MICI 3119 Lecture Notes - Lecture 1: Inclusion Bodies, Cell Envelope, G Cell

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plumlouse226

5 Feb 2018

School

Dalhousie University

Department

Microbiology & Immunology

Course

MICI 3119

Professor

Lee Song

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Document Summary

What is bacterial physiology: the study of structures and functions of bacterial cells and their components, structures : Cell envelope, surface appendages, inclusion bodies, endospores, secreted proteins : functions : Growth & reproduction, metabolism, motility, interactions with host and environment. Course objectives: provide students with fundamentals of bacteriology (i. e. structures & functions), give students an appreciation of the complex physiological processes within the bacterial cells that are needed for the interaction with the host and environment. Course contents: molecular architecture and assembly of cell parts, gene expression and genetics, metabolism and energy production, utilization of energy for cell activities, adaptation responses to host and environmental challenges, and host-pathogen interactions. Cell envelope: outer membrane, cell wall (peptidoglycan) Phagocytosis: uptake by white blood cells: streptococcus pneumoniae b. bacteroides sp, flagella ( agellum, also called h- antigen, long, threadlike proteinaceous structures. Consist of three parts: basal body, hook,

Related Questions

__________ are fairly small organelles that provide a safe place within the cell to carry out certain biochemical reactions that generate harmful, highly reactive oxygen species. These chemicals are both generated and broken down in the same location.

Lysosomes

Endosomes

Peroxisomes

Nucleosomes

Biologists cannot possibly study all living species. Instead, they try to understand cell behavior by studying a select subset of them. Which of the following characteristics are useful in an organism chosen for use as a model in laboratory studies?

rapid rate of reproduction

all of the above

ability to grow under controlled conditions

amenability to genetic manipulation

By definition, prokaryotic cells do not possess __________.

ribosomes.

a nucleus.

membrane bilayers.

replication machinery.

Cell biologists employ targeted fluorescent dyes or modified fluorescent proteins in both standard fluorescence microscopy and confocal microscopy to observe specific details in the cell. Even though fluorescence permits better visualization, the resolving power is essentially the same as that of a standard light microscope because the resolving power of a microscope is limited by the __________ of light.

intensity

absorption

wavelength

filtering

Choose the phrase that best completes this sentence: Microtubules ____________ and are required to pull duplicated chromosomes to opposite poles of dividing cells.

generate contractile forces

can rapidly reorganize

are found in especially large numbers in muscle cells

are intermediate in thickness

Despite the differences between eukaryotic and prokaryotic cells, prokaryotes have proteins that are distantly related to eukaryotic actin filaments and microtubules. What is likely to be the most ancient function of the cytoskeleton?

cell division

cell motility

vesicle transport

membrane support

DNA and RNA are different types of nucleic acid polymer. Which of the following is true of DNA but not true of RNA?

It contains thymine.

It has 5'-to-3' directionality.

It is single-stranded.

It contains uracil.

Double covalent bonds are both shorter and stronger than single covalent bonds, but they also limit the geometry of the molecule because they ____________________.

prevent additional bonds from being formed with the bonded atoms.

limit the rotation of the bonded atoms.

create a new arrangement of electron shells.

change the reactivity of the bonded atoms.

Drosophila melanogaster is a/an __________. This type of animal is the most abundant of all animal species, making it an appropriate choice as an experimental model.

mammal

amphibian

bird

insect

10.

If the isotope 32S has 16 protons and 16 neutrons, how many protons, neutrons, and electrons will the isotope 35S have, respectively?

16, 19, 17

16, 19, 15

16, 19, 16

16, 20, 15

11.

Living systems are incredibly diverse in size, shape, environment, and behavior. It is estimated that there are between 10 million and 100 million different species. Despite this wide variety of organisms, it remains difficult to define what it means to say something is alive. Which of the following can be described as the smallest living unit?

cell

organelle

protein

DNA

12.

Macromolecules in the cell can often interact transiently as a result of noncovalent interactions. These weak interactions also produce stable, highly specific interactions between molecules. Which of the factors below is the most significant in determining whether the interaction will be transient or stable?

the concentration of each molecule

the size of each molecule

surface complementarity between molecules

the rate of synthesis

13.

Many of the mechanisms that cells use for maintenance and reproduction were first studied at the molecular level in bacteria. Which bacterial species had a central role in advancing the field of molecular biology?

E. coli

S. pombe

C. elegans

D. melanogaster

14.

Many types of cells have stores of lipids in their cytoplasm, usually seen as fat droplets. What is the lipid most commonly found in these droplets?

cholesterol

isoprene

triacylglycerol

palmitic acid

15.

