
to check your answers!
Make sure to study this for your quiz on FRIDAY
Construction workers
We will go over this together.
You can try to fill it out first though (in pencil)
How does mRNA know how to
copy DNA? PG 95
DNA triplets match up with sets of 3 mRNA
bases…called codons (write this under or
above squiggly line)
If DNA says this…what will mRNA be?
TAC – GGA – CTT – GAT – ACA – ATT
AUG – CCU – GAA – CUA – UGU – UAA
How does mRNA know which
AA’s to assemble? PG 95
tRNA carries a code of 3 letters called an anticodon
that pairs up with the codons of mRNA
If mRNA says this…what will the tRNA’s be?
AUG – CCU – GAA – CUA – UGU – UAA
UAC – GGA – CUU – GAU – ACA - AUU
How does mRNA know which
AA’s to assemble? PG 95
Each tRNA can only pick up one specific AA
When it matches up with the codon, it brings along its
AA
rRNA- ribosomal RNA, essential for protein synthesis
in ALL living organisms (write this somewhere on your
page!)
If tRNA says this…what will the AA’s be?
UAC – GGA – CUU – GAU – ACA – AUU
Met – Pro – Glu – Leu – Cys - Stop
Make a tRNA row under mRNA
PG 97 Use a chart to find order of AA’s:
Which AA is:
CGU
Arg
AUC
Iso
PG 97Use a chart to find order of AA’s:
Which AA is:
UCA
Tyr
GAG
Glu
Practice Makes Perfect PG 97
Work on your DNA sequencing (individually) when
you are finished, raise your hand so I can come check
your work 10-15 Minutes!
We will go over it so there is no confusion!
If you finish early, go to page 101! Read the
information and start working on the worksheet!
RECAP
DNA
RNA
Double stranded
Single stranded
Deoxyribose sugar
Ribose sugar
Thymine (T) pairs with Adenine
Uracil (U) pairs with Adenine
Cannot leave nucleus
mRNA- convey genetic
information from DNA to the
ribosome
Must have a messenger to get code
from DNA and take to Ribosome
tRNA- helps decode a mRNA
sequence into a protein
rRNA- essential for protein
synthesis in all living organisms.
Bell Ringer- Definitions PG 94
Polypeptide- chains of AA’s, proteins are made up of one or more of
this!
Ribosome- an organelle responsible for production of protein in all
living things
Protein- macromolecules, consisting of one or more long chains of AA
residues
Triplet- group of 3 bases, codes for a specific AA
Amino Acid- organic compound with Amine & Carboxylic acid
functional groups, usually along with a side-chain specific to each AA
Note book check- page 101
Protein Synthesis PG 96
Transcription (“to copy”)
mRNA goes to nucleus & copies DNA code
for one gene
mRNA takes the copy to the ribosome in the
cytoplasm
Protein Synthesis PG 96
Translation (“DNA” to
“protein”)
Ribosome uses mRNA
copy to look for certain
tRNA’s (ones with correct
anticodon)
tRNA’s pick up specific
AA’s & bring them to
ribosome when they are
needed
AA’s are pulled off tRNA’s
& attached to the growing
protein chain
Protein Synthesis PG 98
Name the process:
Transcription
Translation
Protein Synthesis PG98
Name the parts:
DNA
mRNA
tRNA
Amino Acid
Protein
Ribosome
Amoeba Sisters (part 2)
https://www.youtube.com/watch?v=D3fOXt4MrOM
https://www.youtube.com/watch?v=2zAGAmTkZNY
https://www.youtube.com/watch?v=h5mJbP23Buo
Finish the back side of page 100 (Amoeba sisters)
This is a grade, raise hand when you are finished
RECAP
Transcription- means to copy
mRNA  nucleus  copies DNA code for one gene
Translation- makes DNA into protein
Ribosomes use mRNA copy to look for certain AA’s and RNA’s
tRNA pick up specific AA take them to ribosome when needed
AA’s pulled off tRNA  attach to growing protein chain
BELL RINGER PG 101
Study for 10 Minutes, ask me questions if you need
help
Intro to Gene Mutations
https://www.youtube.com/watch?v=qVmusHZtQms
Protein Synthesis PG 96 write this on
the page on the sides (or near name)
Changes in DNA code may be harmful, helpful, or have no effect
If instructions for cell division are affected, this can lead to cancer!
Point Mutation
A change in a single DNA base may or may not affect the AA sequence
Frameshift Mutation (have the greatest affect!)
Codons shift when a single base is inserted or deleted, this changes the
AA sequence
Gene Mutations PG 103
Sometimes mutation (errors) occur
Changes in DNA code may be harmful,
helpful, or have no effect
EXP= If instructions for cell division is
affected, can lead to cancer (uncontrolled cell
growth)
Cancer
Gene Mutations PG 103
May occur in
reproductive cells
(gametic cells)
Affects offspring, not
you
…Or in “body
cells”(somatic cells)
Affects you, not
offspring
Gene Mutations PG 103
Point Mutations
A change in a single DNA base
THE DOG BIT THE CAT
THE DOG BIT THE CAR
This may or may not change the protein that is
made (some AA’s have more than one code)
Gene Mutations PG 103
Point Mutations
Point Mutation Exp
Gene Mutations PG 103
Frameshift Mutations
AA’s shift when a single base is inserted or
deleted
THE DOG BIT THE CAT
THE DOB ITT HEC AT
(deletion)
THE DOQ GBI TTH ECA
(insertion)
Gene Mutations PG103
Frameshift Mutations
Uner Tan Syndrome
Progeria
Mutations
Hypertrichosis
Epidermodysplasia verruciformis
Polycystic Kidney Disease
Sickle Cell Disease
RECAP
Gene mutations
Changes in the DNA sequence
Point mutations
Single base change in AA sequence
Frameshift mutations (have the greatest affect)
Inserted base in AA sequence
Deleted base in AA sequence
Group Activity
Work on page 102
This is a grade!
Use your codon chart on page 97
When you are done raise your hand so I can
check your work!
BELL RINGER- INDIVIDUAL
WORK
Work on page 97 (DNA Sequencing)
When you are finished work on page 104
(practicing mRNA) write down the mRNA
sequence & the protein sequence
Get out your study guide and start working
on that, add the questions on my white
board to your study guide and answer them
as well!
Page 97
DNA Strand 2:
ATG-GGA-TTC-CGT-GCC-ATT-TAA
mRNA STRAND:
AUG-GGA-UUC-CGU-GCC-AUU-UAA
ANTICODON SEQUENCE:
UCA-CCU-AAG-GCA-CGG-UAA-AUU
PROTEIN SEQUENCE:
MET-GLY-PHE-ARG-ALA-ISO-STOP
Pre Test Questions
Which mutation would change the greatest number of
AA’s in a protein?
The deletion of a single Adenine nucleotide in the middle of a
gene
The substitution of a Thymine nucleotide with a Cytosine
nucleotide near the beginning of a gene
The addition of the nucleotides that make up an additional stop
codon to the end of a gene
The insertion of 3 bases, such as a Thymine, a Guanine, and an
Adenine nucleotide in that order at the start of a gene