BIOA01H3 Lecture 11: Lec 11 - f1

31 views3 pages

pinkzebra766

14 Aug 2018

School

Department

Course

Professor

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

3363410481 and 37710 others unlocked

BIOA01H3 Full Course Notes

Verified Note

18 documents

Document Summary

Each cell type expresses different sets of genes. We will consider: epigenetic control, transcriptional control, translational control. No change in the sequence of dna but modification of regions of dna or proteins that compact dna which determine whether transcription machinery has access to the genes. Tails are lysine rich " can be altered. If it is altered though methyl group it is further compacted, dna is not accessible. If altered though acetyl group, it loosens the region, accessible. Dna in chromatin is inaccessible to the transcription machinery until it is remodeled. Chemical modification of histone tails repositions nucleosomes and exposes stretches of dna to the transcription machinery. Occurs during development and in response to environmental cues. Pattern of modifications = histone code = affects chromatin structure and gene transcription. Part of the promoter region upstream of the gene is rich in c and g called cpg islands. Cytosine can be modified, regularly it is unmodified/unmethylated.

Related Questions

QUESTION 3

What is the purpose of chromatin-remodeling enzymes in human cells?

The enzymes control the rate of translation of an mRNA transcript

The enzymes add phosphate or methyl groups to histone tails

The enzymes slide nucleosomes farther apart or closer to each other

The enzymes send damaged proteins to the proteasome for degradation

The enzymes cause DNA looping to occur

QUESTION 10

If you can drink milk as an adult, it means that you have inherited a mutation in the an enhancer for your lactase gene (the gene that encodes the enzyme you need to break down lactose). Predict the effect of this mutation:

The mutation changes the number of domains in the enzyme, which makes it work more efficiently

The mutation changes the amino acid sequence of the lactase protein

The mutation increases the number of copies of the lactase gene that will be found in your genome

The mutation changes whether the lactase sequence is found in an intron or exon

The mutation affects the expression of the lactase gene

QUESTION 12

What determines where in the genome a transcription regulator will bind?

Transcription regulators bind to the 5' UTR region of a gene

Regulators bind via complementary base-pairing to certain DNA molecules

Covalent bonds form between the transcription regulator and the atoms of the DNA backbone

Every eukaryotic gene has a different transcription regulator that will bind to the 5' end of the gene

Transcription regulators bind to specific DNA sequences via multiple weak non-covalent interactions

QUESTION 15

What is the histone code used for?

		Phosphorylation and acetylation of DNA affect its ability to be compacted
		Changes to the sequence of DNA change whether DNA will wrap around histone proteins
		Covalent modifications of histones affect the ability of the transcription initiation complex to form
		Histones provide the codon sequences needed for translation to occur
		The histone code affects which amino acids will get added to a polypeptide

QUESTION 1

How is a bone marrow transplant able to treat someone with leukemia?

		The donor blood contains antibodies that destroy cancer cells
		Donor blood contains stem cells that regenerate cells in the immune system
		Bone marrow contains induced pluripotent stem cells that turn into red blood cells
		Bone marrow contains tumor supressor genes that slow down leukemia growth
		Bone marrow contains pluripotent human embryonic stem cells

1.2 points

QUESTION 2

What would happen if siRNAs designed to target mRNA from an oncogene were introduced into cancer cells?

		Increased genomic instability would result from adding foreign nucleic acids
		New mutations would arise in the oncogene
		The oncogene would be converted back into a proto-oncogene
		The siRNAs would compete with the oncogene's active site
		Production of the oncogene protein would decrease

1.2 points

QUESTION 3

What is the purpose of chromatin-remodeling enzymes in human cells?

		The enzymes control the rate of translation of an mRNA transcript
		The enzymes add phosphate or methyl groups to histone tails
		The enzymes slide nucleosomes farther apart or closer to each other
		The enzymes send damaged proteins to the proteasome for degradation
		The enzymes cause DNA looping to occur

1.2 points

QUESTION 4

If you wanted to resurrect the mammoth, how would you do it?

		Use somatic cell nuclear transfer to insert the mammoth genome into the egg of an elephant
		Use transcription factors to re-program adult cells from elephants into mammoth cells
		Change the gene expression patterns of elephants to increase production of mammoth genes
		Use siRNAs to decrease expression of elephant-specific genes in an elephant embryo

1.2 points

QUESTION 5

How is eukaryotic transcription initiated?

		RNA polymerase is recruited to the start codon by transcription factors
		RNA polymerase begins transcription at the enhancer sequence
		RNA polymerase is activated by binding to GTP
		An initiator tRNA binds to the ribosome
		A complex of proteins forms at the promoter of a gene

BIOA01H3 Lecture 11: Lec 11 - f1

BIOA01H3 Full Course Notes

Document Summary

Get access

Related Documents

BIOA01H3 Lecture Notes - Lecture 29: Histone Code, Methylation, Lysine

BIOA01H3 Lecture Notes - Lecture 5: Embryonic Stem Cell, Cell Potency, Cellular Differentiation

BIOA01H3 Lecture Notes - Lecture 32: Histone Code, Central Dogma Of Molecular Biology, Methylation

Related Questions