HLTB22H3 Lecture Notes - Lecture 1: Uvrabc Endonuclease, Electromagnetic Radiation, Thymine

21 views5 pages

indigoantelope333

12 Dec 2016

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Mutations and effect on gene expression: dna codes for a normal gene. Transcribed and translated to make a normal protein physical appearance of the gene. Will result in a normal phenotype normal functioning of that protein: mutational effects can result in either an abnormal protein or a protein that is totally absent. Folding of the protein after the gene has been modified, means the protein will have altered physical or chemical properties affecting binding. Point mutations: literally are a mutation at one point/nucleotide, various categories. Change of one nucleotide pair to another (a-t to g-c) Reversion of the base pair (c-g to g-c) Entire amino acid has changed in response to a point mutation. Amino acid changes due to point mutation but the amino acids the(cid:373)sel(cid:448)es are(cid:374)"t that (cid:272)he(cid:373)i(cid:272)ally dissi(cid:373)ilar, so (cid:374)o (cid:272)ha(cid:374)ge to phe(cid:374)otype. Poi(cid:374)t (cid:373)utatio(cid:374) o(cid:272)(cid:272)urs (cid:271)ut the a(cid:373)i(cid:374)o a(cid:272)id does(cid:374)"t (cid:272)ha(cid:374)ge due to wobble hypothesis.

Related Questions

Use this list of gene elements to answer the following questions: (a) Promoter
(b) Exon
(c) Enhancer

(d) Intron
(e) 5â untranslated region

(f) 3â untranslated region

Problem 1. Which of the above gene elements are transcribed? You may choose more than one answer.

Problem 2. Which of the above gene elements are translated? You may choose more than one answer.

Problem 3. Which of the above gene elements are regulatory? You may choose more than one answer.

Problem 4. Which of the above gene elements are coding? You may choose more than one answer.

Problem 6. A mutation occurs in a gene with the following sequence: AAGCT. An example of a deletion mutation in this sequence would be AACT (loss of G). Using AAGCT as your normal sequence, give an example for the following types of mutations

(a) Insertion (b) Transition

Problem 7. A mutation occurs in the coding region of a gene with the following sequence AAGTGC. The translated sequence is Lysine (AAG), Cysteine (TGC). Give an example of following types of mutation using AAGTGC as your normal sequence. Provide the translated sequence caused by the mutation. (Hint: You will need a codon table to translate the sequence)

(a) Synonymous mutation
(b) Non-synonymous missense mutation

Problem 8. Patient 1 has a tumor causing mutation in a pro-growth gene. The mutated protein allows the cell to grow without receiving growth signals from outside the cell. Is the mutated gene an oncogene or a tumor suppressor? Why? Which hallmark is the gene associated with?

Problem 9. Patient 2 has a tumor which contains a loss of function mutation in the P53 gene. How would you determine if it is a somatic or germ line mutation?

Problem 10. Patient 3 has a tumor causing mutation in a gene called telomerase. The function of telomerase is to lengthen the ends of chromosomes. What hallmark is telomerase associated with? Is the mutation gain of function or loss of function? (Hint: to answer this question, you need to understand which hallmark telomere length is associated with)

QuestionGroup: #21 Gene expression 2

Assigned as

Homework

The direct end result of gene expression is which of the following?

Amino acids

Translation

Proteins

Carbohydrates

Unanswered

Submit

QuestionGroup: #22 Mutation

Assigned as

Homework

Which of the following is the ways in which nucleotide mutations lead to altered proteins?

One nucleotide is substituted by another nucleotide, which can cause an early stop codon to be incorporated into the amino acid sequence resulting in a truncated protein.

One nucleotide is replaced by another nucleotide, which can change an amino acid in the protein sequence

Nucleotides are inserted into a nucleotide sequence causing a frameshift in the sequence.

All three choices may cause mutations.

Unanswered

Submit

QuestionGroup: #23 Mutation 2

Assigned as

Homework

Mutations are the result of which of the following?

Change in the normal nucleotide sequence in the DNA directly resulting in different carbohydrates

Change in the normal nucleotide sequence in the DNA directly resulting in different proteins

Change in the order of transfer RNA to messenger RNA so that the transfer RNA take over the role of Messenger RNA

Primarily an alteration in the sequence of nucleotides in the abnormal proteins

Unanswered

Submit

QuestionGroup: #24 Cell division

Assigned as

Homework

There are two major kinds of cell division. Which of the following plays a major role in promoting genetic diversity?

Meiosis since it causes the cells to make more daughter cells than mitosis

Mitosis since it causes the cells to duplicate and eventually have mutations

Meiosis since it causes the DNA sequences to be separated into new patterns in the daughter cells.

