Transcript Chapter 10 Protein Synthesis

Chapter 10 - Protein Synthesis
http://www.oconee.k12.sc.us/webpages/tstanton/imageGallery/Protein%20Synthesis%20Diagram.jpg
Chapter 10 Vocabulary List
1.
2.
3.
4.
5.
6.
7.
8.
9.
Anticodon
Codon
Gene expression
Genetic code
Messenger RNA
Point mutation
Intron
Exon
promoter
10. Ribonucleic acid (RNA)
11. Ribosomal RNA
12. Transcription
13. Transfer RNA
14. Translation
15. Polypeptide
16. Frameshift mutation
17. Mutagen
Don’t lose your DNA!!
Proteins are Made by Decoding the
Information Stored in DNA
A. Transcription
1. Copying DNA into RNA
B. Translation
1. Converting message from nucleic acid to amino acid
C. Transcription
+
Translation
=
Gene Expression
RNA – Ribonucleic Acid
A. Single-Stranded
1. DNA is double-stranded
B. 5-Carbon sugar – ribose
1. DNA uses Deoxyribose
C. Thymine is replaced by Uracil
D. 3 types of RNA:
1. messenger RNA (mRNA)
2. transfer RNA (tRNA)
3. ribosomal RNA (rRNA)
http://www.biologycorner.com/resources/mRNA-colored.gif
Transcription (TX)
http://www.studydroid.com/imageCards/01/eq/card-1534191-back.jpg
A. The transfer of the
protein blueprint from
DNA into RNA
1. DNA is too large
and valuable to let
out of the nucleus
i. It is the primary
computer code
for the cell
2. RNA is a portable
copy
i. It is like the
copy of a song
for your I-Pod
B. Tx is transcribing or
copying the message
carried on the DNA
C. Tx occurs in the nucleus
Translation (TL)
A. Using the instructions in RNA to put together amino
acids to make protein
B.TL occurs in the cytoplasm on Ribosomes
C. TL is also called Protein Synthesis
Review Questions
1. What is Transcription?
2. What is Translation?
3. What is Gene Expression?
4. How many different types of RNA are there?
5. What are they?
6. How does RNA differ from DNA?
Transcription Transfers Information
from DNA to RNA
A. RNA Polymerase – an enzyme
1. Unwinds DNA and adds
nucleotides to make RNA
2. Promoters- RNA polymerase
only binds to regions of DNA
with specific sequences.
A = adenine
T = thymine
G = guanine
C = cytosine
U = uracil
B. RNA is made following same basepairing rules as for DNA replication
1. Thymine is replaced by Uracil
2. A – U and G – C
http://www.idigitalmotion.com/portfolio.htm
Introns and Exons
A. Genes are made up of coding and noncoding sequence
B. Introns – noncoding
1. DNA that does not code for protein sequence
C. Exons – coding
1. DNA that
encodes
protein
D. After Tx,
Introns are
removed and
Exons are
joined together
The Genetic Code is Written in
3-Nucleotide “Words” on mRNA
A. mRNA
1. Carries instructions from the nucleus to the cytoplasm
2. A portable copy
of the DNA
B. Codons
1. 3-Nucleotide
sequences that
codes for a
single amino
acid
http://image.slidesharecdn.com/rna-protein-synthesis-141203111238-conversion-gate01/95/rnaproteinsynthesis-13-638.jpg?cb=1417605207
The Genetic Code
A. 64 mRNA codons are possible
1. Four nucleotides in 3-letter combinations
2. 43 (4 cubed)
B. There are only 20 amino acids
1. In some cases, several codons code for the same
amino acid
C. Some codons are “start” and “stop” codons
The Genetic Code
Third letter
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/code.gif
Review Questions
7. What enzyme makes RNA?
8. What type of RNA does it make?
9. After Tx, are Introns or Exons removed from
the mRNA?
10. What do you call the 3-Nucleotide sequences
that code for an amino acid?