Mitochondria contain their own genome, are able to duplicate, and actually divide on a different time line from the rest of the cell. Nevertheless, mitochondria cannot function for long when isolated from the cell because they are __________________.

anaerobes.

viruses.

parasites.

endosymbionts.

16.

Mitochondria perform cellular respiration, a process that uses oxygen, generates carbon dioxide, and produces chemical energy for the cell. Which answer below indicates a correct pairing of material âburnedâ and the form of energy produced during cellular respiration?

17.

Polar covalent bonds are formed when the electrons in the bond are not shared equally between the two nuclei. Which one of these molecules contains polar bonds?

QUESTION 1

Which of the following statements about the bacterial cytoplasmic membrane is false?

	a.	It resists attachment of the bacterial chromosome to its inner surface.
	b.	It contains a protein complex that drives ATP synthesis.
	c.	It is asymmetric.
	d.	It consists of relatively equal amounts of phospholipids and proteins.

1 points

QUESTION 2

Which of the following statements regarding Mycobacteria is false?

	a.	The genome has relatively low Guanine (G) and Cytosine (C) content.
	b.	The cytoplasmic membrane is surrounded by a polymer (peptidoglycan) consisting of alternating N-Acetylglucosamine (NAG) and N-Acetylmuramic (NAM) acid units.
	c.	It infects approximately one-third of the global human population.
	d.	It has a Gram-positive cell wall with an additional waxy lipid layer of mycolic acid.

1 points

QUESTION 3

Which of the following outer membrane porins enables Mycobacteria to adapt to acidic and intracellular environments, and shows homology to outer membrane porin A?

	a.	OmpATb.
	b.	OmpA.
	c.	MspA.
	d.	Lipid A.

1 points

QUESTION 4

Based on your understanding of bacterial membranes, which of the following is not likely to be found in an E. coli outer membrane?

	a.	Membrane-anchored enzymes.
	b.	Mycolic acid.
	c.	Lipopolysaccharide.
	d.	Porin channels.

1 points

QUESTION 5

Based on the conclusions of this paper, which of the following statements would the author most likely disagree with?

	a.	Some archaeon do not contain all of the genes essential for life.
	b.	The membrane structures of prokaryotes show far greater diversity than those of eukaryotes.
	c.	As demonstrated in this definitive report, scientists have a great understanding of the majority of basic functions and evolution of bacterial membranes.
	d.	The outer membrane (and its associated components) of archaea, Gram-negative bacteria, and Gram-positive bacteria likely evolved independently of one another.

1 points

QUESTION 6

Which of the following is not true for Gram-negative, acid-fast, and archaeal membranes?

	a.	They modify their lipid content in response to environmental changes.
	b.	They have co-evolved the same outer membrane composition and structure.
	c.	They all have a cytoplasmic membrane.
	d.	Membrane transport proteins regulate nutrient uptake and waste removal.

1 points

QUESTION 7

Compared to Mycobacteria, Gram-negative bacterium contain:

	a.	More mycolic acid.
	b.	Pores of increased length.
	c.	Less peptidoglycan.
	d.	50-fold-lower numbers of porins.

1 points

QUESTION 8

Archaea are found to survive in strongly acidic lakes compared to bacteria and Eukaryotes. Which of the following supports this claim according to the study?

	a.	The presence of L-glycerol ether linked lipids in Archaea membranes.
	b.	The presence of D-glycerol ether linked lipids in Archaea membranes.
	c.	The presence of L-glycerol ester linked peptidoglycans in Archaea membranes.
	d.	The presence of L-glycerol ester linked lipids in Archaea membranes.

1 points

QUESTION 9

Based on your understanding of the symbiotic relationship between Nanoarchaeum equitans and Ignicoccus, which of the following below is not true?

	a.	The membrane lipids of N. equitans are synthesized by Ignoccocus.
	b.	In exchange for membrane lipids, N. equitans provide Ignicoccus with many essential cytoplasmic enzymes.
	c.	N. equitans lack enzymes capable of catalyzing lipid biosynthesis.
	d.	Intraperiplasmic vesicles produced by Ignicoccus allow for lipid transfer to N. equitans.

1 points

QUESTION 10

What is the role of hydrogen bonds in bacteria, as mentioned in the article?

	a.	They mediate transmembrane electron flow.
	b.	They mediate lipid biosynthesis.
	c.	They help to stabilize the cytoplasmic membrane.
	d.	They are responsible for the selective permeability of the cytoplasmic membrane.

HELP ASAP; Please help me understand my lab results, so be detailed to clearly understand

Then , Please include answers to the question below to include in your response

1. what role does ampicilin (amp) and arabinose (ara) play in the experiment.

2) Because GFP was isolated from jelly fisht, what modification to the GFP DNA had to be made to result in expression in E. coli?

