Organic Chemicals of Life PDF

BIOLOGICAL SCIENCES ORGANIC CHEMICALS OF LIFE You are what you eat! 96 % human body mass is made up of just four elements: oxygen, carbon, hydrogen and nitrogen, mostly in the form of water-H2O. Most prominent compounds are macro nutrients which are needed in large amounts. Macron...

BIOLOGICAL SCIENCES ORGANIC CHEMICALS OF LIFE You are what you eat! 96 % human body mass is made up of just four elements: oxygen, carbon, hydrogen and nitrogen, mostly in the form of water-H2O. Most prominent compounds are macro nutrients which are needed in large amounts. Macronutrients provide calories, or energy and include foods like carbohydrates, proteins and fats. Micronutrients or trace elements are important but are required in small quantities eg Vitamins and mineral salts. Chemicals of life are grouped as Organic compounds and Inorganic compounds. ORGANIC CHEMICALS OF LIFE Organic compounds are involved in nearly all biochemical activities related to normal cellular metabolism and function. They include: 1. Proteins 2. Vitamins 3. Nucleic acids-DNA & RNA 4. Carbohydrates 5. Lipids INORGANIC CHEMICALS OF LIFE 1. Water 2. Mineral salts 3. Gases-oxygen 4. Acids & bases  PROTEINS These are organic food compounds composed of long chains of amino acids linked together by peptide bonds. Digestion of protein foods release amino acids which are compounds made of elements Nitrogen, carbon, hydrogen, oxygen and phosphorous or sulfur. Essential amino acids-from the foods eaten/diet include: histidine, isoleucine, leucine, lysine, methionine, Non-essential amino acids are synthesized in the body and include: alanine, arginine, asparagine. Most animal sources of proteins (meats, eggs milk etc) have complete set of essential amino acids (about10) while plant sources (beans, peas etc.) contain just a few.  FUNCTIONS OF PROTEINS 1.Structural proteins-Proteins are the building block of body structures. eg Collagen makes bone tissues strong. Collagen and elastin in skin makes it flexible and stretchable-tensile strength. Keratin is a strong, fibrous protein making structures like the skin, hair and nails. Myosin and actin proteins make up body muscles. Glycoproteins and lipoproteins make up cell membranes. Elastin in skin, uterus, lungs and arteries makes these vasodilation organs have high elasticity and stretchable preventing bursting. Skin &uterus can accommodate  Functions cont. 2.Enzymes are proteins that catalyse specific chemical reactions in the body. 3.Hormones- are the chemical messages produced by the endocrine glands controlling growth and development among others. Most hormones are protein in nature but some are steroids. 4.Transport- Albumin and haemoglobin are proteins that play a role in molecular transport. Heamoglobin transports gases –oxygen and Co2 while Albumin chemically binds to hormones, fatty acids, some vitamins, essential minerals, and drugs, and transports them throughout the circulatory system. 5.Protection-antibodies are proteins that help to fight invading pathogens-antigens in the body.  Cont. 6.Protein is required for the growth-hormones and maintenance of tissues/repair of worn out or injured cells. 7.Maintains proper pH-Proteins act as a buffer system, regulating the concentrations of acids and bases in the blood and other body fluids, just like other buffer systems in the body such as phosphates and bicarbonate. 8.Balances Fluids-Proteins regulate body processes to maintain fluid balance. Albumin and globulin are plasma proteins that help maintain body’s fluid balance by attracting and retaining water. 9.Provides Energy-Proteins can be an alternative substrate for respiration to produce energy during sickness, starvation etc.  VITAMINS Vitamin is an organic compound that comprise of groups of chemically related molecules called vitamers e.g eight vitamers of vitamin E: four tocopherols and four tocotrienols. They are essential micronutrient which an organism gets from diet but needed in small quantities for the proper functioning of its metabolism, normal cell function, growth and development. Essential nutrients cannot be synthesized in the organism, either at all or in sufficient quantities, and therefore must be obtained through the diet. Fruits and vegetables are the best food source for most vitamins.  