Non-Membranous Organelles 2024 PDF

Physical therapy dr. manal m. sayed 1 dr. manal m. sayed 2 The cell organelles II Dr. Manal M. Sayed  The non- membranous organelles dr. manal m. sayed 4  1-Ribosomes: Ribosomes...

Physical therapy dr. manal m. sayed 1 dr. manal m. sayed 2 The cell organelles II Dr. Manal M. Sayed  The non- membranous organelles dr. manal m. sayed 4  1-Ribosomes: Ribosomes appear as small particles 15-20 nanometer (nm) in size. Agenda Types: 1. Attached ribosomes: Ribosomes which are attached to endoplasmic reticulum (rER) and are involved in the formation of secretory proteins. 2. Free ribosomes: Ribosomes which are present freely in the cytoplasm and are concerned with the formation of cytoplasmic proteins. dr. manal m. sayed 5  Structure: Ribosomes are intensely basophilic. Chemically, ribosomes are composed of ribosomal RNA and proteins. Each ribosome is formed of two subunits, a small and a large one both formed in the nucleolus. dr. manal m. sayed 6 6  2-Centrosome Agendaorganoids. Centrosome is one of the non-membranous Structure: Spherical pale area near the nucleus composed of two cylindrical rodlets called the centrioles surrounded by a pale area called the centrosphere. E.M: centrioles are formed of microtubules. The centrioles are formed of microtubules (9 Peripheral triplets microtubules). dr. manal m. sayed 7  Function: 1. It acts as a center for the formation of mitotic spindle during cell division. 2. It serves as the basal body for cilia. dr. manal m. sayed 8 8  3-Cytoskeleton It is formed of: a- Microtubules b- Microfilaments c- Intermediate filaments Functions: 1- Maintain cell shape. 2- Stabilizes cell attachments. 3- Plays a role in cell motility. 4. Plays a role in cell division.  1. Microtubules Agenda Structure: They are rigid thin tubular structures about 25 nm in diameter. The wall of the microtubule is composed of a fixed number of globular units formed of a protein called tubulin. dr. manal m. sayed 10  Function: 1-Microtubules determine cell shape. 2- Intercellular transport. 3-They become highly organized to form mitotic spindle of cell division, centrioles, basal bodies and axoneme of cilia. dr. manal m. sayed 11 11  2. Microfilaments Structure: They are very Agenda thin structures reaching about 5 nm in diameter formed of actin molecules. Function: They are involved in cellular movement, and cellular contraction as in muscle cells. dr. manal m. sayed 12  Agenda 3. Intermediate filaments Structure: They are about 10 nm in thickness. There are many types of intermediate filaments depending on their chemical composition. They provide physical support and stability to cells and tissues. dr. manal m. sayed 13 dr. manal m. sayed 14  CYTOPLASMIC INCLUSIONS: Cytoplasmic inclusions are substances present Agendain the cytoplasm as result of accumulation of cell products and are not involved in the cellular activities. There are three types of inclusions: A) Stored food, e.g., glycogen and fat. B) Pigments, e.g., melanin and hemoglobin. C) Crystals. dr. manal m. sayed 15  A) Stored food: Only glycogen and fat can be stored in Agendain the liver animal cells. Glycogen is stored in large amounts and muscle cells. With the LM: glycogen can be localized in cells after staining with PAS. Fat is stored in special types of cells known as fat cells or adipocyte. Fat is stained with Sudan black stain. dr. manal m. sayed 16 dr. manal sayed 17  B) Pigments: Pigments may get into cellsAgenda from outside the body and are therefore known as exogenous pigments or may be formed inside cells and in this case, they are known as endogenous pigments. Exogenous pigments: The most important are carotenoid pigments which enter the body with food. Other exogenous pigments such as dust, and tattoo colors. dr. manal m. sayed 18  Endogenous pigments: The following are examples of endogenous pigments Agenda 1. Hemoglobin: It is the most important pigment and beside its importance in respiration, it gives the skin its red color. 2. Hemosiderin: It results after the breakdown of hemoglobin. 3. Melanin pigment in the skin, hair and iris of the eye. 4. Lipofuscin pigment. (Residual body) dr. manal m. sayed 19  Agenda Melanin pigment dr. manal m. sayed 20  Self- exam dr. manal m. sayed 21 Choose the correct answer: 1.Which of these organelles are formed of two subunits? a) Lysosomes. b)Mitochondria c) Centrosomes d)Ribosomes 2. Which of these organelles acts as a center for the formation of mitotic spindle? a) Lysosomes. b)Mitochondria c) Centrosomes d)Ribosomes dr. manal m. sayed 22 3. Which of these structures are not a part of cytoskeleton? a) Microtubules. b)Myosin filaments. c) Actin filaments. d)Intermediate filaments. 4. In which organs the glycogen are present in large amount? a) Liver and pancreas. b)Muscles and liver. c) Brain and liver. d)Pancreas and brain. dr. manal m. sayed 23 5. Which of these are not endogenous pigments? a) Hemoglobin. b)Melanin. c) Lipofuscin pigment.. d)Tattoo. Enumerate a) Components of cytoskeleton. b) Functions of cytoskeleton. c) Types of ribosomes. d) Types of cell inclusions. e) Types of pigments. dr. manal m. sayed 24 The End Thank you DR. MANAL M. SAYED