DDT 13 - Structure and Funciton of Bacteria Cell

Question 1

size range of bacteria

Answer 1

1-10 µm in length

0.2-2µm in diameter

Question 2

3 basic shapes of bacteria

Answer 2

rod shaped -bacillus
round shape - coccus
spiral - spirillus

Question 3

are bacteria eukaryotic or prokaryotic cells and what does that mean

Answer 3

prokaryotic cells

lack membrane enclosed organelles - no nucleus, mitochondria, chloroplasts

Question 4

example of bacillus bacteria

Answer 4

salmonella

Question 5

example of coccus bacteria

Answer 5

micrococcus - found in skin

Question 6

example of spirillus bacteria

Answer 6

sprioplasma

Question 7

what features do ALL bacterium have

Answer 7

cytoplasm
ribosomes
plasma membrane
nucleoid containing DNA

Question 8

Describe cytoplasm in bacteria and its function

Answer 8

dense and contains ribosomes and storage granules that hold glycogen, lipid or phosphate compounds

Question 9

Describe nucleoid in bacteria

Answer 9

bacteria contain a single, circular, double-helical strand of DNA containing between

Question 10

how many genes are in nucleoid in DNA

Answer 10

3,000 - 6,000 genes within the cytoplasm.

Question 11

Describe plasmid and its function

Answer 11

small circular, double stranded DNA molecule

Carries genes separate from the main DNA of cell, usually genes that are of a selective benefit to the bacterium

Question 12

what features of the bacteria are similar to the human and what are different

Answer 12

ribosomes - same 2 subunits that makeup ribosomes - contain protein and RNA
different subunit composition
Like humans - DNA are tightly packed but don’t contain histones

Question 13

how does one resistant bacteria transfer its resistance to sensitive bacteria

Answer 13

send copy of plasmid through conjugation bridge
Resistant bacterium is in close contact with sensitive bacterium
copy of plasmid in resistant bacterium is made and conjugation bridge is formed
Plasmid copy is transferred through conjugation bridge

Question 14

describe capsule and its function in bacteria

Answer 14

thick sticky gelatinous layer made of polysaccharides
prevent phagocytosis
More difficult for macrophages to undergo phagocytosis because its sticky and to stimulate an immune response

Question 15

describe flagellum and its function

Answer 15

anchored through all layers of bacteria by protein rings
3 parts - basal body, hook - propeller allows filament to move/rotate, filament
allow movement

Question 16

describe pili

Answer 16

hair like appendage
ordinary pili - clump bacteria together
sex pili - transfer genetic info

Question 17

2 types of bacteria cell walls

Answer 17

gram positive

gram negative

Question 18

describe gram positive cell wall

Answer 18

peptidoglycan - Think|
/
plasma membrane|

Question 19

describe gram negative cell wall

Answer 19

thicker outer membrane
peptidoglycan
plasma membrane

Question 20

dyes and stains used to test cell wall type of bacteria

Answer 20

crystal violet
iodine
alcohol
safranin

Question 21

describe how penicillin works against gram positive bacteria

Answer 21

+ive depends on thick layer
penicillin destroys layer - inhibits enzyme involved in peptidoglycan synthesis – Gram positive bacteria more susceptible

Question 22

what colour does Gram positive bacteria go

Answer 22

purple

Question 23

what colour does Gram negative bacteria go

Answer 23

pink

Question 24

function of endospores

Answer 24

bacteria in dormant state

will activate when conditions are favourable to grow and multiply

Question 25

when do endospores form and how do they form

Answer 25

in unfavourable condition s | plasma membrane then 2 spore septums surround endospores

Question 26

example of endospore

Answer 26

tetanus

Question 27

binary fission

Answer 27

one bacterial genome duplicate genetic material septum forms between genetic info and clone cells pinch in 2 and separate

Question 28

how long can bacteria reproduce

Answer 28

in 20 minutes

Question 29

3 types of bacteria DNA exchange

Answer 29

Transformation Conjugation Transduction

Question 30

how does bacteria transfer DNA via transformation

Answer 30

Fragments of DNA are taken in after the disruption of another cell.

Question 31

how does bacteria transfer DNA via conjugation

Answer 31

Two cells exchange genetic material via a sex pilus. conjugation pilus form cells come in contact w/ each other one strand of plasmid move to sensitive cell both donor and recipient form complementary strand of plasmid to be F+

Question 32

how does bacteria transfer DNA via transduction/horizontal gene transfer

Answer 32

Genes are carried from one cell to another by a virus called a bacteriophage DNA of phage/virus penetrate bacteria cell phage DNA can integrate w/ host's DNA = prophage becomes lytic - DNA is degraded and new phages are made cell wall is ruptured - phages ready in penetrate other bacteria

Question 33

detailed recount of transformation in bacteria

Answer 33

uptake of DNA fragments or plasmid from environment from dead bacteria in plasmid usually just stable transformation of plasmid in DNA fragments - it can be unsuccessful and degrade