MODULE 2_ Cell and transport mechanism.pdf

MODULE 2: Cell and Transport Mechanism Prepared by: Ms. Cherry Pie G. Fernandez, LPT. OBJECTIVES: Locate the stages of mitosis in onion root tips Distinguish the various stages of mitosis Identify and describe the cell and its organelles Understand the nature and processes of the different ty...

MODULE 2: Cell and Transport Mechanism Prepared by: Ms. Cherry Pie G. Fernandez, LPT. OBJECTIVES: Locate the stages of mitosis in onion root tips Distinguish the various stages of mitosis Identify and describe the cell and its organelles Understand the nature and processes of the different types of transport mechanisms. Answer the questions for research. Materials Needed Beakers Stirring rod 1 funnel Raisins 1 tsp sugar 1 tsp coffee granules Copper sulfate solution Charcoal Starch solution Procedure TRANSPORT MECHANISM SET UP A 1. Place 5 pieces of dried raisins in a beaker full of water 2. Let it stand at room temperature 3. Check for any change in the APPEARANCE of the raisins until an observable change is noted. 4. Record and draw your results. Procedure SET UP B 1. Place 2 beakers half full of water 2. Place ½ tsp sugar in each beaker 3. On the first beaker, stir the contents until all the sugar is dissolved. NOTE the TIME required to dissolve the sugar. 4. Allow the second beaker to stand undisturbed until all sugar has been dissolved. NOTE the time required to dissolve the sugar 5. Record and draw your set-up. Procedure SET UP C 1. Add 100 ml of cold water in one beaker and 100 ml of hot water into another beaker. 2. Plac a teaspoon of coffee granules in both beakers. 3. Let it stand and be careful not to disturb the dishes, 4. Observe what happens and note the time required for the granules to evenly distribute in the water, 5. Record and draw your results. Procedure SET UP D 1. MIx a pinch of charcoal, 2 ml of copper sulfate solution and boiled starch w/ 5ml of distiilled water. 2. Position the funnel over an empty flask and pour the mixture into it. 3. Observe the speed of the process 4. When all the solution has been transferred in the receiving container, get the filtrate and test for the iodine solution, A change in color (purple indicates the presence of starch in the filtrate) 5. Record you results.  CELL DIVISION Process by which cell divides into two or more daughter cells. For growth (cell number not in size) For repairing (old or damaged cells)  Somatic cells (Mitosis) Purpose: Growth, tissue, repair and maintenance Number of Chromosomes: diploid (2n), two sets of chromosomes Process: Divides into two identical daughter cells Result: Maintains the same chromosome number as the parent cell Gamete Cell (Meiosis) Purpose: Sexual reproduction, formation of sperm and egg cells. Number of Chromosomes: Haploid (n), one set of chromosomes Process: divides into four daughter cells, each with half the number of chromosome as the parent cell Result: Introduces genetic diversity among offspring Cell division Cell cycle- is the process in which cells grow and divide Cell division always results into 2 new cells called daughter cells which came from a parent cell. The resulting cells (daughter cells) have the same type and number of chromosomes. Phases of Cell Division Interphase Mitotic phase Prophase Metaphase Anaphase Telophase Interphase The phase wherein the cell is preparing to divide. Interphase also has 3 phases: G1, S, G2. One state of Interphase is the G0 which the cell is not in an active state of division. Phases of Interphase G1- replication of organelles and other cellular components, but not the DNA yet. S phase- the phase between G1 and G2, DNA is replicated during this phase. G2- continuation of cell growth, protein synthesis and centrosome replication. Mitotic Phases: Prophase Disintegration of the Nucleolus Chromatin condenses into chromosomes Chromosomes are visible under the microscope Each chromosome strand are made up of a pair chromatids Between each chromosome, a centromere constricts the pair of chromatids at the center. Formation of mitotic spindles which are made up of microtubules. Metaphase Alignment of chromosomes at the center/ metaphase plate Anaphase Centromeres are split, and move to opposite poles Telophase The nuclear envelope forms Chromosomes uncoil and form into chromatins Mitotic/ spindle fibers disappear Cytokinesis The cytoplasm divides Starts either during late anaphase or early telophase For animal cells, cleavage furrows form For plant cells, a cell plate forms, which is quite visible on a microscope. Phases of Cell Division Cytokinesis Cancer Uncontrolled growth and spread of abnormal cells that invade and destroy normal tissues and organs in the body. It can arise almost anywhere in the body and affect any tissue or organ. Normal cells undergo genetic mutations causing uncontrolled and form a tumor, Types of tumors: Benign Tumors: non cancerous tumors, do not invade tissues or spread rapidly Malignant tumors: cancerous tumors, invade nearby tissues and spread though the bloodstream or lymphatic system, metastasis Types of Cancer Majority of human cancers are malignant tumors that came from epithelial cells. These are called carcinomas. Melanomas: cancer of the skin Sarcoma: cancer