The artificial sweetener $X$ contains a glycosidic linkage and $Y$ contains amide and ester linkages. $X$ and $Y$ respectively are:

Which of the following statements are correct?
a) In maltose,$C-1$ of one $\alpha-D$-glucose is linked to $C-4$ of second $\alpha-D$-glucose.
b) Quaternary structure of protein represents spatial arrangement of two or more polypeptide chains with respect to each other.
c) Nucleotide units in a nucleic acid are joined to each other through a phosphodiester linkage.
d) Abnormally low level of thyroxine leads to hypothyroidism.

During the process of aerobic respiration, $Acetyl \ Co-enzyme \ A$ is formed from which of the following?

The tripeptide is written as Glycyl-Alanyl-Glycine. What is its correct structure?

Which of the following contain $\alpha$-$D$-glucose units?
$a$) Cane sugar
$b$) Milk sugar
$c$) Cellulose
$d$) Amylose

Oxidation of glucose is one of the most important reactions in a living cell. What is the number of $ATP$ molecules generated in cells from one molecule of glucose?