chapter 10 - protein synthesis. chapter 10 vocabulary list 1.anticodon 2.codon 3.gene expression...
TRANSCRIPT
Chapter 10 - Protein Synthesis
Chapter 10 Vocabulary List
1. Anticodon
2. Codon
3. Gene expression
4. Genetic code
5. Messenger RNA
6. Point mutation
7. Intron
8. Exon
9. 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. Transcription1. Copying DNA into RNA
B. Translation1. 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
http://en.wikipedia.org/wiki/Adenosine_triphosphate
ATP
Transcription (TX)
A. The transfer of the protein blueprint from DNA into RNA1. DNA is too large
and valuable to let out of the nucleusi. It is the primary
computer code for the cell
2. RNA is a portable copyi. 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 enzyme1. Unwinds DNA and adds
nucleotides to make RNA2. Promoters- RNA polymerase
only binds to regions of DNA with specific sequences.
B. RNA is made following same base-pairing rules as for DNA replication1. Thymine is replaced by Uracil2. A – U and G – C
http://www.idigitalmotion.com/portfolio.htm
A = adenineT = thymineG = guanineC = cytosineU = uracil
Introns and ExonsA. Genes are made up of coding and noncoding sequenceB. Introns – noncoding
1. DNA that does not code for protein sequence
C. Exons – coding1. 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
http://www.iir.suite.dk/IIR/15genes/images/15DNAToProt2.gif
2. A portable copy of the DNA
B. Codons
1. 3-Nucleotide sequences that codes for a single amino acid
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
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/code.gif
Third letter
The Genetic Code
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 RNAA. 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
TranslationA. 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
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
http://www.google.com/imgres?imgurl=http://frank.itlab.us/spider_2002/translation.jpg&imgrefurl=http://frank.itlab.us/spider_2002/dna.html&usg=__jrmqoW6vkV0iIxaug6iXugrDnR4=&h=388&w=469&sz=28&hl=en&start=24&zoom=1&tbnid=ahLACycLUfHd4M:&tbnh=147&tbnw=178&ei=ioW1TdavBui40QGI6oD-CA&prev=/search%3Fq%3DProtein%2Btranslation%26hl%3Den%26safe%3Dactive%26client%3Dfirefox-a%26sa%3DG%26rls%3Dorg.mozilla:en-US:official%26biw%3D1280%26bih%3D810%26site%3Dsearch%26tbm%3Disch0%2C570&um=1&itbs=1&iact=hc&vpx=692&vpy=394&dur=749&hovh=204&hovw=247&tx=118&ty=91&page=2&ndsp=24&ved=1t:429,r:9,s:24&biw=1280&bih=810
II
III
IV
V
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://fc06.deviantart.net/fs17/i/2008/237/6/f/Protein_Synthesis_by_TheElephantMan.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
http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/graphics/Mutation.04.GIF
C. There are several types of Point Mutations1. Substitutions2. Insertions3. Deletions
Frameshift Mutation: a shift in the reading frame of the genetic code.
Which of these 3 mutations is a frameshift mutation?
Point Mutations – SubstitutionA. 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 – InsertionA. A new nucleotide is added
B. This changes the sequence of all the amino acids following the insertion
http://ghr.nlm.nih.gov/dynamicImages/understandGenetics/mutations_and_disorders/Insertion.jpg
C. The altered protein may be shorter or longer, and may not function
Point Mutations – DeletionA. One nucleotide is lost
B. This changes the sequence of all the amino acids following the insertion
http://biotech-adventure.okstate.edu/low/basics/protein/10-mutation/point_deletion/point_deletion.gif
C. The altered protein may be shorter or longer, and may not function
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!
http://www.stanford.edu/group/hopes/causes/mutation/f_q02mutation.jpg
A. Chromosomal mutations are Large pieces of DNAB. Point mutation- a change in a single Nucleotide of DNA
Genetic Disease Reviewprotein genetics mutation
Sickle Cell Anemia
Hemoglobin recessive substitution
PhenylketonuriaPhenylalanine Hydroxylase
recessivemultiple
types
Tay-Sachs Disease
Hexosaminidase recessivemultiple
types
Cystic Fibrosis CFTR recessive deletion
Huntington’s Disease
Huntingtin dominant insertion
Hemophilia Clotting Factor recessive (sex-linked)
multiple types
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?