Prokaryotic cells

Question 1

Thick peptidoglycan cell wall

Gram + or ?

Answer 1

Gram +

Question 2

No outer Membrain

Gram + or -?

Answer 2

Gram +

Question 3

Penicilin provents cross linking chains from forming

Gram + or -?

Answer 3

Gram +

Question 4

Penicilin inhibits enzyme from working

Gram + or -?

Answer 4

Gram +

Question 5

Cell wall synthisis is disrupted

Gram + or -?

Answer 5

Gram +

Question 6

New cells grow abnormaly

Gram + or -?

Answer 6

Gram +

Question 7

Cells burst due to weakened cell wall - Lysis

Gram + or -?

Answer 7

Gram +

Question 8

Thin peptidoglycan cell wall

Gram + or -?

Answer 8

Gram -

Question 9

Peptidoglycan surrounded by outer membrain layer

Gram + or -?

Answer 9

Gram -

Question 10

Antibiotic must cross cell wall to be effective

Gram + or -?

Answer 10

Gram -

Question 11

Ridgid cell wall to prevent exess water access

Gram + or -?

Answer 11

Gram -

Question 12

Cells dont burst

Gram + or -?

Answer 12

Gram -

Question 13

Cells continue to grow

Gram + or -?

Answer 13

Gram -

Question 14

Stains purple

Gram + or -?

Answer 14

Gram +

Question 15

Stains pink

Gram + or -?

Answer 15

Gram -

Question 16

Wich stain dosn’t effect gram - bacteria?

Answer 16

Crystal Violet

Question 17

Why is Safranin able to stain Gram - but not Gram+?

Answer 17

Safranin is smaller than crystal violet and can penitrate the outer membrain layer of gram - to reach the peptidoglycan layer underneeth BUT in gram +, the darker crystal violet stain is too dark for the pink to be seen, but it dose still stain the gram +

Question 18

How dose penicilin work on gram +?

Answer 18

• Penicilin disrupts the cell wall synthisis
• Wich stops an enzyme, that forms cross bridges, from working
• This weakens the short protines they are made of
• Leading to the cells being unable to hold up under osmosis and bursting (lysis)

Question 19

Why dosn’t penicilin work on gram -?

Answer 19

Gram - has an outer cell memebrain that acts as a barier that protects the peptidoglycan from the penicilin.
- this keeps the cell wall strong/ridgid
- prevents the cell from bursting under osmosis

Question 20

Gram staining technique

• Add b——- cultures to microscope slide
• Add C——- V—– stain and rince with lugiol’s iodeen and ethanol
• Add s——- stain and rince with water
• Allow to — and add cover slip before viewing under microscope

Answer 20

• Add bacterial cultures to microscope slide
• Add crystal violet stain and rince with lugiol’s iodeen and ethanol
• Add safranin stain and rince with water
• Allow to dry and add cover slip before viewing under microscope