Prokaryotic cells

Question 1

What is the main diff between prokaryotic and eukaryotic cells

Answer 1

Prokaryotic has no membrane-bound nucleus and no membrane-bound organelles

Eukaryotic has membrane-bound nucleus and membrane-bound organelles

Question 2

Structure and function of cell wall

Answer 2

Fully permeable
Main component is peptidoglycan (peptide + sugar)

Function:
Maintains characteristic shape of cell
Prevents cell from bursting

Question 3

Function of cell membrane

Answer 3

Same shit as eukaryotic

Separate cell from environment
Protein anchor
Permeability barrier

Question 4

Structure of cytoplasm

Answer 4

80% water, proteins, carbs, lipids, inorganic ions, low MW compounds

Thick, aqueous, semi-transparent

Contains Nucleoid, Ribosomes and plasmid

Question 4

Nucleoid function?

Answer 4

Carries genetic info for bacteria (contains DNA, RNA)

Question 5

Structure of plasmids?

Answer 5

Small, circular double-stranded DNA molecules that can exist independently of the host chromosome
Can replicate itself independently

Question 6

Structure and function of Pili (Pilus singular)

Answer 6

Structure: Hair-like projections on bacteria (made of proteins)

Function: Transfers genetic material from donor bacterial cells to recipient cells in a process called conjugation

Question 7

Structure and Function of Fimbriae (fimbria singular)

Answer 7

Structure: Short protrusions on surface of bacteria (shorter than pili)

Function: Helps bacteria adhere to host environment
NOT involved in movement

Question 8

Since Fimbriae and Pili are both protrusions, cannot be differentiated in diagrams.

Answer 8

NIL

Question 9

Structure of Ribosomes (again)

Answer 9

2 subunits (large and small)
Consist of protein + RNA

Question 10

Glycocalyx structure + function

Answer 10

Structure: mainly polysaccharides (carbs)
A sticky sugar layer surrounding cell

Functions:
Attachment to surfaces
Protection from engulfment by white blood cells
Protection from harsh environmental conditions
Helps in colonisation

Question 11

Structure and function of Flagella (flagellum singular)

Answer 11

Structure: like a wire at the end of the cell, made of proteins

Function: moves cell in response to a stimuli (towards nutrient-rich regions, light, oxygen-rich areas etc)

Question 12

What IS an endospore

Answer 12

Composed of thick, impermeable spore coat + a dehydrated centre

Question 13

Function of Endospore

Answer 13

Resistant to environmental conditions like heat, radiation and chemicals

its a so-called “seed” of bacteria
germination occurs when endospore is in a favourable environment.