Final answer:
When tea is brewed in hot water, both tannins and caffeine, which are soluble in water, are removed from the tea leaves. Cellulose is not soluble and thus remains in the leaves, while sodium bicarbonate is generally not present in tea leaves. Option B,D are correct.
Step-by-step explanation:
The student is asking about what compounds are removed when tea is brewed in hot water. Specifically, they are inquiring about the presence of cellulose, tannins, glucose, caffeine, and sodium bicarbonate. In the context of tea brewing, it is the tannins and caffeine that are most significantly extracted into the water. Cellulose is not water-soluble, so it remains largely within the leaves.
Glucose might dissolve if it's present in the leaves, but it's not a major extractable component. Sodium bicarbonate is not typically present in tea leaves; it may be added to some types of processed teas for taste or to neutralize acidity, but it is not extracted from the leaves themselves.
Relating to the extraction of caffeine, which is similar between tea and coffee, it is notable that caffeine is a somewhat polar molecule that dissolves well in water. The process of hot water brewing will, therefore, remove caffeine from the tea leaves. The same process also removes the tannins which can affect the bitterness and astringency of the tea.