What is the full form of $ATP$?

In haemoglobin,iron is present in:

In a water molecule,at what angle are the $H - O - H$ bonds connected (in $^\circ$)?

Given below are two statements:
Statement $I$: $A$ protein is imagined as a line,the left end represented by the first amino acid ($N$-terminal) and the right end represented by the last amino acid ($C$-terminal).
Statement $II$: Adult human haemoglobin consists of $4$ subunits (two subunits of $\alpha$ type and two subunits of $\beta$ type).
In the light of the above statements,choose the correct answer from the options given below:

The most common free ion in a cell is:

Identify the substances among the following that contain both glycosidic and peptide bonds in their structure.