Bacterial structure and function

Question 1

5 examples of microorganisms

Answer 1

viruses
bacteria
algae
fungi 
protozoa

Question 2

three points about archae

Answer 2

prokaryotes
no peptidoglycan
often extremophiles

Question 3

3 points about eukaryotes

Answer 3

eukaryotic
if they have cell walls, they dont contain peptifoglycan
not sensitive to traditional antibiotics

Question 4

5 points about bacteria?

Answer 4

prokaryotic
cell walls have peptidoglycan
sensitive to traditional antibiotics
include cyanobacteria, gram positive and gram negative bacteria
include majority of pathogenic microorganisms

Question 5

3 points of bacteria strucutre?

Answer 5

cytoplasmic membrane surrounded by peptidoglycan cell wall and maybe membrane
fluidcytoplasm with nuclear regions
various external structures like a capsule, flagella and pili

Question 6

what are 4 examples of bacteria morphology

Answer 6

straight rod
club shaped rod
branching rod
spore-forming rod

Question 7

what are three bacteria cell arrangements?

Answer 7

division in plane - to form chain
division in two planes- to give tetrad
division in three planes- to give cluster

Question 8

how does cell wall protect bacteria?

Answer 8

protects from osmotic lysis

Question 9

how do penicillin adn lysozome enzymes worl

Answer 9

inhibits cell wall synthesis

attacks peptidoglycan

Question 10

what is peptidoglycan

Answer 10

a thick rigid layer fround in G+ and G_ cells

composed of overlapping lattice of 2 sugars and crosslinked by amino acid bridges

Question 11

how is rigidity determined in peptidoglycan?

Answer 11

amount of peptide cross linking

Question 12

what two sugars are found only in cell walls?

Answer 12

NAG and NAm; side chain attached made of four amino acids forming a cross link

Question 13

explain the basis of crosslinking (3)

Answer 13

peptidogylcan is rigid mesh due to peptide crosslinking
a tetrapide attached to NAM
tetrapeptode is unusal because contains both D and L amino acids

Question 14

4 points about G_ bacteria

Answer 14

outer and inner membrane
in membrane is peptidoglycan
periplasmic space
much more difficult to hit antibiotics

Question 15

3 points about G+

Answer 15

one membrane
thick layer of peptidoglycan
other molecules linked to cell membrane

Question 16

why are G- and G+ important?

Answer 16

diagnostics
virtual tool for diagnosing disease
G+ show darker staining

Question 17

how does gram strain process happen

Answer 17

fix bacteria onto slide
fix crystal violet using iodine
add acetone
strips dye away from outer periplasmic space of only G+ cells

Question 18

what are 5 microorganism classification growth characteristics?

Answer 18

shape
gram stain
atmosphere
spores
biochemical test; genetic/ antigenic

Question 19

3 points about nuceloid

Answer 19

contains singe chromosome
most bacteria have single continous giant circular molecule
supercoiling due to enzyme called DNA gyrase

Question 20

what are the 3 stages of bacteria chromosome replication?

Answer 20

at origin of replication, helicase unwinds to expose single-stranded DNA
primase synthesis ,primers and DNA dependent DNA polymerase synthesises DNA semi-conservative
two idnetical daughter chromosomes are formed

Question 21

what are 4 facts about binary fission?

Answer 21

divide assexually be binary fission where one bacterium split into two
benefit of rapid population expansion but drawback pf binary fission is theres no genetic recombination
no genetic diversity

Question 22

what are the 6 stages of binary fission?

Answer 22

chromosomes replication is initaed at membrane
DNA replication starts at origin
there is extension of cell wall and membrane
septum formation
membrane attachment of chromosomes pulls each daughter chromosome into a new cell
cell seperation; cytokinesis

Question 23

what are 4 other bacterial structures?

Answer 23

spores
capsules
pili
flagella

Question 24

what are endospores

Answer 24

dormant survival structures inly present in G+ organisms, never G-
resistant to high temperatures

Question 25

how do we achieve sterilisation?

Answer 25

kill spores hence autoclaving

Question 26

what are capsules made from

Answer 26

viscous polysaccaride or polypeptide slime

Question 27

how do capsules work

Answer 27

protects bacteria from drying, traps nutrients- enable certain bacteria to adhere to surfaces

Question 28

what are pili

Answer 28

has a shat composed of protein pilin, end of shaft adhesive tip callede lectin whihc binds sugars to host