11. How many codons are there?
Translation – Transfer RNA
A. tRNA
1. Carries amino acids
to the ribosome during
translation
B. Anticodons on tRNA
1. Complementary to the
codons on the mRNA
Translation – Ribosomal RNA
A. rRNA – the third
type of RNA
B. rRNA makes up
much of the structure
of the Ribosomes
C. Ribosomes are the
assembly line in the
factory where
protein “robots” are
made
ttp://www.frontiers-in-genetics.org/page.php?id=protein-synthesis_en
Translation
A. Step I: the ribosome
reads codons on mRNA
B. Step II: the 1st tRNA
brings the 1st amino acid
C. Step III: a tRNA brings
the next amino acid
III
D. Step IV: the two amino
acids are connected and
the empty tRNA leaves
E. Step V: steps III & IV
are repeated until a stop
codon is reached
IV
V
http://biologyteksbylauryncarter.weebly.com/uploads/2/6/6/1/26614318/6182195_orig.jpg
Translation
F. When a stop
codon is reached,
the new protein is
released from the
Ribosome
G. The order of
amino acids in a
protein is called
the protein or
amino acid
sequence
http://images.slideplayer.com/1/3615/slides/slide_25.jpg
Gene Expression
Translation
Let’s Watch a Movie:
http://207.207.4.198/pub/flash/26/transmenu_s.swf
Transcription & Translation Movie:
Review Questions
12. What types of RNA are associated with
ribosomes?
13. What do you call the 3-Nucleotide
sequences on tRNAs that recognize
codons?
14. What cellular machine reads the message
on an mRNA and makes protein?
15. What are the steps of Translation?
Mutations
A. Alterations in the DNA sequence that change amino acid
sequence are called Mutations
B. Mutations that change 1 or a few nucleotides are called
Point Mutations
C. There are several
types of Point
Mutations
1. Substitutions
2. Insertions
3. Deletions
http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/graphics/Mutation.04.GIF
Frameshift Mutation: a shift in the
reading frame of the genetic code.
Which of
these 3
mutations is a
frameshift
mutation?
Point Mutations – Substitution
A. One nucleotide is replaced (substituted for) by another
B. Sickle-cell Anemia is caused by a substitution mutation
in the gene for Hemoglobin
1. A is substituted for T
2. Valine is substituted for Glutamic Acid
http://www.bbc.co.uk/scotland/education/bitesize/higher/biology/genetics_adaptation/mutations1_rev.shtml
Point Mutations – Insertion
A. A new nucleotide is added
B. This changes the sequence of all the amino acids
following the insertion
C. The altered
protein
may be
shorter or
longer, and
may not
function
http://ghr.nlm.nih.gov/dynamicImages/understandGenetics/mutations_and_disorders/Insertion.jpg
Point Mutations – Deletion
A. One nucleotide is lost
B. This changes the sequence of all the amino acids
following the insertion
C. The altered
protein
may be
shorter or
longer, and
may not
function
http://biotech-adventure.okstate.edu/low/basics/protein/10-mutation/point_deletion/point_deletion.gif
Sometimes Substitutions have little
or no Effect
A. UCU to UGC or UCA – all code for Serine
1. No amino acid change
2. Conservative substitutions
B. UCU to ACU or GCU – code for different amino acids
1. The amino acid will change
2. These are substitution mutations
Do not Confuse Point Mutations with
Chromosomal Mutations!
A. Chromosomal mutations are Large
pieces of DNA
B. Point mutation- a change in a
single Nucleotide of DNA
http://www.stanford.edu/group/hopes/causes/mutation/f_q02mutation.jpg
Genetic Disease Review
protein
Sickle Cell
Anemia
Phenylketonuria
Tay-Sachs
Disease
Cystic Fibrosis
Huntington’s
Disease
Hemophilia
Hemoglobin
Phenylalanine
Hydroxylase
genetics
mutation
recessive substitution
CFTR
recessive
multiple
types
multiple
types
deletion
Huntingtin
dominant
insertion
Clotting Factor
recessive
multiple
types
recessive
Hexosaminidase recessive
(sex-linked)
Review Questions
16. What is a Point Mutation?
17. What is a:
a. Substitution mutation?
b. Insertion mutation?
c. Deletion mutation?
18. Will a mutation always produce a mutant
protein?
19. What are some mutagenic agents?