Many bacteria cannot easily be cultured from their natural habitat. Usually that is because those cells normally obtain a necessary metabolite from a host organism (or other member of the microbial community) and can no longer synthesize that requirement for themselves. Examples of such growth factors include all of the following except.

d. nicotinamide adenine dinucleotide (NAD) and derivatives.

Explanation:

a. amino acids (such as cysteine and proline)

b. vitamins (such as riboflavin and thiamine)

c. Adenosine triphosphate

d. nicotinamide adenine dinucleotide (NAD) and derivatives.

Growth factors of bacteria are compounds that are important for the growth of bacteria but which cannot be synthesized by the bacteria themselves. Without these compounds, the growth of bacteria would be limited or they will not even grow at all.

These compounds which are usually organic in nature include purine and pyrimidine nucleotides, vitamins, amino acids, and hormone-like peptides.

From the options, only option d does not fall among the growth factors required by bacteria.

Hence, the correct option is d.

a neutral ph of 7 and normal organism temperature is needed for a certain enzyme to be effective.  

what would happen to the enzyme if the ph and/or temperature fluctuate greatly from the norm?  

a.the enzyme’s hydrogen bonds will break.  

b.the activation energy will increase.  

c.more product will be formed.

d.the ideal temperature and ph for the enzyme function will decrease.