What is photosynthate?

• A. Energy stored as starch in twigs, trunk, and roots for later use
• B. Energy stored as lipids in seeds
• C. Energy stored as ATP in mitochondria
• D. Energy stored as glucose in sap

Answer: (A)

Photosynthate refers to the carbohydrates produced by photosynthesis that the plant uses and moves to other parts. In trees and many plants, a portion of this assimilate is stored as starch in tissues such as twigs, the trunk, and roots so the plant can draw on energy later when photosynthesis isn’t happening or when growth demands more energy than current photosynthesis provides. This storage form lets the plant accumulate energy reserves for future use.

Think of the other options as describing different energy forms or processes. Lipids stored in seeds are a form of reserve, but they’re not the immediate carbohydrate products of photosynthesis. ATP in mitochondria is produced by respiration, not directly stored photosynthate. Glucose in sap isn’t the typical transport or storage form—sap mainly carries sugars like sucrose. The key idea is that photosynthate is carbohydrate produced by photosynthesis, and storing it as starch in storage tissues is a common way plants conserve energy for later.