Nutrition

Photosynthesis

Plants are actually a phenomenal organism. To acquire nutrients and energy, humans have to consume other organisms. However, plants, like the common foxglove, can create their own food by using sunlight to power the synthesis of organic substances. This makes them autotrophs, which means "self-feeder." The only nutrients that they need are water, minerals that the obtain from the soil, and carbon dioxide that they obtain from the air. During photosynthesis, plants convert light energy from the sun, to chemical energy of food. The site where this complex process occurs are chloroplasts, which contain chlorophyll. This chlorophyll is what is responsible for the green pigment in plants.  Go to these to learn about some other extraordinary plants Hoodia gordonii, Hypericum perforatum, and Pongamia pinnata.

Photosynthesis can be be demonstrated by this simple equation:
6CO2 + 6H2O + ---------------> C6H12O6 + 6CO2

In other words, six carbon dioxide molecules plus six water molecules plus sunlight creates a molecule of glucose as well as the oxygen that the plant gives off.

 

However, how does this process happen? Basically there are two separate processes that occur during photosynthesis with many reactants, intermediates, and products. The first process is the Light Dependent Reactions. During this reaction, light energy is used to split water, which provide electrons and protons, and releases oxygen as a by product. The light is then absorbed by the chlorophyll. It is here where the two high energy compounds ATP and NADPH are made by transferring the electrons and hydrogen ions from the water to the electron acceptors, ADP and NADP+. The next process is the Calvin Cycle, also referred to as the Carbon Dioxide Fixation Cycle. During this cycle, carbon from the atmosphere is fixed, meaning it is incorporated with other organic molecules that are already in the chloroplast. Then, electrons from ATP and NADPH are added to  reduce the fixed carbon into carbohydrate. The final products of this process are sugars (carbohydrates) as well as other organic compounds. Furthermore, these two processes are dependent on each other. Below is a illustration of these processes.

 

 

Resource Acquisition and Transportation

Another question that might arise after reading about how plants make their food is how plants transport the food they just made and how do they acquire and transport water and other nutrients. A plant's roots are responsible for acquiring water from the soil as well as other resources like nitrogen and phosphorus. Then, the resources are transported to other parts of the plant using phloem and the water is transported to the rest of the plant using xylem. The food that the plants created with photosynthesis is also transported to the rest of the plant by the phloem. This process is called translocation.

Next to learn more about how Digitalis purpurea reproduce go to Reproduction.