Lab 15: Effect of pH on Bacterial Growth

Question 1

a too acidic or too alkaline pH causes…

Answer 1

irreversible protein denaturation and cell death

Question 2

define an acidophile

Answer 2

organism with the optimal growth range of pH 5.5 or below

Question 3

define a neutrophile

Answer 3

pH 5.5-8

Question 4

define an alkaliphile

Answer 4

organism with an optimal growth range of pH greater than 8

Question 5

which organisms in the experiment were acidophiles?

Answer 5

yeast

Question 6

which organisms in the experiment were neutrophiles

Answer 6

S. epi and E. coli

Question 7

which organisms in the experiment were classified as alkaliphiles?

Answer 7

B. meg

Question 8

by what mechanism does pH affect bacterial growth?

Answer 8

H+ concentration affects proteins and charged molecules in the cell by denaturing protein structure and changing the solubility of charged molecules

Question 9

what type of organisms would grow best in humans?

Answer 9

neutrophiles b/c our body in most places has a pH of 7.4