Question

why do the biochemical reactions of living things depend on water?
select all that apply
a water must be present for many biochemical reactions to take place.
b water can dissolve many substances.
c water may be a reactant or a product.
d water holds energy needed for many reactions.

Explanation:

• Option a: Many biochemical reactions (like hydrolysis, dehydration synthesis) require water as a medium or reactant, so this is correct.
• Option b: Water is a universal solvent, dissolving many solutes (e.g., ions, polar molecules) needed for reactions, so this is correct.
• Option c: In reactions like photosynthesis (produces water) and hydrolysis (uses water as a reactant), water acts as reactant or product, so this is correct.
• Option d: Water does not hold energy for reactions; energy for reactions comes from chemical bonds of molecules like ATP, so this is incorrect.

Answer:

a. Water must be present for many biochemical reactions to take place.
b. Water can dissolve many substances.
c. Water may be a reactant or a product.