of the skin Osteogenic sarcoma: cancer from arising bones Leukemia: cancer from the bone marrow Lymphoma: cancer of the lymphatic tissues Cell Transport Mechanism Cell Membrane Is a biological membrane that surrounds the cytoplasm of a cell. It is a semi- permeable membrane Functions: Boundary: forms outer boundary of the cell, separating internal cellular environment from the external environment. Selective permeability: controls movement of substances (ions, nutrients and waste products) Cell recognition: recognition and immune response Plasma Membrane Refers specifically to the membrane that surrounds the cell, separating its internal contents from extracellular environment. The structure of the plasma membrane consist of phospholipid bilayer. Plasma Membrane The phospholipid bilayer is made up of hydrophilic “heads” and hydrophobic “tails” Gradients across the Plasma Membrane Concentration Gradient - Difference in the concentration of a chemical from one place to another (inside to outside of plasma membrane) Gradients across the Plasma Membrane Electrical Gradient - Difference in the electrical charges between two regions Membrane potential - Is the term used for difference in charge Gradients across the Plasma Membrane Electrochemical Gradient - Combined influence of the concentration gradient and electrical gradient on the movement of an ion. Transport Mechanisms Passive transport - A substance moves down or with its concentration or electrical gradient without the use of energy or ATP Active Transport - In opposite of passive transport, this mode of transport mechanism involves the use of energy or ATP. Passive Transport Diffusion - Random mixing of particles in solution due to the particles kinetic energy - From an area of higher solute concentration to an area of lower solute concentration. Passive Transport Diffusion Channel- mediated facilitated diffusion - Through membrane channels (mostly ion channels) that allow passage of small, inorganic ions. - Leak and gated channels Passive Transport Diffusion Carrier- mediated facilitated diffusion - Carrier or transporter that undergoes changes in shape - The rate is determined by the steepness of the concentration gradient - Transport maximum and saturation Factors that Influence the rate of diffusion STEEPNESS OF THE DIRECTLY PROPORTIONAL CONCENTRATION GRADIENT TEMPERATURE DIRECTLY PROPORTIONAL MASS OF THE DIFFUSING SUBSTANCE INDIRECTLY PROPOTIONAL SURFACE AREA DIRECTLY PROPORTIONAL DIFFUSION SUBSTANCE INDIRECTLY PROPORTIONAL Passive Transport Osmosis - The diffusion of water from an area of higher concentration to an area of lower water concentration - Or lower solute concentration to an area of higher solute concentration - Through aquaporins Tonicity Active Transport Energy is required for carrier proteins to move solutes against a concentration gradient Transport maximum and saturation Two sources of cellular energy: - Hydrolysis of ATP (primary active transport) - Energy stored in an iconic concentration gradient (secondary active transport) Active Transport Primary Active Transport - Energy derived from hydrolysis of ATP changes the shape of a carrier protein which pumps a substance across the membrane against its concentration gradient (pump)  Active Transport Secondary Active Transport - The energy stored in an iconic concentration gradient is used: indirectly uses energy obtained from the hydrolysis of ATP - Symporters- move two substances in the same direction - Antiporters- in opposite directions Active Transport Vesicles Endocytosis - Materials move into the cell in a vesicle formed from the plasma membrane Active Transport 3 types of endocytosis Receptor-mediated endocytosis- highly selective; cells take up selector ligands, imports materials that are needed by cells Phagocytosis- cells engulf large solid particles such as bacteria or viruses; phagocytes Bulk-phase or pinocytosis- tiny droplets of extracellular fluid are taken up Active transport Exocytosis - Materials move out of the cell by fusion with the plasma membrane of vesicles formed inside the cell Cellular Pathophysiology Tonicity in relation to RBCs RBCs destroyed in hypertonic or hypotonic solutions (IV solutions are isotonic) Hypertonic solutions- cerebral edema Hypotonic solutions- dehydration Cellular Pathophysiology Sodium-potassium pump Digitalis- patients with heart failure; slows the action of sodium potassium pumps Excess calcium= increase the force of the contractions Cellular Pathophysiology Virus and receptor- mediated endocytosis HIV= CD4 (helper T- cell) Cellular Pathophysiology Cystic Fibrosis - This is a genetic disorder that affects the active transport of chloride ions into cells - Less water moving into the tubes causing the tubes to become clogged with mucus Cellular Pathophysiology Emphysema Lung disease; damage to walls of air sacs (alveoli) of lungs Alveoli= large surface area for diffusion of O2 from air into blood Emphysema- reduces surface area= slow diffusion rate= DOB References Tortora, G. J., & Derrickson, B. (2017). Tortora's Principles of Anatomy & Physiology 15th ed. John Wiley & Sons, Inc. Van Putte, Regan, and Russo. (2016). Seeley’s Essentials of Anatomy and Physiology. 9th Ed. USA: McGraw-Hill.