TYPES OF VITAMINS Health organizations list the following thirteen types: Vitamin A (as all-trans-retinol, all-trans-retinyl-esters, as well as all-trans-beta-carotene and other provitamin A carotenoids), Vitamin B complex: Vitamin B (thiamine), vitamin 1 B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B7 (biotin), vitamin B9 (folic acid or folate), vitamin B12 (cobalamins), Vitamin C (ascorbic acid), Vitamin D (calciferols), Vitamin E (tocopherols and tocotrienols), and Vitamin K (phylloquinone and menaquinones).  GENERAL FUNCTIONS Vitamins have diverse biochemical functions. 1. Vitamin A acts as a regulator of cell and tissue growth and differentiation. 2. Vitamin D provides a hormone-like function, regulating mineral metabolism for bones and other organs. 3. The B complex vitamins function as enzyme cofactors (coenzymes) or their precursors. A coenzyme is an organic molecule that binds to the active sites of certain enzymes to assist in the catalysis of a reaction. 4. Vitamins C and E function as antioxidants that mop out free radicles in cells.  COENZYMES Enzymes are biological catalysts that can increase the rate of chemical reactions in living organisms. Enzymes can only function in specific pH, pressure, and temperature. They are highly specific and effective for each chemical reaction in the body. Some enzymes are associated with a non-protein molecules called coenzyme /cofactor that help in carrying out reactions that standard enzymes cannot. Cofactors may be small organic compounds such as vitamin C and Vitamin B- Flavin or inorganic metal ions like iron, zinc etc. The protein portion of the enzyme is called apoenzyme.  CATEGORIES OF VITAMINES 1.Fat-soluble vitamins are stored in the body's fatty tissue. The four fat-soluble vitamins are vitamins A, D, E, and K. These vitamins are absorbed more easily by the body in the presence of dietary fat. 2.Water soluble vitamins include ascorbic acid (vitamin C), thiamin, riboflavin, niacin, vitamin B6 (pyridoxine, pyridoxal, and pyridoxamine), folacin, vitamin B12, biotin, and pantothenic acid. They are not stored in the body and although, the body keeps a small reserve of these vitamins, they have to be taken on a regular basis to prevent shortage in the body. Any leftover water-soluble vitamins leave the body through the urine. Vitamin B12 is the only water-soluble vitamin that can be stored in the liver for many years.  VITAMIN A-RETINOL Vitamin A is a fat-soluble vitamin that helps form and maintain healthy skin, teeth, bones, and cell membranes. It also produces eye pigments, which are necessary for vision. Sources: Animal products like meat, fish, poultry, and dairy plant based fruits and coloured vegetables containing beta carotene like carrots, sweat potatoes, pumkins, etc Vitamin A deficiency can cause both temporary and permanent eye damage and may even lead to blindness. Vitamin A deficiency can also suppress immune function and increase mortality, especially among children and pregnant or breastfeeding women.  VITAMIN C-ASCOBIC ACID Vitamin C is an antioxidant that It protects the body’s cells from damage caused by free radicals. Free radicals can cause changes in cells and DNA that can lead to illnesses, including cancer. This vitamin also plays a key role in almost all of the body’s tissues helping them synthesise the protein collagen, for building and maintaining healthy bones, joints, skin and digestive tract tissues. Vitamin C is an important part of the immune system, which defends against infection by viruses, bacteria and other pathogens. Vitamin C vital to the immune system, helping prevent infections and fight disease. Source: citrus fruits-lemon apples pineapples, oranges passion etc. The human body does not store vitamin C, so people need to get this nutrient from their diet every day. It dissolves in water, and any excess leaves the body in urine. Vitamin C deficiency can result in a condition called scurvy that may cause: joint pain, bleeding gums, fatigue, problems with wound healing, depression, and tooth loss.  VITAMIN D-CALCIFEROL Vitamin D-sunshine vitamin is a fat-soluble vitamin that functions like a steroid hormone in the body telling cells to turn genes on or off. Vitamin D is produced from cholesterol in skin upon exposure to sunlight. Source: cod liver oil, fatty fish and egg yolks. Vitamin D plays a significant role absorption of calcium and phosphorus required for normal development and maintenance of healthy teeth and bones. Vitamin D deficiency in children can cause rickets, which leading to bowlegged or oxbow leg formation due to the softening of the bones. Similarly, in adults, vitamin D deficiency manifests as osteomalacia, or softening of the bones resulting in poor bone density, muscular weakness ,stunted growth and osteoporosis. Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to bone fragility and increase in fracture risk among the elderly people.  VITAMIN E-TOCOPHEROL Vitamin E (also known as tocopherol or alpha-tocopherol) are a class of fat-soluble compounds. Tocopherols exist in four forms-vitamers designated as α, β, δ and γ. All tocopherols are strong antioxidants-trapping reactive nitrogen species in cells to protect cells from damage reducing the risk of cancer. It is needed for nerve tissue health, proper brain function and production of red blood cells. It also helps prevent blood clots, boosts the immune system and protect body lipids from peroxidative degeneration/Free radicals-peroxides/ROS. Sources include: vegetable oils like soybean, sunflower, almond oil, peanuts, corn, sesame, cottonseed as well as asparagus, tomatoes, carrots and green leafy vegetables. Vitamin E deficiency can cause nerve and muscle damage , muscle weakness, vision problems and a weakened immune system.  VITAMIN K- PHYLLOQUINONE Vitamin K refers to a group of fat-soluble vitamins that play a role in blood clotting, bone metabolism, and regulating blood calcium levels. Human body requires vitamin K for post-synthesis modification of prothrombin, a protein and clotting factor required for blood coagulation/clotting to prevent excessive bleeding or for controlling binding of calcium in bones (bone metabolism). Source: Green leafy vegetables, like kale, spinach, turnip greens, collards,, mustard greens, parsley, lettuce, Brussels sprouts, broccoli, cauliflower and cabbage. Fish, liver, meat, eggs, and cereals. Deficiency is rare, but risk of uncontrolled bleeding -Haemophilia in severe cases may result, leading to hemorrhage and excessive bleeding from cuts and bruises.  VITAMIN B12 -COBALAMINE Vitamin B₁₂ is a water soluble and the largest and most structurally complicated of all the B complex vitamins. It is a cofactor in DNA synthesis/replication and regulation, involved in metabolism of fatty acid and amino acid, needed for nerve tissue health, proper brain function and the production of red blood cells and energy. Anaemia can occur if the red blood cell count drops. Source: fish, meat, poultry, pork, eggs, and dairy products-milk yogurt, cheese. Some types of soya milk and breakfast cereals are fortified with vitamin B12. It does not typically occur in plant foods. Vitamin B12 deficiency carries a serious risk of permanent nerve and brain damage. Some people with insufficient vitamin B12 have a higher risk of developing psychosis, mania, and dementia-memory loss.  VITAMIN B1-THIAMINE Vitamin B1, is a water-soluble vitamin that enables the body to use carbohydrates as energy. It is essential for glucose metabolism and plays a key role in nerve, muscle, and heart function. Source: germ of cereals, yeast, molasses, beef, pork, nuts, whole grains, cauliflower, liver, oranges, eggs, potatoes, asparagus, and kale. Thiamine deficiency leads to beriberi. Wet beriberi affects the cardiovascular system, resulting in a fast heart rate, shortness of breath, and leg swelling. Dry beriberi affects the nervous system, resulting in numbness of the hands and feet, confusion, trouble moving the legs, and pain.  NIACIN, OR VITAMIN B3 Vitamin B3 is a water-soluble B vitamin found naturally in some foods, added to foods and sold as a supplement. The two most common forms of niacin in food and supplements are nicotinic acid and nicotinamide. The body can also convert tryptophan —an amino acid—to nicotinamide. Niacin works in the body as a coenzyme, with more than 400 enzymes dependent on it for various reactions. Niacin helps to convert nutrients into energy, create cholesterol and fats, create and repair DNA, and exert antioxidant effects. Sources: Red meat: beef, beef liver, pork, Poultry, Fish, Brown rice ,Fortified cereals and breads, Nuts, seeds, Legumes and bananas. A niacin deficiency is rare because it is well-absorbed from most foods and is added to many foods and multivitamins. A severe niacin deficiency leads to pellagra, a