structure of bacteria

Question 1

cell morphology: 6

Answer 1

coccus, spirochete, rod, budding and appendages bacteria, spirillum, filamentous bacteria

Question 2

cell size

Answer 2

surface area to volume ratio - faster uptake of nutrients -more cells per given resource -more cells more mutation -drives evolution

Question 3

difference between phospholipid bilayer in archaea and bacteria

Answer 3

bacteria nd eukarya have ester bond. Archaea have ether bonds

Question 4

membrane and secreted proteins

Answer 4

proteins secreted int periplasm: protein translated in ribosome from mRNA. SecA added to the end of protein and this allows the protein t be secreted into the periplasm Proteins inserted into membrane: proteins translated and signal recognition particle added to the end and this allows it to be inserted into the membrane

Question 5

if the translated protein does not have signal sequence attached to it then the protein will

Answer 5

not be secreted or inserted

Question 6

gram stains distinguish between

Answer 6

gram positive and negative groups

Question 7

gram positive are

Answer 7

violet

Question 8

why are gram positive violet

Answer 8

due to presence of thick layer of peptidoglycan in cell walls

Question 9

gram negative are

Answer 9

red

Question 10

cell wall made up of

Answer 10

peptidoglycan (murein)

Question 11

% of cell wall which is murrain in gram positive and negative bacteria

Answer 11

90% in +ve 10% in -ve/

Question 12

light microscopy

Answer 12

cells can be alive. Diameter of the smallest resolvable object is equal to .51/ numerical aperture. .

Question 13

what is the magnification and resolution of a light microscope using a 10 ocular lens with a typical 10x objective lens and a light source of 50nm

Answer 13

100 and 1um

Question 14

cell survive structures

Answer 14

capsule, biofilms, fimbriae and pili, flagella

Question 15

capsule

Answer 15

polysaccharide or protein or both. Plays a role in pathogenesis and biofilm formation

Question 16

biofilm

Answer 16

the predominant bacterial phenotype in nature and may form on solid substrates in contact with moisture e.g. teeth, on soft tissue and at liquid air interface

Question 17

what allows for the control of growth rate and growth yield to be controlled independently

Answer 17

biofilms–> an keep cells in a certain phase for long periods of time, therefore useful for studying enzymes

Question 18

fimbriae and pili

Answer 18

proteinaceous but can be glycosylated. Plays a role in pathogenesis, biofilms and conjugation–> twitching motility

Question 19

flagella

Answer 19

multimeric protein complex traversing both inner an outer membrane. Helical shaped.

Question 20

flagella structure

Answer 20

helical in shape. Anchored by the MS ring in the inner mem. and the L and P ring in the peptidoglycan and outer membrane.

Question 21

counting bacteria

Answer 21

by either microscopy or by culture

Question 22

outer membrane

Answer 22

second lipid bilayer in Gram negative bacteria. Not just phospholipids as in cytoplasmic membrane. Large polysaccharide component- lipopolysaccharide

Question 23

mature biofims

Answer 23

more of the volume is occupied by the loosely organised glycocalyx matrix (75-95%) than by bacterial cells (5-25%). Because the glycocalyx matrix holds a lot of water, abiofilm- covered surface in gelatinous and slippery

Question 24

secondary colonizers

Answer 24

as well as trapping nutrient molecules,, the glycocalyx net also snares other types of microbial cells through physical restraint nd electrostatic interaction attached to a solid surface

Question 25

biofilm formation- pic

Answer 25

..

Question 26

endospore

Answer 26

An endospore is a dormant, tough, non-reproductive structure produced by a small number of bacteria from the Firmicute family. The primary function of most endospores is to ensure the survival of a bacterium through periods of environmental stress.