Ch 3 Microscopes and cell structure

Question 1

Capsule

Answer 1

A distinct gelatinous material that surrounds some microorganisms
Called slime layer if its diffuse and irregular
Most are composed of glycocalyx (polysaccharides)

Question 2

Chemotaxis

Answer 2

movement of a cell towards or away from a certain chemical in it’s environment

Question 3

Cytoplasmic membrane

Answer 3

Phospholipid bilayer that surrounds the cell

Question 4

Endospore

Answer 4

A extraordinarily resistant dormant cell produced by some bacteria

Question 5

Flagellum

Answer 5

A structure used for cell movement

Question 6

Gram-negative bacteria

Answer 6

Cell wall with a thin layer of peptidoglycan surrounded by an outer membrane: pink stain

Question 7

Gram-positive bacteria

Answer 7

Cell wall characterized by a thick peptidoglycan layer: stains purple

Question 8

Lipopolysaccharide (LPS)

Answer 8

Molecule that makes up the outer layer of the outer membrane of the Gram-negative bacteria
Endotoxin
A Lipid: portion the body recognizes as a threat
O antigen: made of sugar molecules and identifies certain species

Question 9

Peptidoglycan

Answer 9

Macromolecule that provides strength to the cell wall, found only in bacteria

Question 10

Periplasim

Answer 10

Gel-like layer that fills the region between they cytoplasmic membrane and the outer membrane in the Gram-negative cell

Question 11

Pili

Answer 11

Cell surface that allows it to adhere to certain surfaces

Question 12

Plasmid

Answer 12

Extrachromasomal DNA molecule that replicates independently of the chromosome

Question 13

Ribosome

Answer 13

Structure involved in protein synthesis

Question 14

Transport system

Answer 14

Mechanisms used to transport nutrients and other small molecules across the cytoplasmic membrane

Question 15

Light microscope

Answer 15

Visible light passes through a series of lenses to produce a magnified image.
Easy to use and less expensive
1’000 x

Question 16

Electron Microscopes

Answer 16

Electron beams are used in place of visible light to produce the magnified image
Can magnify up to 100,000x

Question 17

Atomic Force Microscopes

Answer 17

A prob moves in response to even the slightest force between it and the sample
Shows bumps and valleys of the atoms on the surface of the sample

Question 18

Staining

Answer 18

Sample staining: dying the cell on the slide

Negative staining: Coloring the back ground behind the cell

Question 19

Differential staining:

Answer 19

Used to distinguish different groups of bacteria:
Gram staining
Acid-fast staining
Capsule staining
Endospore staining
Flagella staining
Flurescent dyes and taging

Question 20

Shapes of bacteria

Answer 20

Coccus: round
Rod: round and long
Vibro: short curved rod
Spirillum: Short spirlla 
Spirochete: long helical cell

Question 21

Cell Groupings

Answer 21

Chains
Packets: two or more planes, perpendicular
Clusters: several random planes

Question 22

Cell envolope

Answer 22

All the surface layers of a prokaryotic cell

Question 23

Proton Motive Force

Answer 23

Separation of protons and hydroxyl ions across a membrane creates electrochemical gradient across the membrane. The energy is harvested when protons move back into the cell

Question 24

Transport systems

Answer 24

Facilitated: no energy and can only equalize concentration gradient
Active: Uses energy to move against the concentration gradient
Group Translocation: Uses energy and chemically alters substance being moved across the membrane

Question 25

PCN vs. Lysozyme antibiotics

Answer 25

PCN: prevents the cross linking od adjacent glycan chains
Lysozyme: breaks existing bonds that link glycan chain