Physiological Processes in Plant

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The study of plant functions and behavior is Plant Physiology and it comprises of all the dynamic processes of growth, reproduction, defence and interaction that are responsible for plants staying alive.

Taking cognizance of the fact that most of these activities or processes take place at the levels of cells, business and organs there is because of the close proximity between the structure and function in plants, also a close proximity between plant anatomy and plant physiology. However within living cells, most of the metabolic activities that takes place are at the molecular level.

Thus we will be discussing some Physiological Processes in Plants, they include;

i. Photosynthesis

ii. Respiration

iii. Transportation in higher plants.

Photosynthesis

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Photosynthesis is the process whereby Green Plants synthesize organic materials or substances from Carbon(iv)oxide and Water this making use of the energy captured from sunlight by the Chlorophyll. At the end Oxygen is released as a waste product.

Materials necessary for Photosynthesis

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i. Water

ii. Light

iii. Carbon(Iv)Oxide

iv. Chloroplast

Temperature, light intensity and carbondioxide are the three main factors affecting Photosynthesis and enough evidence of Photosynthesis is the presence of Starch in a Plant. Testing for starch in a leaf requires four steps;

i. Boiling the leaf for five minutes to kill germs.

ii. Use wate to remove the green color of the leaf by boiling in ethanol.

iii. Rinse the leaf with hot water to soften.

iv. A few drops of iodine solution on the leaf reveals a blue back color which shows that starch is present.

Respiration

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The breaking down of food molecules to release energy is Respiration. This process occurs in the Mitochondria of cells. When energy is released during respiration it is stored in a compound known as ATP(Adenosine Triphosphate). There are two types of Respiration, Aerobic Respiration which is when Oxygen is present in the break down process and Anaerobic Respiration when Oxygen is not present.

The release of energy in respiration is Glycolysis which is the anaerobic break down of glucose without the presence of Oxygen to Pyruvic acid with the release of a small amount of energy.

Differences between Aerobic and Anaerobic Respiration

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i. Oxygen is present for oxidation in Aerobic Respiration while Oxygen is not involved in the process in Anaerobic Respiration.

ii. In Aerobic Respiration the by-product are water and carbondioxide while in Anaerobic Respiration the by-product is alcohol or lactic acid.

iii. In Aerobic Respiration more energy is released while in Anaerobic Respiration the energy released is less.

iv. Aerobic Respiration takes place in the Mitochondria while Anaerobic Respiration occurs in the Cytoplasm.

Transportation in Higher Plants

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Transportation in Higher Plants can be categorized into the following;

Translocation

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When food is transferred from the point where it was manufactured to the storage organs or to other parts of the plant, this process is called Translocation and it occurs in the night. Translocation takes place in the Phloem Tissue. Translocation occurs by the process of diffusion through the cytoplasm. The food is stored in the form of starch when translocated and can be used to produce energy.

Absorption and Transport of Water

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The root hairs of plants absorp water from the soil, thus root hair is surrounded by soil water and soil water with some mineral salts serve as a weak solution. The root hairs comprises of a cytoplasmic membrane which serves as a semi-permeable membrane. There is high osmotic pressure in the cell sap of the root hair which acts as a concentrated solution. Thus water enters into the cell through the process of Osmosis.

When the cell sap of the root hair is diluted, water passes from it to the next cell. This moves it from cells to cells inwardly then it reaches the Xylem Vessels which then conducts it into the stem and into the leaves.

Absorption and Transport of Mineral Salts

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Diffusion is the process through which Mineral Salts in form of ions enter the root hairs of plants. The reason is that there are higher concentration of mineral salts in the soil solution than in the root cells. The ions move from the root hairs to the cells then by diffusion across to the root corterxt to the Xylem Vessels.

However if the quantity of mineral salts in the soil is less than what is in the root then the ions of the mineral salts are drawn into the root via Active Transportation. This when substance moves from a region of lower concentration to a region of higher concentration.

Transpiration

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This is the escape or loss of water from the aerial parts of plants via evaporation. This process occurs through the Stomata. When water is lost as a result of transpiration it is replaced by water in the Xylem vessels. Then more water is absorbed from the soil. This process of replacement and absorption creates a stream like water movement known as Transpiration Pull. It aids in the absorption and transportation of water and mineral salts.

Conclusion

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These are natural occurrences that occur in plants and I am sure we must have learnt a thing or two about the physiological processes of plants. This gives a deep insight on how plants produce and release energy, produce food and make use of resources in its environment to achieve growth.