Download Unit 6 Protein Synthesis

Bell Ringer-Definitions PG 86
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 VI – Protein Synthesis
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 87
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 87
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 87
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
87
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
Elbow Partner Work 5 mins
Page 91: 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 87
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 87
tRNA carries a code of 3 letters called an anticodon
that pairs up with the codons of mRNA
Make a tRNA row under 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 87
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
HOW did I get the AA’s? We look at the mRNA
codon for the code. These are what the tRNA will
pick up
PG 89 Use a chart to find order of AA’s:
Which AA is:
CGU
Arg
AUC
Iso
PG 89Use a chart to find order of AA’s:
Which AA is:
UCA
Ser
GAG
Glu
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.
Practice Makes Perfect PG 89
Work on your DNA sequencing (INDIVIDUALLY) when you are
finished, raise your hand so I can come check your work 8
Minutes!
We will go over it so there is no confusion!
If you finish early, go to page 93! Read the information and start
working on the worksheet! If you do not finish, this is
homework!!!!!
Page 89
DNA Strand 2:
ATG-GGA-TTC-CGT-GCC-ATT-TAA
mRNA STRAND (Codon Sequence):
AUG-GGA-UUC-CGU-GCC-AUU-UAA
ANTICODON SEQUENCE (tRNA):
UCA-CCU-AAG-GCA-CGG-UAA-AUU
PROTEIN SEQUENCE (Amino Acid):
MET-GLY-PHE-ARG-ALA-ISO-STOP
Bell Ringer- Definitions PG 86
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
Protein Synthesis PG 88
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 88
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 90
Name the process:
Transcription
Translation
Protein Synthesis PG90
Name the parts:
DNA
mRNA
tRNA
Amino Acid
Protein
Ribosome
Protein Synthesis PG 88 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
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
https://www.youtube.com/watch?v=itsb2SqR-R0
Bell Ringer-do this on page 86
or 89
For each DNA strand give the mRNA,
tRNA, & AA
DNA: TACACCTTGGCGACGACT
DNA: TACACCTTGGCGACTACT
DNA: TACACCTTGGGACGAACT
DNA: TACGACCTTGGCGACGACACT
Intro to Gene Mutations
https://www.youtube.com/watch?v=GieZ3pk9YVo
Gene Mutations PG 95
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 95
May occur in
reproductive cells
(gametic cells)
Affects offspring, not
you
…Or in “body
cells”(somatic cells)
Affects you, not
offspring
Gene Mutations PG 95
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 95
Point Mutations
Point Mutation Exp
Gene Mutations PG 95
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 PG 95
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
BELL RINGER- INDIVIDUAL
WORK
Work on page 93-get a stamp when you are
finished
When you are finished work on page 92
(practicing mRNA) write down the mRNA
sequence & the protein sequence (amino
acid) – get a stamp
Work on page 94 this is a grade!
Add this question to your review: (next
slide)
Add this question to your
review
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