Prokaryotic cell structure

Question 1

what’s included in the prokaryotic cell structure?

Answer 1

Ribosomes
(Cilium)
Cell membrane
DNA (nucleoid)
Cytoplasm

Question 2

describe the plasma membrane

Answer 2

Proteins embedded in 2D fluid

Lipids provide the scaffold, proteins provide functions

Question 3

which are the pre dominant lipids?

Answer 3

Saccarolipids: Lipid A

Glycerophospholipids: PE, PG, CL

Glycerolipid: DGDG

Question 4

what kind of membrane transport are there?

Answer 4

Passive transport: Facilitated diffusion

Active transporters: energised by ATP or proton motive force (uni, sym, anti)

Group translocation

Question 5

there are two types of cell walls - describe these

Answer 5

Gram + : thick cell wall (peptidoglycan), thin plasma membrane (1 membrane, thick cell wall)

Gram - : plasma membrane, thin cell wall (peptidoglycan), outer membrane (2 membranes, thin cell wall)

Question 6

what does peptidoglycan consist of?

Answer 6

2 sugars (glycan) + peptides (4 or 5)

Question 7

describe the peptidoglycan in gram + bacteria

Answer 7

forms tightly interconnected meshwork, 3D structure

Question 8

describe the peptidoglycan in gram - bacteria

Answer 8

2D structure, cross links, fewer connections

Outer membrane is made of LPS (lipopoly saccharide), proteins formed by beta sheets
Inner membrane proteins formed by alfa helix

Question 9

describe teichoic acids

Answer 9

only in gram +, modifies surface charge, provide flexibility, can determine cell shape

Question 10

describe the gram - flagella

Answer 10

energised through proton gradient across the inner membrane

Question 11

describe the gram + flagella

Answer 11

same overall structure as gram -. Supporting structures crossing the peptidoglycan and outer membrane are not required

Question 12

what is a fimbriae (pili)?

Answer 12

smaller, thinner & simpler than flagella, often involved in cell attachment.

Bacterial conjugation: bacterial pili involved in the transfer of genetic material between bacterial cells.

Question 13

what kind of lipid proteins are most common?

Answer 13

glycerophospholipids: PE, PG, CL

Question 14

outer membrane proteins are formed by ..?

Answer 14

beta sheets

Question 15

inner membrane proteins are formed by …?

Answer 15

alfa helixes

Question 16

what are the two types of bacterial DNA?

Answer 16

chromosomal DNA & plasmid DNA

Question 17

What are inclusions?

Answer 17

energy & carbon storage

Question 18

How do bacteria fit their
genome into the cell?

Answer 18

supercoiling

Question 19

what is the periplasm?

Answer 19

aqueous space between inner & outer membrane (high protein)

Question 20

what’s an s-layer?

Answer 20

cell surrounding layer, proteins

Question 21

what’s a capsule?

Answer 21

surrounding layer, proteins/polysaccharides, important for biofilm formation

Question 22

what’s a hami?

Answer 22

only in archeae. mostly used for attachments –> surface / cell-cell. common in biofilms

Question 23

what’s the archaeal flagella driven by?

Answer 23

ATP hydrolysis