BACKGROUND INFORMATION

Transformation of GFP and the pGLO Plasmid GFP is a commonly used reporter protein in research labs, as the fluorescence creates a marker protein that can be used in many types of cell biology and biochemical studies. In basic research, GFP is often fused to a specific target protein of interest, creating a chimeric reporter protein. GFP has been used as a reporter protein to study blood vessel and tumor progression in mice, brain activity in mice, and malaria eradication in mosquitoes for instance (see website mentioned in notes). In the first week you will use a procedure to genetically transform bacteria with the gene that codes for Green Fluorescent Protein. Following the transformation procedure, the bacteria express their newly acquired jellyfish gene and produce the fluorescent protein, which causes them to glow a brilliant green color under ultraviolet light. During the second week you will purify the protein away from all of the other proteins produced by the bacteria using chromatography, and during the third week you will evaluate the success of the purification procedure and estimate the size (molecular weight) of GFP by using sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). Fundamental to the process of genetic transformation of bacteria are plasmids. In addition to one large chromosome, bacteria naturally contain one or more small circular pieces of DNA called plasmids. Plasmid DNA usually contains genes for one or more traits that may be beneficial to bacterial survival. In nature, bacteria can transfer plasmids back and forth allowing them to share these beneficial genes. This natural mechanism allows bacteria to adapt to new environments. The occurrence of bacterial resistance to antibiotics is due in large part to the transmission of plasmids which contain antibiotic resistance genes. The pGLO plasmid contains the gene for GFP, and also contains the gene for the enzyme Î²-lactamase (bla), which provides resistance to the antibiotic ampicillin. The Î²-lactamase protein is produced and secreted by bacteria that contain the plasmid. Î²-Lactamase inactivates the ampicillin present in the LB nutrient agar, allowing bacterial growth. Only transformed bacteria that contain the plasmid and express Î²-lactamase can survive on plates that contain ampicillin. Only a very small percentage of the cells take up the plasmid DNA and are transformed. Untransformed cells cannot grow on the ampicillin selection plates. pGLO also incorporates a special gene regulation system, which can be used to control expression of the fluorescent protein in transformed cells. The gene for GFP can be switched on in transformed cells by adding the sugar arabinose to the cellsâ nutrient medium. Selection for cells that have been transformed with pGLO DNA is accomplished by growth on antibiotic plates. Transformed cells will appear white (wild-type phenotype) on plates not containing arabinose, and fluorescent green when arabinose is included in the nutrient agar medium.

The transformation procedure involves three main steps. These steps are intended to introduce the plasmid DNA into the E. coli cells and provide an environment for the cells to express their newly acquired genes. 1) Cells are first treated with a solution of CaCl2, which is thought to neutralize the repulsive negative charges of the phosphate backbone of DNA and the phospholipids of the cell membrane, allowing the DNA to adhere to the cells. This is referred to making the cells âcompetentâ (i.e. the cells are capable, or competent, to take-in exogenous DNA). 2) Cells are then subjected to a heat shock, which is thought to increase the permeability of the cell membrane, allowing the cells to take-in the plasmid DNA. 3) Cells are allowed to grow in a ârecoveryâ phase in the absence of ampicillin. During this time the cells begin to produce the Î²-lactamase protein, which will allow them to survive when they are subsequently placed on agar plates containing ampicillin.

For the first week section of lab

To eac

h of two microfuge tubes, add 250ul of transformation buffer. Keep these tubes on ice.

Using a sterile loop, pick one colony of bacteria from the LB plate. Transfer this colony to one of the microfuge tubes.

Gently vortex the tube until the colony is dispersed. Repeat for the second tube. Add 0.08ug of DNA to one of these tubes (+DNA tube).

Incubate both tubes on ice for 10 minutes. Incubate both tubes at 42Â°C for 50 seconds.

Incubate both tubes on ice for 2 minutes. Add 250ul of LB broth to each tube and incubate at room temperature for 10 minutes. Flick each tube gently. Add 100ul of t

his transformation mix to the appropriate plates.

Results For plates:

+DNA: Has the E. Coli pGlo plasmid and - DNA plates do no have EColi pGLo plasmid .

Amp means ampiclin and Ara means arabinose on agar plates

+ DNA Plate LB/amp/ara--> white 9 colonies, Glow: yes

+DNA LB/amp--> 7 colonies, GLow: no

--DNA LB/AMP- 1 colony so no colony growth and no glovw

-DNA: LB--> many colonies, Glow: no

Please explain significance of result or thand the reason for the results in scientific terms based on the background information provided and your own knowledge to be detailed. Would these results be expected as wll.

MICI 3119 Lecture Notes - Lecture 1: Inclusion Bodies, Cell Envelope, G Cell

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