I am a 12th grader in India. I have understood basic theory on biomolecules. I know about carbohydates (and structures of important saccharides) and $\alpha$-amino acids, proteins, and peptides.
This is a section given in my book:
I understand what is the meaning of "D"-glucose, and also how to identify the functional group. But, notice the last column in this table. I don't understand what they mean by the "typical nature" in each case.
I searched the net but couldn't find anything. Is my book using obsolete/unknown terminology for an existing concept? What is it? Please tell. Thank you!