Chapter 5: cell biology of bacteria Flashcards by Yaz Bassi

cells without a “true” nucleus (no nuclear membrane)
Bacteria and Archaea
Genome or DNA is spread throughout middle of cell

Prokaryotic cells

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cells with a “true” nucleus and other organelles.
animals, plants, and protists

Eukaryotic cells

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Bacteria or Eukaryotes

small cell size (usually 0.2-10mcg)

bacteria

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Bacteria or Eukaryotes

DNA organized in nucleoid throughout the cytoplasm

bacteria

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Bacteria or Eukaryotes*

wide range of cell size, from very small to very large (0.2 mcg to 1mm)

Eukaryotes

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Bacteria or Eukaryotes

DNA contained in nucleus enclosed by nuclear membrane

Eukaryotes

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Bacteria or Eukaryotes

small genome (0.5-15 million base pairs)

bacteria

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Bacteria or Eukaryotes

wide range of genone size, including very large (0.5 million-20 billion base pairs)

Eukaryotes

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**Bacteria or Eukaryotes

circular chromosome (usually) although may have mutiple circular and linear chromosomes

Bacteria

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Bacteria or Eukaryotes

Linear chromosomes

Eukaryotes

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Bacteria or Eukaryotes

cell wall composed of peptidoglycan

bacteria

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Bacteria or Eukaryotes

cell walls of plants and fungi composed of various carbohyrates (such as cellulose or chitin), but never peptidoglycan

Eukaryotes

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bacterial cell wall

the cytoplasm of the bacterial cell is composed of?

a gel like network of proteins and macromolecules

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bacterial cell wall

The cytoplasm is contained by the?

cell membrane

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bacterial cell wall

Outside of the cell membrane the cell body is enclosed by the?

cell wall

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bacterial cell wall

the cell wall is made up of?

peptidoglycan

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bacterial cell wall

outside the cell wall, Gram negative (-) bacteria have a?

outer membrane

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bacterial cell wall

the cell membrane, cell wall, and outer membrane (gram (-) constitutes the?

cell envelope

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bacterial cell wall

the chromosome is organized within the cytoplasm as a system of looped coils called the?

Nucleoid

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what is the difference between ribsomes in prokaryotic cells and eukaryotic?

eukaryotic cells have ribosomes with 40 and 60 subunits.
prokaryotic cells have ribsomes with 30 and 50 subunits

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what is the cell wall made of?

glycan chains and peptide cross bridges

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what does the cell wall protect the cell from?

osmotic shock

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Penicillin and vancomycin blocks the?

peptide cross bridge formation

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Penicillin binds specifically to a bacterial _____________?

enzyme called transpeptidase

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vancomycin binds directly to the

terminal D-alanine residues of the peptidoglycan chains

a disaccharide unit of glycan has an attached A) of four to six B) attached to the NAM termminal

A) peptide B) amino acids

# Bacillus anthracis, Streptococcus pyogenes Thick cell wall, multiple layers of peptidoglycan

Gram positive

# Escherichia coli, Pseudomonas aeruginosa thin cell wall, single layer of peptidoglycan

Gram negative

Gram positive bacteria will be stained what colour?

purple (: "positively purple"

Gram negative bacteria will be stained what colour?

pink (:

what classification of bacteria has the presence of Teichoic acids?

Gram positive

(blank) acts as “bacterial signature” molecules that alert the immune system of an impending infection

Teichoic acids

What does the outer membrane of gram negative cells consist of?

phospholipids, LPS, and a long polysaccharides

* extends outwards from the core oligosaccharide. * is not embedded into the membrane.

O-antigen

* attached to lipid A. * extends outward but not embedded in the membrane.

core oligosaccharide

* embedded in the bacterial outer membrane. * fatty acid chains anchor LPS into the membrane. * responsible for endotoxic effects when killed.

Lipid A

Inner leaflet of the outer membrane that forms a peptide bond with peptidoglycan. Can stimulate a inflammatory and immune response.

