Effects of Lack of Vitamins and Minerals Human body cannot synthesize most vitamins and minerals. You are supposed to provide these nutrients to your body through healthy diet. There has been an astounding rise in the sale of vitamin and mineral supplements over the last few decades. It is good that more and more people are becoming health conscious but it also suggests that more and more people are suffering from vitamin and mineral deficiencies. Either inadequate intake of vitamins and minerals through diet or inadequate absorption of vitamins and minerals in the digestive tract are the main causes of lack of vitamins and minerals in the body. Vitamins and Minerals Vitamin A and beta carotene, B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folic acid), B12 (cobalamin), C (ascorbic acid), D (ergo/cholecalciferol), E (tocopherol) and vitamin K (quinones) are the main vitamins required by the body. Effects of Lack of Vitamins Vitamin A Recommended Daily Intake Vitamin B1 Calcium
2.4 Membranes | BioNinja 2.4.1 Draw and label a diagram to show the structure of membranes 2.4.2 Explain how the hydrophilic and hydrophobic properties of phospholipids help to maintain the structure of cell membranes Structure of Phospholipids Consist of a polar head (hydrophilic) made from glycerol and phosphateConsist of two non-polar fatty acid tails (hydrophobic) Arrangement in Membrane Phospholipids spontaneously arrange in a bilayerHydrophobic tail regions face inwards and are shielded from the surrounding polar fluid while the two hydrophilic head regions associate with the cytosolic and extracellular environments respectively Structural Properties of Phospholipid Bilayer 2.4.3 List the functions of membrane proteins Transport: Protein channels (facilitated) and protein pumps (active) Receptors: Peptide-based hormones (insulin, glucagon, etc.) Anchorage: Cytoskeleton attachments and extracellular matrix Cell recognition: MHC proteins and antigens Intercellular joinings: Tight junctions and plasmodesmata Osmosis:
Real-life applications - Osmosis - Cell Behavior and Salt Water, Osmosis in Plants, Osmosis and Medicine Cell Behavior and Salt Water Cells in the human body and in the bodies of all living things behave like microscopic bags of solution housed in a semipermeable membrane. The health and indeed the very survival of a person, animal, or plant depends on the ability of (Bettmann/Corbis . Reproduced by permission.) the cells to maintain their concentration of solutes. Two illustrations involving salt water demonstrate how osmosis can produce disastrous effects in living things. Worse still is the process that occurs when a person drinks salt water. How, then, do fish and other forms of marine life survive in a salt-water environment? Osmosis in Plants Plants depend on osmosis to move water from their roots to their leaves. Crucial to the operation of osmosis in plants are "guard cells," specialized cells dispersed along the surface of the leaves. In some situations, external stimuli such as sunlight may cause the guard cells to draw in potassium from other cells. Osmosis and Medicine
Investigating osmosis in chickens’ eggs In this procedure, you can observe osmosis in an animal system by using chickens’ eggs from which the shells have been removed by dissolving in acid. The eggs are weighed and placed in solutions of different strength for 24-48 hours before being weighed again. You can run this as a demonstration, or a class practical where pairs of pupil have an egg and each pair place their eggs in different solutions (amalgamating results to provide whole-class data). Paper towel Beaker, 200 cm3 150 cm3 of each salt solution to be used. Balance De-shelled eggs (Note 1) Sodium chloride solutions in a range of concentrations, for example, 0%, 10%, 20%. (150 cm3 of each concentration for each working group) Hydrochloric acid (HCl) is described as IRRITANT at concentrations above 2.0 M, causes burns and is irritating to the respiratory system. Sodium chloride is described as low hazard. Wear eye protection as some of the sodium chloride solutions are strong. Rinse hands if splashed by solutions. Preparation