Outline the subsequent use and storage of the carbohydrates made in photosynthesis, limited to: (a) starch as an energy store (b) cellulose to build cell walls (c) glucose used in respiration to provide energy (d) sucrose for transport through the plant

Sourav PanNovember 2, 2024

Answered

The carbohydrates produced during photosynthesis serve various essential functions in plants, including energy storage, structural support, and energy provision. Here’s an outline of the subsequent use and storage of these carbohydrates, specifically focusing on starch, cellulose, glucose, and sucrose.

Subsequent Use and Storage of Carbohydrates Made in Photosynthesis

(a) Starch as an Energy Store

• Storage Form: Starch is the primary storage carbohydrate in plants. It is a polysaccharide composed of long chains of glucose units.
• Function: Starch serves as an energy reserve that can be broken down into glucose when needed. This is particularly important during periods of low photosynthetic activity (e.g., at night or during winter).
• Location: Starch is stored in various plant tissues, including roots (e.g., potatoes), stems, and seeds (e.g., grains).

(b) Cellulose to Build Cell Walls

• Structural Role: Cellulose is a polysaccharide made up of glucose units linked together in a linear fashion. It is the main component of plant cell walls.
• Function: Cellulose provides structural support and rigidity to plant cells, helping maintain their shape and integrity. This is crucial for the overall stability of the plant.
• Resistance to Degradation: The strong hydrogen bonds between cellulose molecules create a rigid structure that is resistant to degradation, making it essential for plant strength.

(c) Glucose Used in Respiration to Provide Energy

• Immediate Energy Source: Glucose produced during photosynthesis can be directly used by plant cells in cellular respiration to generate ATP (adenosine triphosphate), which provides energy for various cellular processes.
• Respiration Process: In cellular respiration, glucose is broken down in the presence of oxygen to produce carbon dioxide, water, and energy (ATP). This process occurs in mitochondria and is vital for growth, development, and maintenance of cellular functions.
• Energy Utilization: The ATP generated from glucose respiration powers activities such as nutrient uptake, cell division, and synthesis of biomolecules.

(d) Sucrose for Transport Through the Plant

• Transport Form: Sucrose is a disaccharide composed of one glucose molecule and one fructose molecule. It serves as the main form of sugar transported throughout the plant.
• Function: Sucrose is synthesized in the leaves during photosynthesis and then transported via the phloem to other parts of the plant where it can be used or stored.
• Versatility: Sucrose can be readily converted back into glucose or fructose when needed for energy or metabolic processes. It also plays a role in providing energy to growing tissues such as roots, fruits, and developing leaves.