MLB 111 UNIT 6
STUDY UNIT 6: FROM DNA TO PROTEIN: GENE EXPRESSION AND MUTATION (6 lectures)
STUDY MATERIAL: Hillis et al., Chapter 14 and Chapter 15.1
Lecturer: Dr Markus Wilken
Core Concepts:
● Section 14.1 Genes code for proteins
● Section 14.2 Information flows from genes to proteins
● Section 14.3 DNA is transcribed to produce proteins
● Section 14.4 Eukaryotic pre-mRNA transcripts are processed prior to translation
● Section 14.5 The genetic code determines the protein sequence encoded by an mRNA
● Section 14.6 The coding sequence in mRNA is translated into proteins by ribosomes
● Section 14.7 Polypeptides can be modified and transported during or after translation
● Section 15.1 Mutations are heritable changes in DNA
LEARNING OUTCOMES:
You have mastered this study theme when you can:
1. Briefly discuss the scientific experiment that involved mutant strains of Neurospora
crassa. Also relate how this led to the one gene - one polypeptide hypothesis, and what
this means for the modern understanding of gene expression.
1
,https://clickup.up.ac.za/ultra/courses/_181502_1/outline/file/_4363978_1
*See in textbook
Do not need to know the Beadle and Tatum Metabolic pathway!!!!!!
Things in body normally function from a pathway. Changed by gene. So if you change the
gene you change the product.
2. Explain what is meant by the “central dogma of molecular biology”.
Describes how information flows in the cell
• from DNA to DNA, from DNA to RNA, from RNA to protein
• DNA is used to make mRNA -> transcription
◦ In eukaryotes, some changes are made to the mRNA
• mRNA is moved to the cytoplasm
• mRNA is made into proteins -> translation
◦ rRNA in ribosomes make this happen. Brings proteins to match mRNA
3. Name the three types of RNA important in the central dogma, and briefly explain the
function of each.
mRNA
•
tRNA
2
, •
rRNA
•
4. List the six types of RNA produced in Eukaryotic cells (Table 14.1).
5. Explain how DNA is transcribed into RNA by referring to:
5 The structure of RNA.
6 The components needed for transcription to occur.
7 The role of RNA polymerase in transcription.
8 The events of the three steps in transcription.
6. Explain how a mature mRNA in Eukaryotes is derived, and how it relates to the DNA
from which the mRNA was transcribed. You should refer to:
(a) The 5’ cap
(b) The poly-A tail
(c) RNA splicing
7. Explain the most important characteristics of the genetic code, including how it is used
to determine the amino acid sequence that will be produced by a nucleotide sequence.
8. Describe in detail the synthesis of proteins from mRNA. This includes
(a) The role of an aminoacyl-tRNA in charging a tRNA molecule.
(b) The role of loaded tRNAs in the translation process
(c) The relationship between the number of amino acids, aminoacyl-tRNA synthetases and
codons.
(d) The structure of the ribosome and how the ribosome is assembled for translation in
prokaryotes and eukaryotes.
(e) The role of the ribosome in translation by referring to the cycling to the tRNA through
the A, P, and E sites.
9. Discuss the role of a polysome in increasing the rate of translation.
10. Briefly discuss the cellular fate of proteins by referring to the function of the signal
sequence.
3
STUDY UNIT 6: FROM DNA TO PROTEIN: GENE EXPRESSION AND MUTATION (6 lectures)
STUDY MATERIAL: Hillis et al., Chapter 14 and Chapter 15.1
Lecturer: Dr Markus Wilken
Core Concepts:
● Section 14.1 Genes code for proteins
● Section 14.2 Information flows from genes to proteins
● Section 14.3 DNA is transcribed to produce proteins
● Section 14.4 Eukaryotic pre-mRNA transcripts are processed prior to translation
● Section 14.5 The genetic code determines the protein sequence encoded by an mRNA
● Section 14.6 The coding sequence in mRNA is translated into proteins by ribosomes
● Section 14.7 Polypeptides can be modified and transported during or after translation
● Section 15.1 Mutations are heritable changes in DNA
LEARNING OUTCOMES:
You have mastered this study theme when you can:
1. Briefly discuss the scientific experiment that involved mutant strains of Neurospora
crassa. Also relate how this led to the one gene - one polypeptide hypothesis, and what
this means for the modern understanding of gene expression.
1
,https://clickup.up.ac.za/ultra/courses/_181502_1/outline/file/_4363978_1
*See in textbook
Do not need to know the Beadle and Tatum Metabolic pathway!!!!!!
Things in body normally function from a pathway. Changed by gene. So if you change the
gene you change the product.
2. Explain what is meant by the “central dogma of molecular biology”.
Describes how information flows in the cell
• from DNA to DNA, from DNA to RNA, from RNA to protein
• DNA is used to make mRNA -> transcription
◦ In eukaryotes, some changes are made to the mRNA
• mRNA is moved to the cytoplasm
• mRNA is made into proteins -> translation
◦ rRNA in ribosomes make this happen. Brings proteins to match mRNA
3. Name the three types of RNA important in the central dogma, and briefly explain the
function of each.
mRNA
•
tRNA
2
, •
rRNA
•
4. List the six types of RNA produced in Eukaryotic cells (Table 14.1).
5. Explain how DNA is transcribed into RNA by referring to:
5 The structure of RNA.
6 The components needed for transcription to occur.
7 The role of RNA polymerase in transcription.
8 The events of the three steps in transcription.
6. Explain how a mature mRNA in Eukaryotes is derived, and how it relates to the DNA
from which the mRNA was transcribed. You should refer to:
(a) The 5’ cap
(b) The poly-A tail
(c) RNA splicing
7. Explain the most important characteristics of the genetic code, including how it is used
to determine the amino acid sequence that will be produced by a nucleotide sequence.
8. Describe in detail the synthesis of proteins from mRNA. This includes
(a) The role of an aminoacyl-tRNA in charging a tRNA molecule.
(b) The role of loaded tRNAs in the translation process
(c) The relationship between the number of amino acids, aminoacyl-tRNA synthetases and
codons.
(d) The structure of the ribosome and how the ribosome is assembled for translation in
prokaryotes and eukaryotes.
(e) The role of the ribosome in translation by referring to the cycling to the tRNA through
the A, P, and E sites.
9. Discuss the role of a polysome in increasing the rate of translation.
10. Briefly discuss the cellular fate of proteins by referring to the function of the signal
sequence.
3