condition that causes a dark, scaly rash to on skin exposed to sunlight; redness of the tongue; and constipation/diarrhea. Other signs of severe niacin deficiency include: Depression, Headache, Fatigue, Memory loss, Hallucinations  FOLATES-VITAMIN B9 VITAMIN B9 -Folate is water-soluble and naturally found in many foods and also added to foods as supplement in the form of folic acid. Folate helps to form DNA and RNA –transcription factors and is involved in protein metabolism-breaking down homocysteine, an amino acid that can exert harmful effects in the body if in high amounts. Folate is also needed to produce healthy red blood cells and is critical during periods of rapid growth- such as during pregnancy for fetal development. Expectant mothers are given folates/folic acid drugs. Sources : Leafy vegetables (turnip greens, spinach, lettuce, asparagus, Brussels sprouts, broccoli), Beans, Peanuts, Fresh fruits & fruit juices. Whole grains, Liver, Seafood, Eggs, Fortified foods and supplements. Signs of deficiency : megaloblastic anemia due to low red blood cells, fatigue; irregular heartbeat; hair loss; pale skin; mouth sores and neural tube defects.  ANTIOXIDANTS AND FREE RADICALS Oxidation reactions create unstable molecules/by products called ‘free radicals’ in tissues that steal electrons from other molecules. (ROS-reactive oxygen species & RNS) They damage the DNA, cell membranes, cellular proteins & lipids. Oxidation can be accelerated by stress, cigarette smoking, alcohol, sunlight, Pollutants and other factors. Effect of free radicals: 1. Deterioration of the eye lens contributing to vision loss. 2. Inflammation of the joints (arthritis). 3. Damage to nerve cells in the brain, which contributes to conditions (such as Parkinson’s or Alzheimer’s disease). 4. Acceleration of the ageing process. 5. Increased risk of coronary heart disease, since free radicals encourage LDL-bad cholesterol to stick to artery walls. 6. Certain cancers due to damaged DNA.  ANTIOXIDANTS Antioxidants scavenge and neutralize free radicals from the body cells so as to prevent or reduce the damage caused by oxidation. Nutrient antioxidants include Vitamins A- liver, sweet potatoes, carrots, milk, and egg yolks, Vitamin C – oranges, blackcurrants, kiwifruit, mangoes, broccoli, spinach, capsicum and strawberries Vitamin E – vegetable oils (such as wheat germ oil), avocados, nuts, seeds and whole grains. Mineral salts- copper, zinc and selenium. zinc is found in seafood, lean meat, milk and nuts Non-nutrient antioxidants include phytochemicals in plant foods like: Lycopene in tomatoes, grapes, watermelon and anthocyanins found in cranberries. Lutein, found in spinach and corn, Flavonoids such as catechins found in green tea and red wine, citrus fruits, onions, apples, Isoflavonoids – soybeans, lentils, peas and milk, Anthocyanins eggplant, grapes and berries, and Beta-carotene – pumpkin, mangoes, carrots, spinach and parsley.  CARBOHYDRATES Types of Carbohydrates: A saccharide refers to the unit structure of carbohydrates. Monosaccharides/ simple sugars- glucose, fructose, galactose, pentose, triose etc. are comprised of only one saccharide unit. Disaccharides/double sugars-sucrose, lactose, maltose etc comprise of two saccharide units. Oligosaccharides- Chain of 3-10 sugars eg raffinose and stachyose. Polysaccharides/complex sugars- starch, cellulose, glycogen, fibre. Sources of carbohydrates are fruits-fructose, milk-lactose,  Monosaccharides Monosaccharide are simple sugars (CH2O)n that can be utilized by cells for metabolism. Examples are; hexose-C6H12O6, triose-C3H6O3, pentose-C5H10O5 etc. depending on the number of carbons in their structure. A hexose is a six-carbon monosaccharide eg glucose, mannose, galactose, gulose, idose, talose, allose, altrose, fructose, piscose, sorbose, and tagatose all result from digestion of double and complex sugars. Glucose is the most common hexose that serves as a metabolic intermediate of cellular respiration. Pentose sugars are found in nucleotides of Nucleic acids: deoxyribose sugar in deoxyribonucleic acid (DNA) and Ribose sugar in ribonucleic acid (RNA).  