Asample of ocean water is tested for its bacterial content in a plate count assay. a one-milliliter sample of the water is diluted in a 1: 10 dilution series. 0.1 milliliter of the second dilution tube is plated in a pour plate. after incubation, the plate has 191 colonies, indicating that the original water sample

191000 cells per millilitre

Explanation:

After incubation the plate has 191 colonies. Since each colony grows from a single cell, the plate had 191 cells.

Now only 0.1 millilitre was plated from 1 millilitre of sample hence number of cells in 1 millilitre of sample is 10 * 191 = 1910 cells.

It has been given that this sample is taken from second dilution tube of 1:10 dilution series. So total dilution here has been of 100 times. Hence, original water sample contained 1910 * 100 = 191000 cells per millilitre.

hydroxyl -oh

alcohols, always polar, can form hydrogen bonds with h2o molecules

carboxyl -cooh  

cargoxylic acids, has acidic properties which is a source of hydrogen ions, found in cells in ionized for with a charge of oh-1

carbonyl > co

ketone if within skeleton, aldehyde if group is at the end of skeleton, k & a may be structural isomers, it determines 2 sugars (ketose & aldose)

amino -nh2

amines, acts as a base, it can pick up h+ ions from surrounding solution, ionized with charge of 1+

methyl ch2

addition to rna/dna affects and gene expression

phosphate -opo3 ²⁻

organic phosphates, contributes to negative charge to, molecule that it is a part of, and potential to react with h20

sulfhydryl -sh

thiols, cross-linking stabilize the protein, and it is structure