Which best lists the end products of the light-dependent reactions of photosynthesis?
A. ATP and NADPH
B. $CO _2$ and $H _2 O$
C. ATP, NADPH, and $O _2$
D. $C _6 H _{12} O _6$ and $O _2$
Answer (1)
The question asks for the end products of the light-dependent reactions of photosynthesis.
The light-dependent reactions produce ATP, NADPH, and O 2 .
Comparing with the options, the best match is ATP, NADPH, and O 2 .
Therefore, the answer is A TP , N A D P H , an d O 2 .
Explanation
Understanding the Question The question asks us to identify the end products of the light-dependent reactions of photosynthesis. Photosynthesis is the process by which plants convert light energy into chemical energy in the form of glucose. This process consists of two main stages: the light-dependent reactions and the light-independent reactions (also known as the Calvin cycle).
Identifying the Light-Dependent Reactions The light-dependent reactions occur in the thylakoid membranes of the chloroplasts. In these reactions, light energy is absorbed by chlorophyll and other pigments, which drives the splitting of water molecules ( H 2 O ). This process, called photolysis, releases oxygen ( O 2 ) as a byproduct. The light energy is also used to generate ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate), which are energy-carrying molecules that will be used in the next stage of photosynthesis.
Selecting the Correct Option Based on the description above, the end products of the light-dependent reactions are ATP, NADPH, and O 2 . Let's compare this with the given options:
ATP and NADPH
C O 2 and H 2 O
ATP, NADPH, and O 2
C 6 H 12 O 6 and O 2
The best match is ATP, NADPH, and O 2 .
Final Answer Therefore, the correct answer is ATP, NADPH, and O 2 .
Examples
Understanding the products of photosynthesis is crucial in agriculture. Farmers can optimize growing conditions (light, water) to maximize the efficiency of the light-dependent reactions, leading to higher yields. For example, ensuring adequate light exposure can increase the production of ATP and NADPH, which are essential for the subsequent synthesis of glucose, the plant's primary energy source. This knowledge helps in developing strategies for sustainable and efficient crop production.
