Plant Anatomy Lecture 3 PDF

# Plant Anatomy ## Lecture 3: Plant Anatomy ### Dr. Mohamed Awes Badry - Assistant Professor of Plant Taxonomy - Faculty of Science - South Valley University **11/12/2024** ## College Vision - Excellence in basic science education and scientific research to contribute to sustainable developmen...

# Plant Anatomy ## Lecture 3: Plant Anatomy ### Dr. Mohamed Awes Badry - Assistant Professor of Plant Taxonomy - Faculty of Science - South Valley University **11/12/2024** ## College Vision - Excellence in basic science education and scientific research to contribute to sustainable development. ## College Mission - To provide distinguished education in the fields of basic sciences and the production of applied scientific research to contribute to sustainable development by preparing distinguished graduates according to the national academic standards, developing skills and capabilities of human resources, and providing community and environmental services that meet the aspirations of the South Valley community, and building effective community partnerships. ## Plant Cell Composition **Protoplast** - **Living Contents:** - Vacuoles - Cytoplasm - Nucleus - Nuclear Membrane - Nucleolus - Chromatin Network - Cell Organelles - Plastids - Mitochondria - Golgi Bodies - Ribosomes - Other Organelles - **Non-living Contents:** - Cell Wall - Starch Grains - Crystals - Oils and Fats - Pigments and Materials - Other Materials **Cytoplasm** - Consists of: - Cytoplasm - Plasma Membranes **Non-protoplasmic Components** - **Non-living contents of the cell:** - Vacuoles - Other components ## The Vacuole - In the cytoplasm of mature plant cells, there is one or more vacuoles called the vacuole. - It is filled with an aqueous solution called the cell sap. - The cell sap is about 98% water and contains many other dissolved or colloidal substances. **Formation of the Vacuole** 1. Vacuoles appear in meristematic cells as small droplets scattered throughout the cytoplasm. 2. As the cell matures and increases in size, these vacuoles grow, fuse together and fill with cell sap. 3. The cell sap pushes the cytoplasm to the cell wall forming a thin layer lining the cell. ## Other Non-living Components of the Cell - These are byproducts of metabolism and appear at different times in the cell’s life. - They are either stored products or secretions produced as a result of the cell's activity. ### Carbohydrates 1. *Dissolved carbohydrates:* - Glucose and fructose, monosaccharides found in the cell sap of most plants. - Sucrose (cane sugar), a disaccharide, found abundantly in the cell sap of beet root and sugarcane stems. - Inulin, a polysaccharide, which hydrolyzes to fructose. It is found in few plants. - Other sugars, such as dextrin, mannitol and pentosans. 2. *Undissolved carbohydrates:* - Starch granules, the most important form of stored carbohydrates, are found in chloroplasts and colorless plastids. - Under the microscope, a starch granule appears as a series of layers with different densities. - They are deposited around a central point called the hilum. The hilum may be distinct in potato starch granules, wheat grains and legume seeds. - It may be central or eccentric based on its position in the starch granule. - It may be simple or compound based on the number of hila. - The starch granules are not soluble in cold water, but they give a blue color with iodine solution. - Starch granule shapes vary between species. ## Starch Granules - Different types of starch granules: - Simple - Half-compound - Compound - Branched ## Aleurone Grains - The sap of some seeds rich in fats, such as castor seeds, contains dissolved proteins. - As the seeds mature and dry, these proteins form what are called aleurone grains. - Under the microscope, aleurone grains appear surrounded by a membrane containing a quantity of uncrystallized proteins which contain one or more crystallized protein bodies. - A large, faceted crystalline body called a crystalloid is made of proteins. - A smaller, usually rounded body called a globoid is formed of proteins combined with phosphates. ## Calcium Oxalate Crystals - These are found in the cell sap in different forms, such as: - Solitary crystals in the form of rhombuses or prisms, in the sap of the sycamore stalk. - Star-shaped crystals called druses in the sap of the tilia stalk. - Acicular crystals called raphides, as seen in the stalk of dracaena, where the crystals, which have the same length, are stacked up in a parallel bundle. ## Calcium Carbonate - - Its main form is the cystolith, which is found in the cuticle cells of the rubber fig plant. - - Calcium carbonate crystals are deposited around a cellulose neck that hangs down from the top of the cell. - The neck grows, forms a cluster, grows into a large cluster that fills the cell. - The cystolith can be detected by adding dilute hydrochloric acid, which dissolves it and releases carbon dioxide. ## Cystolith - Calcium Carbonate is referred to as a cystolith. - The image shows a drawing of a cystolith. ### Other Non-living Components of the Cell 1. *Anthocyanins:* These are pigments that are dissolved in the cell sap. They give the rich colors of the flowers in many species, as well as some other plant organs like the roots of red beets. 2. *Glycosides:* Glycoside molecules consist of a sugar combined with another non-sugar component. 3. *Mucilages:* These are found in the cell sap in some plants, giving it a viscous texture. These substances do not dissolve in water but absorb it to increase in size. They are not soluble in alcohol either. 4. *Tannins:* These are complex compounds with many phenolic groups. 5. *Alkaloids:* These are nitrogenous compounds that are found in many species and are widely used for medicinal purposes. 6. *Latex:* This is a secretion produced by some plants. Latex is a mixture of resins, gums, carbohydrates, and other substances. 7. *Fats and Oils* ## Conclusion - Plant Anatomy is an important field of study. - It helps us understand the structure of plants and how they function. - This understanding can be used to improve plant growth, development and production. ## Thanks for listening!