diversity + bacteria

Question 1

what is the use of using 16s RNA sequence

Answer 1

visualise differences between different groups of bacteria and then using PCR to sequence and produce phylogenetic tree

Question 2

what are characteristics of the cell membrane

Answer 2

-osmotic barrier
-transport of solutes
-synthesis of wall polymers + lipids
-protein secretion
-respiratory electron transport

Question 3

what are characteristics of the cell wall

Answer 3

-rigid layer
-resists osmotic pressure + determines cell shape
-signals to innate immune system of bacterial presence

Question 4

what colour is produced with a gram +ive stain

Answer 4

purple

Question 5

what colour is produced with a gram -ive stain

Answer 5

pink

Question 6

what 2 bacterial classification do gram +ive/-ive stains result in

Answer 6

-cocci
-rods

Question 7

what is the difference in peptidoglycan in +ive stains

Answer 7

peptidoglycan is thicker

Question 8

what do the terms OM, PG, and CM stand for

Answer 8

OM - outer membrane
PG - peptidoglycan
CM - cell membrane

Question 9

what is peptidoglycan

Answer 9

complex polymer of sugars with side chains of amino acids

Question 10

what role does peptidoglycan have with bacteria

Answer 10

-role in bacterial replication
-target for some antibiotics

Question 11

what are the three parts of lipopolysaccharide (LPS, endotoxin)

Answer 11

-lipid A
-core polysaccharide
-O-polysaccharide

Question 12

what are plasmids capable of

Answer 12

autonomous replication = provide selective advantage

Question 13

what are features of the flagella

Answer 13

-provide mobility
-energy provided by proton motive force

Question 14

what are external structures found on bacteria

Answer 14

pili and fimbriae

Question 15

what are the main differences between pili and fimbriae

Answer 15

-pili longer than fimbriae
-fimbriae more abundant per cell than pili

Question 16

what is a function of fimbriae and an example of it in action

Answer 16

adhesion e.g required for e.coli strains to adhere to urethra to cause UTI

Question 17

what is a function of pili and an example of it in action

Answer 17

twitching motility e.g extension and retraction of pili = move along solid surface

Question 18

what is the sex pilus involved in

Answer 18

DNA transfer in conjugation - longer pili

Question 19

what are features of capsules

Answer 19

-tightly bound to bacterial wall
-can be in both gram +ive/-ive
-contains water => prevents desiccation

Question 20

how are molecules transported through passive transport

Answer 20

–simple diffusion
-facilitated diffusion (require channel or carrier protiens)

Question 21

how is simple diffusion carried out

Answer 21

through membrane with small hydrophobic molecules e.g O2, CO2, ammonia, H2O

Question 22

what does antiport mean

Answer 22

ion and substances move in opposite direction

Question 23

what does symport mean

Answer 23

both move in the same direction

Question 24

what are the 3 types of active transport

Answer 24

-ion coupled transport
-ABC transport
-group translocation

Question 25

what is the role of ABC transporters (ATP-binding cassette)

Answer 25

hydrolysis of ATP drives transport with specific binding proteins

Question 26

what is the role of group translocation

Answer 26

transport and modify the sugar to maintain the concentration gradient