The Cell & Cell Membrane 2025 PDF

Dr. Al Gammal  Abdul Rahman Al Gammal Professor of Histology & Cell Biology Faculty of Medicine Zagazig University Faculty of Physical Therapy Department of Basic science BIOLOGY  OBJECTIVES Cell biology is the science which deals with studying of...

Dr. Al Gammal  Abdul Rahman Al Gammal Professor of Histology & Cell Biology Faculty of Medicine Zagazig University Faculty of Physical Therapy Department of Basic science BIOLOGY  OBJECTIVES Cell biology is the science which deals with studying of Normal structure of the cell (structural, functional unit of the body) Normal behavior & function of different cell components Types of nucleic acids, chromosomal structure & types Cell cycle & how cells proliferate & differentiate Different types & clinical uses of stem cells Dr. Al Gammal MICROTECHNIQUES Cells & tissues Organs Systems Human Body THE CELL Dr. Al Gammal  Structural & Functional unit of the human body Dr. Al Gammal  3 Cell membrane Cytoplasm Nucleus (except RBCs) Dr. Al Gammal 1 mm = 1000 micrometer (μm) 1 μm = 1000 nanometer (nm) Dr. Al Gammal A. R. Al Gammal Dr. Al Gammal Dr. Al Gammal Cell Membrane Dr. Al Gammal  Very thin Separates the cell Dr. Al Gammal LM Very thin to be seen (9-10 nm) Dr. Al Gammal  EM 3 layers (trilaminar) Outer & inner dark (electron dense) Middle light (electron lucent) Dr. Al Gammal Dr. Al Gammal Dr. Al Gammal Molecular Structures Dr. Al Gammal Dr. Al Gammal Lipids 1. Phospholipids Lipid bilayer Hydrophilic phosphate head (charged) (polar) (faces extracellular fluid) 2 long hydrophobic fatty acid tails (non-charged) (non polar) (face each other in the middle) 2. Cholesterol Dr. Al Gammal Dr. Al Gammal Proteins Intrinsic(integral) Incorporated in the lipid bilayer Transmembrane proteins Not easily extracted Extrinsic (peripheral) Loosely attached Easily extracted Dr. Al Gammal Carbohydrates Dr. Al Gammal Glycolipids Glycoproteins Glycocalyx Functions Dr. Al Gammal Exchange of materials Passive diffusion gases and ions Active transport aa, fa, glucose (need certain enz. & E.) Endocytosis Phagocytosis solid materials into the cell (phagosomes) Pinocytosis fluids into the cell (pinocytotic v.) Receptor mediated endocytosis hormones or lipoproteins into the cell (binding with membrane receptors) Exocytosis The cell expels out any material Sodium-potassium pump Polarized m. (high con. of Na+ outside & K+ inside) (active pump) Dr. Al Gammal QUESTIONS Dr. Al Gammal All of the following are found in or are associated with the external surface of the cell membrane Except: 1. Glycocalyx 2. Hydrophobic regions of phospholipids 3. Hydrophilic regions of phospholipids 4. Receptors for hormones Dr. Al Gammal Cell membrane is formed of: 1. Phospholipids & Cholesterol. 2. Proteins. 3. Oligosaccharides. 4. All of the above. 5. None of the above. Dr. Al Gammal At high magnification the cell membrane appears as: 1. Bilaminar structure 2. Trilaminar structure 3. Monolaminar structure 4. All of the above. 5. None of the above. Dr. Al Gammal Cell coat is: 1. The protein component of the cell membrane. 2. Carbohydrates attached to external surface of the membrane 3. Hydrophilic head of phospholipid 4. Inner layer of the cell membrane Dr. Al Gammal The following are the functions of the cell membrane EXCEPT: 1. It maintains and preserves the integrity of the cell 2. Oxidative phosphorylation of the cell 3. Permits the movement of substances in and out of the cell 4. Phagocytosis 5. Pinocytosis Dr. Al Gammal Cell membrane thickness is: 1. 5 – 10 μm. 2. 0.2 – 0.3 μm. 3. 9 – 10 nm. 4. 20 – 30 nm. Dr. Al Gammal Membranous Organelles Dr. Al Gammal Dr. Al Gammal Mitochondria Dr. Al Gammal Power house of the cell (ATP) LM H&E Could not be identified Special stains Iron H Dark blue Janus green B (supra-vital stain) Green Histochemically Fresh frozen sections Succinic dehydrogenase activity Dr. Al Gammal  Divide by simple binary fission Dr. Al Gammal EM Outer membrane Smooth Inner membrane Folded shelves (cristae) Enzymes Matrix Enzymes of citric acid cycle (Krebs cycle) DNA & RNA Ca++ or Mg++ (matrix granules) Dr. Al Gammal Dr. Al Gammal Dr. Al Gammal Functions Provide the cell with ATP needed for the different vital processes & activities Dr. Al Gammal QUESTIONS Dr. Al Gammal Compare between: Outer & Inner mitochondreal membranes Dr. Al Gammal Mitochondria are with a limited life span and maintain their number by: 1. Mitosis. 2. First meiotic division. 3. Second meiotic division. 4. Binary fission. 5. Meiosis. Dr. Al Gammal  The mitochondrial matrix contains: 1. Enzymes of citric acid cycle 2. DNA 3. RNA 4. Matrix granules rich in Ca++ or Mg++ 5. All of the above Dr. Al Gammal  The number of mitochondria present in a cell depends on its: 1. Size. 2. Shape. 3. Energy requirements. 4. Capability of division. 5. None of the above. Dr. Al Gammal  Concerning the mitochondria the following are true EXCEPT: 1. They contain enzymes of oxidative phosphorylation. 2. Bounded by two unit membranes. 3. They can divide by simple binary fission. 4. They contain DNA, RNA. 5. They contain some hydrolytic enzymes. Dr. Al Gammal The power houses of the cell are: 1. Polysomes. 2. Mitochondria. 3. Smooth endoplasmic reticulum. 4. Secretory vesicles. 5. Nucleus. Dr. Al Gammal The principle activity of mitochondria is : 1. Storage of fat. 2. Oxidative phosphorylation 3. Synthesis of steroid hormones. 4. Synthesis & breakdown of glycogen. 5. Package of secretory products. Dr. Al Gammal Mitochondria 1. Could be identified by H&E stain. 2. Could be stained vitally by Indian ink. 3. Could be stained supravitally by Janus green B. 4. Could be stained brown by silver stain. Dr. Al Gammal THANK YOU Dr. Al Gammal