Murein lipoprotein

outer leaflet of the outer membrane, lipid A and polysaccharide chains

Lipopolysaccharide (LPS)

Acts as an endotoxin in lysed cells, so antibiotic treatment can kill cells but can also cause endotoxic shock in patients

Lipid A

Mycobacteria have a unique envelope that consists of peptidoglycan and (blank)

mycolic acid

are mycobacteria gram negative or positive?

positive!

A helical protein filament whose rotary motor propels the cell in search of a more favourable environment

Flagellum

in E.coli. the flagella (blank) a) detach from the cell body b) extend freely outside of the cell. c) wrap around the cell body d) e.coli do not have flagella

extend freely outside of the cell.

in Borrelia burgdorferi or treponema pallidum the flagella (blank)? a) Wrap outside of the cell body b) wrap around the cell body c) coil inside of the cell body d) detach from the cell body

wrap around the cell body

* Involves rotation of the flagella that propels the cell in response to stimuli, * Most flagellated cells have an elaborate sensory system, that enables them to swim toward favorable environments

chemotaxis

This rotation moves cell **toward** attractant

counterclockwise

this rotation **stops** the forward motion so, cell tumbles and changes direction

clockwise

What are pili made of?

Pilin protein

short attachment pili

fimbriae

facilitates transfer of DNA between cells

conjugation (sex) pilus

membranous extensions of cytoplasm that secrete adhesion factors

stalks

# **bacterial cell division steps** 1) a).. 2) protein synthesis and expansion of cytoplasm causes cell to b)... 3) c).. forms and the cell divides

a) DNA replication b) elongate c) septum

If division occurs in different directions we get clusters which is what bacteria?

staph

If division occurs in the same direction we get a linear line which is what bacteria?

strep

Gene expression can be turned **on**, which is called?

induction (up-regulation)

Gene expression can be turned **off**, which is called?

repression (down-regulation)

protein that stops gene expression

repressor protein

Transcription and translation and mRNA degradation can occur simultaneously **true or false?**

True

Enzyme responsible for transcription in prokaryotes

RNA polymerase

The DNA sequence where transcription starts

Promoter

Transcription and translation and mRNA degradation can occur simultaneously =

coupling

a mass of bacteria that stick to and mutiply on a solid surface

biofilm

Biofilms can be single species or mutiple collaborating species **True or false**

True

biofilms grow on a) organic surfaces b) inorganic surfaces c) both inorganic and organic surfaces d) none of the above

c) both inorganic and organic surfaces

cells communicate and coordinate actions through?

quorum sensing

# **Steps of Biofilm** 1) cellular flagella attach to a)... 2) microcolonies form. Some cells undergo b)... 3) cells secretes a matric of c)... 4) the biofilm matures. Cells communicate by d)... 5) Biofilm dissolves and cells e)...

a) monolayer b) twitching motility c) Extracellular polymeric substances (EPS) d) quorun sensing e) disperse

Bacteria in endospores are dormant and require nutrition or energy **true or false**

false **Endospores are dormant and do not require nutrition or energy**

Bacillus such as (B.anthracis) Clostridium such as (C. botulinum and C. tetani) can create what?

endospores

Which bacteria classification can produce endospores?

Gram positive

the term for making endospores

sporulation

Which of the following would be in BOTH a prokaryotic and eukaryotic cell? a) ribsomes b) mitochondria c) conjugation pilus d) endoplasmic reticulum

A) ribosomes

Which of the following is true of passive diffusion? a) it occurs with the concentration gradient b) it never involves a protein transporter c) it occurs against the concentration gradient d) it always involves a protein transporter

a) it occurs with the concentration gradient

You are investigating the cause of an outbreak of food poisoning. The culprit contains peptidoglycan and lipopolysaccharide. Which of the following organisms could it be? a) staphyloccus aureaus, a gram positive bacterium. b) e. coli, a gram-negative bacterium c) aspergillus fumigatus, a fungi d) any of the above organisms could be the cause

b) e.coli a gram negative bacterium.

Which of the following is a characteristic of a Gram-positive cell wall? a. waxy due to the presence of mycolic acid b. outer membrane with lipopolysaccharide c. thick with several layers of peptidoglycan d. periplasmic space between membrane and peptidoglycan

c. thick with several layers of peptidoglycan