BIOL 2P02 Lecture Notes - Lecture 8: Transfer Rna, Small Nuclear Rna, Ribose

79 views8 pages

OC1151411

21 Jun 2018

School

Department

Course

Professor

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

Spring BIOL 2P02 Section 1 Lecture 8 21/06/2018

Central Dogma of molecular biology

oEntire genome is replicated during cell division

oFor transcription, only some of the genome is replicated

First step of gene expression

oEvery cell houses our DNA and only 1.2% is coding, so transcription is selective, it only

transcribes genes. It doesn’t transcribe every single gene in the cell. Some are turned on

and some are turned off

oWhere a gene is expressed, when it’s expressed and how much it is expressed all allows

different cell types and functions to exist

Differences b/n replication & transcription

oWhen looking at replication of DNA, both strands are replicated -> semi conservative

find more resources at oneclass.com

Unlock document

This preview shows pages 1-3 of the document.
Unlock all 8 pages and 3 million more documents.

Already have an account? Log in

Spring BIOL 2P02 Section 1 Lecture 8 21/06/2018

oTranscription factors bind to a promoter -> brings are machinery to the site and will

transcribe the DNA that has the promoter in it

Only one of the two strands are usually transcribed

Sometimes both can be transcribed if a promoter is on both strands

orNTP -> ribonucleotide triphosphate for transcription

oreplication uses a primer for initiating DNA polymerase

RNA polymerase doesn’t need a primer

A form of RNA polymerase is a primase

oTranscription products are single stranded (ss)

oThe selectively of transcription is key- > entire genome isn’t transcribing -> only very

specific -> protein coding or RNA gene

Transcription

oFirst step of gene expression

Also called DNA dependent synthesis

oRNA is synthesized using one strand of DNA as a template

= Primary RNA transcript

oPrimary transcript is processed to give a mature RNA

mRNA, tRNA

oASYMMETRIC

Only one strand is used as template (although both could be templates if they

had the correct regulatory sequences)

Reading the template strand from 3’ – 5’ but synthesizes the RNA 5’ -> 3’

find more resources at oneclass.com

Unlock document

This preview shows pages 1-3 of the document.
Unlock all 8 pages and 3 million more documents.

Already have an account? Log in

Spring BIOL 2P02 Section 1 Lecture 8 21/06/2018

Transcription bubble formed -> not like the unwinding of the DNA and a new

strand is added. It reanneals. The red is the template with the promoter and the

RNA is transcribed 5’->3’

The blue strand is complementary, the bubble is 5’ ->3’

Also called the coding strand

If the RNA is transcribed as the complement so the RNA sequence is the same as

the coding strand (except T and U)

2 Mg2+ present and are held by aspartic acid and incoming rNTP will be

attacked by the 3’-OH and PPi is released. The second Mg2+ stabilizes the

Phosphate

find more resources at oneclass.com

Unlock document

This preview shows pages 1-3 of the document.
Unlock all 8 pages and 3 million more documents.

Already have an account? Log in

Related Questions

13. The arms of a human and the wing of a bat are _________________ structures, composed of the same bones that have been modified for different functions.

analogous

vestigial

c.	homologous

d.	convergent

14. Xeroderma pigmentosum is an autosomal recessive genetic disorder. People who are homozygous for the disease-causing allele have skin that is damaged by exposure to ultraviolet radiation; this can lead to skin cancer at an early age. The mutation that causes this disorder is in a gene that functions:

a.	to repair DNA by excising (removing) nucleotides damaged by UV light.

b.	in lysosomes, to break down lipids that otherwise accumulate in the nervous system.

c.	to produce the UV blocking pigment melanin in the skin cells

d.	in red blood cells to carry oxygen to the skin.

15. The Amish are a religious sect descended from a small group of colonists who came to the United States over 200 years ago. Their religious beliefs have kept them isolated from society. The Amish have a much higher than average incidence of both polydactyly (extra fingers and toes) and dwarfism in their communities. This is most likely explained by:

a.	inheritance of acquired characters.

b.	the founder effect.

c.	disruptive selection.

d.	natural selection.

16. In the structure of DNA that Watson and Crick proposed, the sides of the "ladder" of the DNA molecule are always the same distance apart, making the molecule a constant width. This occurs because when the bases hydrogen bond to form the rungs of the "ladder", a:

a.	purine always pairs with a pyrimidine.

b.	purine always pairs with a purine.

c.	pyrimidine always pairs with a pyrmidine.

d.	The structure of the double helix is not determined by how the bases pair.

17. The RNA transcript of DNA that travels to the cytoplasm, carrying the instructions to make a protein, is called:

rRNA.

tRNA.

mRNA.

d.	RNA polymerase.

18. When DNA is replicated, the error rate is approximately one error for every 10,000 nucleotides copied. However, that error rate is reduced to only 1 error for every 1 billion nucleotides. The DNA sequence is "corrected" by:

a.	repeating S phase to see if the error rate is lower the second time around.

b.	enzymes that proofread the DNA and repair errors.

c.	messenger RNA during the process of transcription.

d.	Any errors made during DNA replication cannot be corrected. If errors are detected after S phase, the cell is destroyed.

19. Mendel's principle of segregation says that:

a.	when gametes are formed, each gamete receives only one allele for a particular gene.

b.	some genes are dominant to others.

c.	a testcross must be used to determine the genotype of an organism with a dominant phenotype.

d.	all of the above

20. Tay-Sachs disease is lethal before reproductive age, but the allele persists in Louisiana French Canadians because:

a.	it is a dominant allele.

b.	new mutations causing this disease are common in that population.

c.	it is not expressed in the phenotype of heterozygous individuals.

d.	the disease is contagious and can be transmitted by nonheritable means.

21. Physical features that are similar in organisms which are not closely related to each other are most likely a result of ____________. A good example of this is the similarities seen between some marsupial and placental mammals.

a.	natural selection.

b.	adaptation to similar environments

c.	convergent evolution

d.	All of the above phrases can be used to correctly fill this blank.

22. In humans, which of the following sex chromosome compliments could be found in males?

23. The proteins that are associated with eukaryotic chromosomes:

a.	help to package the DNA within the nucleus.

b.	are involved in gene expression, through binding with the DNA.

c.	may be replicating or transcribing the DNA.

d.	All of these are true of proteins that are associated with eukaryotic chromosomes.

24. A sequence of DNA nucleotides that contains the information to produce a single protein is a(n):

codon.

gene.

c.	polypeptide.

d.	anticodon.

whitelizard672

BIOL 2P02 Lecture Notes - Lecture 8: Transfer Rna, Small Nuclear Rna, Ribose

Get access

Related Documents

BIOL 2P02 Lecture Notes - Lecture 10: Methyl Group, Transferase, Point Mutation

BIOL 2P02 Lecture Notes - Lecture 4: Dna-Binding Domain, Dna Supercoil, Alpha Helix

BIOL 2P02 Lecture Notes - Lecture 9: Structural Change, Wild Type, Allosteric Regulation

Related Questions