Glycosidic bonds (glycosidic linkages) are the covalent bonds that join monosaccharides together during condensation/dehydration synthesis since it results in the release of water as a by product. The process, though, is reversible. Digestion/hydrolysis is the process where complex carbohydrates are broken down into simple sugars. Starch ,a complex sugar is digested to simple sugars. Glycogenosis is where stored glycogen is broken down into glucose for use in energy metabolism  GLUCOSE Glucose is the main sugar metabolized by the body to release energy ATP during respiration. The concentration of glucose in the bloodstream must be maintained within a narrow range of 70 to 115mg/100 ml of blood. The hormone insulin helps to convert excess glucose to glycogen for storage while hormone glucagon converts glycogen to glucose. Inadequate production of insulin by the pancreases leads to hyperglycemia-a condition where blood has high glucose level leading to Diabetes. Monosaccharides are the building blocks of disaccharides (such as sucrose and lactose) and polysaccharides (such as cellulose and starch). DISACCHARIDES Disaccharide- meaning "two sugars", or double sugars are commonly found in nature as sucrose- cane & beet sugar lactose-milk sugar and maltose-malt sugar. They are formed by a condensation reaction of two simple sugar molecules joined by a glyosidic bond. Examples are: Maltose=glucose +glucose Sucrose= glucose + fructose Lactose= glucose + galactose  LACTOSE-INTOLERANCE Lactose is a disaccharide formed through the condensation of glucose and galactose by a beta glycosidic bond. The alpha glycosidic bond, found in sucrose and maltose, differs from the beta glycosidic bond only in the angle of formation between the two sugars. Lactose intolerant people cannot digest beta glycosidic bonds in milk/lactose. Lactose intolerance or lactose malabsorption is the inability to fully digest sugar (lactose) in milk/dairy products due to deficiency of an enzyme- lactase in the body. Symptoms can include abdominal cramps, bloating and diarrhoea. Treatment focuses on avoidance of dairy products, use of lactose- free products or the use of lactase supplements.  OLIGOSACCHARIDES Oligosaccharides are carbohydrates that have between three and ten simple sugar units. Important oligosaccharides are raffinose and stachyose composed of repeating units of galactose, glucose and fructose found in beans and other legumes. They have unique glycosidic bonds that cannot be broken down into their simple sugars thus not absorbed by the small intestine. They are often metabolized by bacteria in the large intestine to form unwanted gaseous by products that course blooting/gas in the body/belly.  DIETARY FIBRE Dietary fibre are indigestible forms of polysaccharides present foods eaten cellulose, hemicellulose, pectin, gum and mucilage. Cellulose is by far the most abundant biochemical compound on the earth because it forms part of the structure of many plants like cell walls. Cellulose and most forms of hemicellulose are insoluble fibers while pectin, gum and mucilage are all soluble fibers and readily dissolve or swell when mixed with water. Consumption of soluble and insoluble fiber makes the elimination of feaces easier. Since dietary fiber is both indigestible and an attractant of water, stools become large and soft. Diet deficient in fibre leads to constipation, a condition where faeces are retained for long in colon requiring a lot of force during defecation. This results in formation of small pouches called diverticula and hemorrhoids. Heamorrhoids /piles, are swollen veins in anus and lower rectum, similar to varicose veins.  Fiber, is a type of carbohydrate/ roughage that is indigestible ie when eaten they pass through the digestive system relatively unchanged. It is found naturally in plant foods like wholegrains, beans, whole fruits and vegetables, nuts and seeds, popcorns, potatoes etc. Fiber has long been recommended by health professionals to help prevent and relieve constipation, good for healthy digestion, adds bulk to food making people feel full and reduce LDL-low density lipoproteins ("bad") cholesterol that which otherwise increases risk for heart disease and stroke.  SOURCE OF DIETARY FIBRE Fruits and Vegetables eg Apples, bananas, oranges, strawberries all have around 3 to 4 grams of fiber. Peels contain most fibre. Raspberries contain 8 grams per cup, mango has 5 grams, a persimmon has 6, and 1 cup of guava has about 9g. Dark-colored vegetables-especially the darker colored ones have higher fiber content. Carrots, beets, and broccoli, collard greens/kales and Swiss chard have 4 grams of fiber per cup. All types of potatoes, cereals -whole grains, beans, peas, lentils are fibre packed.  