Nutrition

Atropa belladonna is a plant which means it is autotrophic. If you break down this word "auto" means "self" and "trophos" means "feed". Hence the word autotrophic means self-feeding. Belladonna, along with other plants, takes carbon dioxide and other inorganic materials from the environment and produces organic materials. The plant goes through photosynthesis, which is a process to provide itself with nutrients. Plants are the ultimate source of organic compounds and food for other organisms. Plants require very few actual nutrients to survive. They require water and a few mineral from the soil, as well as the carbon dioxide mentioned previously. Water is transported in belladonna. and other plants, via the xylem. These cells transport the water up to the leaves. Transpiration, along with the properties of water like cohesion and adhesion allow the water to be pulled up the xylem to the leaves.

The site of photosynthesis in the belladonna plant, as well as other plants, is the chloroplasts. The chloroplasts are everywhere in the plant that has a green color. This is because the chloroplasts contain a green pigment known as chlorophyll. The main site of these chloroplasts is in the mesophyll, which is the tissue inside of the leaf. It is not surprising then that the majority of photosynthesis occurs in the leaves of plants. The chloroplast is an organelle that has two membranes which enclose the stroma, the fluid inside the chloroplast, and the thylakoids. The thylakoids are membrane sacs which actually contain the pigment chlorophyll.

Photosynthesis as a process is related to cellular respiration. Cellular respiration is the process by which energy is obtained from organic compounds. Plants actually go through both of these processes, unlike us who only do respiration. Photosynthesis and cellular respiration are redox reactions. The process of cellular respiration involves a release in energy when sugar is broken down and electrons go down an electron transport chain synthesizing ATP (Adenosine Tri-phosphate) which is used for energy. Oxygen is used at the end of this transport chain as the final electron acceptor. Photosynthesis then is the reverse of this process. Water is split and the electrons and hydrogen ions along with the carbon dioxide from the atmosphere are reduced to sugars. This process requires an input of energy, which the plant utilizes the sun for. Therefore plants use photosynthesis to make sugars which then in turn they either use for energy themselves or they provide energy to other organisms when the organisms consume them. The sugar is transported in belladonna and other plants via the phloem. These cells use a number of sugar sources, which are generally the leaves of the plant, and sugar sinks, which generally are the roots of the plant to allow the movement of sugar throughout the entire plant. The sugar moves from the more concentrated source to the less concentrated sink. Sugar is stored in plants in starch molecules.

The process of photosynthesis has two steps; the light reactions and the Calvin Cycle. The light reactions convert the energy from the sun into chemical energy which in turn splits water molecules. The splitting of these water molecules provides a source of electrons and hydrogen ions and also gives off oxygen as a byproduct which other organisms like us use to breathe. These electrons are then carried by an electron acceptor called NADP+ which is reduced to NADPH with the addition of the electrons. ATP is also generated by the light reactions. The Calvin cycle starts with the carbon dioxide from the atmosphere. This first step is known as carbon fixation, during which the carbon is turned into organic compounds. Then electrons are added and the fixed carbon is reduced to carbohydrates or sugars. The electrons from NADPH were used to reduce the carbon and the ATP was used as energy to fuel the process.

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