LESSON-2-Cell-Organelles-and-Their-Functions.pptx

and Their Functions At the end of this lesson, you are expected to: 1. Identify and describe the structure and functions of the different parts of the cell. 2. Compare the structure of plant, animal and bacterial cell. 3. Appreciate how cellular structures play a vital role in body...

and Their Functions At the end of this lesson, you are expected to: 1. Identify and describe the structure and functions of the different parts of the cell. 2. Compare the structure of plant, animal and bacterial cell. 3. Appreciate how cellular structures play a vital role in body functions. The inventions of microscopes have opened up a whole new dimensions in science. What is a cell? How do these cells look and how they function? What processes take place in cells? Onion cells as seen under a microscope Cell Organelles Cell and Organelles and Their Their Functions Functions Two Major Types of Cell Types of Cells  Extremely delicate, thin, elastic, living and semi- Cell Membrane permeable membrane. Made up of two layers of lipid molecules in which ( Plasma protein molecules are floating. Can be observed under an electron microscope only. Membrane ) Functions: Maintains shape and size of the cell · the boundary between the cell and its external environment; and · as a structure that controls the movement of substances in and out of the cell. It is a semipermeable membrane, that allows the entry of some substances, such as water and prevents the entry of others. Protoplasm and Its Organelles The plasma or cell membrane Cytoplasm and Karyoplasm (Nucleoplasm) encloses a mass of jellylike material called protoplasm. If a nucleus is present in a c ell, the protoplasm is differentiated into two: The protoplasm is a colorless or somewhat grayish, translucent, (1) cytoplasm, where the protoplasm is lying viscous substance that is outside the nucleus; and capable of flowing. (2)karyoplasm or nucleoplasm, the protoplasm It is a colloid, can change its inside the nucleus. state from a semisolid gel to a semiliquid solution. Its texture also varies. It is composed of 20 % carbon, 10 % (Powerhouses of the Cell)  Ribosomes (Protein Factories of the Cell) Ribosomes are small granular structures made up of RNA and proteins. The RNA found in ribosomes is produced in the nucleus and enters the cytoplasm through the nuclear pores. Function: Involved in the production of proteins in a process called protein synthesis. (Manufacturers and Shippers of the Cell) (Packaging Counters of the Cell) ( Storage Tanks of the Cell ) (Suicide Bags of the Cell) Centrosome and Centrioles (Helpers in Cell Division) ( Control Center of the Cell ) (Framework of the Cell) Specialized Structures in Cells Plant and animal cells may be similar in many of their features. Somehow, due to complexity in structures and also because of Cell Wall physiological reasons, some Plastids – organelles are found in plant cells Chromoplasts and but are not found in animal cells. leucoplasts Do you know what these structures are?