BIO 319 Lecture Notes - Lecture 24: Lambda Phage, Shiga Toxin, Lysogenic Cycle

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periwinklelouse832

18 Dec 2018

School

University at Buffalo

Department

Biological Sciences

Course

BIO 319

Professor

Gollnick Paul

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Document Summary

Materials for previous lectures that are needed for comprehension. Sigma factor ( factor): is a protein needed for initiation of transcription in bacteria. It is a bacterial transcription initiation factor that enables specific binding of rna polymerase to gene promoter. Camp act as an activator in the lac operon analogy to how cll needed for pre promoter activation. This is important to understand since many bacterial disease are actually the result of lysogenic. Phage within the bacteria, the gene for the toxins resided in the phage of the dna (ex: e. coli and shiga toxin that is produced by a phage that is close to lambda) Prophage: phage dna integrated into the host genome. Rna virus: utilizes rna polymerase which doesn"t have proofreading mechanism hence very high mutation rates. Phages can follow two life cycles either lytic life cycle or the lysogenic life cycle. Always looking for new victim since these destroy the population.

Related Questions

QUESTION 10

If you can drink milk as an adult, it means that you have inherited a mutation in the promoter of 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

1.2 points

QUESTION 11

A competitive inhibitor is decreasing the activity of an enzyme. Predict the effect of adding more substrate to the reaction.

		The substrate will increase the reaction rate by binding to the allosteric site
		The substrate will increase the reaction rate by competing with the inhibitor for the active site
		The reaction rate will not change unless the inhibitor can be removed
		The enzyme adjusts its shape so that the substrate, but NOT the competitive inhibitor, can bind
		The substrate will bind to the competitive inhibitor and block its ability to bind to the enzyme

1.2 points

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

1.2 points

QUESTION 13

What is the basic premise of cell theory?

		DNA -> RNA -> protein
		All cells arise from pre-existing cells
		DNA provides the complete instructions to create a cell
		The identity of a cell is determined through gene expression patterns
		All cells contain the same four basic macromolecules

1.2 points

QUESTION 14

What is the benefit of using BOTH the lac activator and the lac repressor to control gene expression?

		Using both an activator and repressor enables cells to more accurately determine the amount of lactose available in the environment
		Enzymes to digest lactose are only made when energy is low and lactose is available
		The activator can override the inhibition of the lac operon by the repressor
		The repressor can control the enhancer, while the activator can control the promoter
		When neither the lac activator or repressor is present, expression of the lac operon is too high

1.2 points

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

BIO 319 Lecture Notes - Lecture 24: Lambda Phage, Shiga Toxin, Lysogenic Cycle

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