Mitosis since it essential for the ovaries in humans to separate and duplicate

Unanswered

Submit

QuestionGroup: #25 Cancer

Assigned as

Homework

Genes that slow down or stop the cell cycle are called...

Apoptotic genes

Oncogenes

Restriction genes

Tumor suppressor genes

Unanswered

Submit

QuestionGroup: #26 Cancer2

Assigned as

Homework

The common theme in the development of all cancers is...

Mutation

Evolution

Infection

Syncopation

Unanswered

Submit

QuestionGroup: #27 Genetics

Assigned as

Homework

Punnett's square is which of the following?

Example of all possible combinations of alleles

Example of all possible combinations of chromosomes

Example of only certain combination of alleles since some will not be expressed.

Example of all possible combinations of DNA

Unanswered

Submit

QuestionGroup: #28 Embryo development

Assigned as

Homework

Which of the following is the end of the cleavage phase?

A fetus

Formation of a blastocyst

Implantation to the lining of the uterus

Fewer number of cells

Unanswered

Submit

QuestionGroup: #29 Development of organ system

Assigned as

Homework

For organs to be differentiated, which of the following is the first step?

Stem cells trigger the development of differentiated cells

Tissues assemble into organ systems such as blood

Tissue specific genes in stem cells are triggered

Differentiated cells form tissues

Unanswered

Submit

QuestionGroup: #30 Development and society

Assigned as

Homework

A pregnant mother ingests a chemical which her mother said would be great for the baby. When the baby was born, it had a large head and flippers for arms. What caused this phenotype?

The chemicals were teratogens which influenced oxidative phosphorylation causing the changes in the phenotype.

The chemicals influenced the expression of different stem cells.

There is no way to assume the chemicals caused the phenotype since we have no data on other mothers who took this medicine. It could have been purely by chance.

The chemicals were teratogens which caused the baby to show early signs of evolution.

GENETICS QUESTION: For this experiment we focused on forward genetics: First, his- mutants were identified and then complementation analysis was used in order to determine which of the 7 his genes was mutated. ( The exact data can be seen at the bottom). In this experiment we screened for his- mutants that were generated via a random mutation process resulting from errors in DNA replication or induced by EMS aka Ethyl methanesulfonate. We compared a mutagenized culture that was treated with EMS and an un-mutagenized culture that was not treated with EMS. However, both cultures went trhough an enrichment process to increase the frequency of his- mutants.

Point mutations involve the substitution of one type of base pair for another. If the substitution replaces a purine with a purine (or a pyrimidine with a pyrimidine), it is called a transition. If the substitution replaces a purine with a pyrimidine (or a pyrimidine with a purine), it is called a transversion. Many mutagenic chemicals cause this type of mutation by alkylation of a nucleotide base. The chemically altered base can then be misread during replication or repair. For example the mutagen, ethyl methanesulfonate (EMS), adds an ethyl (-CH2-CH3) group to both guanine or thymine bases causing the modified guanine to pair with thymine and the modified thymine to pair with guanine.

1. Why might one gene be more susceptible to EMS mutagenesis than another gene?

2. Why might we have expected to find a higher frequency of polar mutants (his4A^-B^-C^-) in the unmutagenized culture compared to the mutagenized culture?

Table 2. Experiment 1B class data summary (number of his^-mutants by section) Unmutagenized
Section	1	2	3	*4ABC*	4A	4B	4C	5	6	7	*Total his^-* mutants**
Tuesday	7	1	5	4	2	1	9	2	3	1	35
Wednesday	2	1	14	0	4	2	2	4	8	2	39
Total	9	2	19	4	6	3	11	6	11	3	74
% each mutant	12.1	2.7	25.7	5.4	8.1	4.1	14.9	8.1	14.9	4.1	~100%

Mutagenized
Section	1	2	3	4ABC	4A	4B	4C	5	6	7	*Total his^-* mutants**
Tuesday	2	5	4	2	6	5	5	0	4	1	34
Wednesday	9	1	15	0	9	1	2	2	9	4	52
Total	11	6	19	2	15	6	7	2	13	5	86
% each mutant	12.8	7.0	22.1	2.3	17.4	7.0	8.1	2.3	15.1	5.8	~100%

HLTB22H3 Lecture Notes - Lecture 1: Uvrabc Endonuclease, Electromagnetic Radiation, Thymine

Document Summary

Get access

Related Documents

HLTB22H3 Lecture Notes - Lecture 8: Point Mutation, Purine, Pyrimidine

HLTB22H3 Lecture Notes - Lecture 1: Growth Factor, Apoptosis, Protein Dimer

LIFESCI 3 Chapter Notes - Chapter 12.1: Wild Type, Glutamine, Frameshift Mutation

Related Questions