Answer:
I believe that it would be copper because copper is all of those things.
Explanation:
Biuret reagent will indicate the presence of protein in a given sample. It is also known as the Piotrowski's test. This reagent consists of copper (II) sulfate and sodium hydroxide. It detects peptide bonds by the reaction of the copper ions in an alkaline solution. The copper ions would form violet colored complexes when peptide is present in the solution. From this test, concentration can be calculated since the intensity of the color depends on the amount of peptide bonds and according to the Beer-Lambert law concentration and the absorption of light is proportional. The concentration is calculated by a spectrophotometric technique at a wavelength of 540 nm.
5 is 2 I’m not sure about 4 though....
Answer : The amount of heat needed is, 1188 J
Explanation :
Formula used :

where,
q = heat needed = ?
m = mass of copper = 55 g
c = specific heat capacity of copper = 
= initial temperature = 
= final temperature = 
Now put all the given values in the above formula, we get:


Thus, the amount of heat needed is, 1188 J
Answer:
The correct option is: c. phospholipid
Explanation:
Phospholipids, also known as glycerophospholipids, are the derivatives of fatty acids which is a major structural component of the cell membranes.
Phospholipid is the class of lipids that is composed of a <u>glycerol molecule that forms ester bonds with the two long-chain fatty acids and one phosphate group.</u>
<u>Therefore, Molecule A is a </u><u>phospholipid.</u>