Plant biochemistry deals with both the chemical and physiological processes which occur within plants. These processes are essential for proper plant functioning and they are all connected. Different reactants and products are necessary for all of these processes to occur and often the products of one reaction are required for a different reaction to take place.
Understanding the mechanisms of respiration and photosynthesis are imperative in plant biochemistry because these processes form the foundation of plant functioning. Respiration depends on photosynthesis to create glucose so that during respiration these molecules can be metabolized and energy can be created. Respiration can either be aerobic or anaerobic in plants, depending on whether oxygen is used, but the overall objective of respiration is the same, to produce energy.
Photosynthesis is comprised of two important and interconnected processes: the light reactions and the dark reactions. Without both of these processes, glucose molecules cannot be made. Furthermore, in different climates, plants have acquired slightly different photosynthetic pathways which allow them to perform photosynthesis optimally in their environments. These pathway differences have to do with water efficiency and the functioning of important enzymes. Plants can be classified as either being C3, C4 or CAM plants:
C3 plants: C3 is the most common photosynthetic pathway. These plants function well in moderate climates, with cool and moist conditions and moderate light intensity.
C4 plants: These plants are better in environments with greater light intensity and higher temperatures compared to C3 plants.
CAM plants: These plants are usually found in arid environments.
Besides these two major processes, other important functions of plants include nitrogen uptake, the role of phytohormones and the role of minerals. Having a firm understanding of how a plant functions chemically and physiologically is essential, especially for applications such as genetic engineering and food production.