MGY377H1 Final: Exam study notes

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redtermite204

23 Dec 2011

School

UTSG

Department

Molecular Genetics and Microbiology

Course

MGY377H1

Professor

William Navarre

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Document Summary

Gram positive contains lots of petptidoglycan, unlike gram negative bacteria. Isotonic solute solution same molecular density outside of cells membrane still remains because no water influx but produce protoplast. After you disrupt the cell; pg layer maintains shape. Two sugars nag and nam linked to four to five amino acid peptide composition vary among bacteria but common property. D amino acid l is most natural configuration of amino acids, so bacteria produce d configuration so resistant to protease, most of which recognize only the l configuration. Transglycosylase important for joining subunits to form chain. Once glycol chain is made, peptide subunits can be crosslinks between different. Crosslink between fourth alanine and middle subunit last alanine is cleaved. If not additional crosslinking occurs, carboxylase can trim off terminal alanine. Third position in gram negative, mdap; in gram positive, it s l-lys. In gram negative, cross-linking between dap is direct peptide bond between residues.

Related Questions

Many antibiotics work by preventing the proper synthesis of the peptidoglycan cell wall. These antibiotics are most likely to be effective against what types of bacteria?

Gram-positive bacteria

Gram-negative bacteria

Gram-neutral bacteria

Either gram-positive or gram-negative bacteria

All of these

yellowhare287

1.This week, you will be conducting Gram stains of bacteria.Which of the following statements are true? (Mark all thatapply)

		Gram-negative bacteria do not stain purple because they do nottake-up crystal violet or iodine
		The peptidoglycan in the walls of Gram-positive bacteria bindsto the crystal violet stain more easily than walls of Gram-negativebacteria do
		Gram-positive bacteria have cell walls with a thickerpeptidoglycan layer than walls of Gram-negative bacteria
		Gram-negative bacteria do not stain purple, because their cellwall structure allows purple-colored iodine-dye complexes to washout of the cells more easily than the cell wall structure ofGram-positive bacteria does
		Gram-negative bacteria have an outer membrane (outside thepeptidoglycan layer in their wall) that Gram-positive bacterialack

What evidence is used to inform our understanding ofrelationships among species? (mark all that apply)

		Biochemical similarities between existing species
		Fossils
		Morphological similarities between existing species (presence ofhair, backbones, etc.)
		DNA sequences and molecular clocks

For each of the groups of organisms below, indicate whether theybelong in (A.) Archaea, (B.) Bacteria, or (C.) Eukarya

- A. B. C.	Methanogens (prokaryotes that produce methane)
- A. B. C.	Gram-positive bacteria
- A. B. C.	Fungi
- A. B. C.	Animals
- A. B. C.	Cyanobacteria
- A. B. C.	Green algae
- A. B. C.	Red algae
- A. B. C.	Amoebas
- A. B. C.	Thermophiles (prokaryotes of hydrothermal vents)
- A. B. C.	Plants
- A. B. C.	Free-living relatives of mitochondria
- A. B. C.	Single-celled organisms with a circular strand of DNA, without anuclear envelope and without peptidoglycan in their cell walls

Select all true statements about the relative diversity ofdifferent groups of organisms from among the followingstatements:

		There are more species of plants on Earth than species ofmolluscs
		There are more plant species on Earth than mammal species
		There are more species of plants on Earth than species offungi
		There are more species of fungi on Earth than mammal species
		There are more species of plants on Earth than species ofarthropods
		There are more flatworm species on Earth than mammal species

beigegerbil183

HELP WITH BIO MULTI CHOICE QUESTIONS:

QUESTION 2

Which of the following structures discussed in class is NOT found on all bacteria?
Flagella
Capsid
Fimbria
Plasma membrane

QUESTION 3
You are presented with a strain of bacteria that is resistant to the antibiotic penicillin. What steps would you take to confirm that you have a resistant bacterium?
Perform a Gram stain to determine pink stained Gram-positive bacteria.
Perform a Gram stain to determine purple stained Gram-positive bacteria.
Perform a Gram stain to determine pink stained Gram-negative bacteria.
Perform a Gram stain to determine purple stained Gram-negative bacteria.

QUESTION 4
With respect to bacterial growth into a fresh culture tube containing nutrient broth, at which phase do organisms undergo binary fission the most rapidly?
Lag phase
Stationary
Exponential
death

QUESTION 5
How would antibiotic resistance be passed from one bacterium to another bacterium?
Through the flagella via a plasmid.
Through the sex pilus via chromosomal DNA.
Through the sex pilus via a plasmid.
Through the flagella via chromosomal DNA.

QUESTION 6
When an F plasmid integrates into the host chromosome, the strain is referred to as

Hfr.
F'.
F-.
F+.

QUESTION 7
If you remove the peptidoglycan layer from a Gram-positive cell, it would still stain purple with a Gram stain (T/F).
True
False

QUESTION 8
During infection with a bacteriophage, bacterial DNA is packaged into a capsid and will:

be integrated into the genome of a new bacterium upon ligation.
be integrated into the genome of a new virion upon recombination.
be integrated into the genome of a new bacterium upon recombination.
be integrated into the genome of a new virion upon liagation.

QUESTION 9
Which of the following statements best describes most bacteria?
They are generally harmful.
They are limited to living in a few habitats.
They are very common in the environment.
They are responsible for the âcommon cold.â

QUESTION 10
Prokaryotes lack some parts found in eukaryotic cells, including which item?
a nuclear membrane
DNA
one or more chromosomes
a plasma membrane
all of the above

QUESTION 11
With respect to gram negative bacteria, what is the order of the bacterial cell structure from outside to inside?
Thin peptidoglycan layer, plasma membrane

thick peptidoglycan layer, plasma membrane

outer membrane, thick peptidoglycan layer, plasma membrane

outer membrane, thin peptidoglycan layer, plasma membrane

QUESTION 12
In transformation, a piece of DNA from a dead host can be taken up by living host

True
False

MGY377H1 Final: Exam study notes

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