CONSTIPATION Constipation occurs when stool moves too slowly through the large intestines/ the colon allowing the body to absorb too much water from the stool/faeces making it hard, dry and difficult to pass. Complications of chronic constipation include: Swollen tissues around the anus, also called hemorrhoids. Torn tissues of the anus, also called anal fissures hence bleeding. Hard stools backed up into the colon, also called fecal impaction. Exposed tissues of the rectum that have slipped out of the anal opening, also called rectal prolapse.  FUNCTIONS OF CARBOHYDRATES Providing energy and regulating blood glucose-Glucose is the only sugar used by the body to provide energy for its tissues therefore, all types of carbohydrates must be converted into glucose and its level in blood controlled. Storage of energy. Excess glucose is stored in liver and muscles in form of glycogen- animal starch for later use. Any extra glucose is converted into triglycerides and stored as fats like adipose fat layer beneath the skin and organ surfaces. They Promote Digestive Health-Carbohydrates also provide dietary fiber that helps constipation. Structure formation-cellulose makes cell walls, glycoproteins form cell membranes. Peptidoglycan forms bacterial cell wall.  LIPIDS Lipids are organic compounds that include fats, oils, and waxes and certain hormones-steroids. The four main groups of lipids include: Fatty acids (saturated and unsaturated) Glycerides (glycerol-containing lipids) Non-glyceride lipids (sphingolipids, steroids, waxes) Complex lipids (lipoproteins= lipid+ proteins, glycolipids=glycogen+ lipid). The three primary types/classes of lipids are phospholipids, sterols, and triglycerides each playing a different role in the body.  Lipids are essential substances of all cells and serve as a major energy reserve. They may be stored as fatty acids or as triglycerides. Triglycerides are a type of fats present in blood that body cells use for energy production/burn calories. A triglyceride/lipid molecule is composed of glycerol +3 Fatty acids Triglycerides act as unused calories/sugars that may be converted to fats for storage or cause triglyceride build up in the bloodstream, increasing risk for heart attacks.  Cont. Cholesterol (waxy substance) is a type of lipid in blood needed to build healthy cells/cell membranes, produce sex hormones (testosterone and estrogen) and lipid soluble vitamins but high levels of cholesterol can increase the risk of heart disease. Cholesterol is a steroid in the human body processed in the liver and contributes to critical body functions like making of hormones, vitamin D, bile salts and cell membranes. Cholesterol is circulated/transported in bloodstream when attached to plasma proteins forming lipoproteins. Two types of lipoproteins that carry cholesterol in blood throughout the body are LDL and HDL  HDL is considered “good” cholesterol, as it absorbs and transport excess cholesterol in blood that the body does not need to the liver which gets rid of them before build up in arteries. LDL is “bad” cholesterol transports cholesterol to all body cells. Transport of high cholesterol levels results in formation of fatty deposits/plaque on the inner walls of blood vessels making them hard and narrow a condition called atherosclerosis/plague build up.  This condition makes it difficult for blood to flow normally hence increased pressure/hypertension. Some deposits form clots in blood vessels like carotid artery supplying brain resulting in heart attack and/or stroke. Atherosclerosis is a type of arteriosclerosis, a condition in which the arteries become stiff/hardened after the elastin fibres in artery walls loss elasticity.  PHOSPHOLIPIDS A phospholipid is a type of lipid molecule made up of two fatty acids, a phosphate group, and a glycerol molecule. Phospholipid=Lipid + phosphate group Phospholipids, along with glycolipids and cholesterol, are a major component of all biological membranes like cell membranes-lipid by layer. They comprise of a phosphate group head which is hydrophilic (water-loving) and a fatty acid tails which are hydrophobic (water-hating).  Most people never need to think much about phospholipids. However, there is a rare autoimmune disorder called antiphospholipid syndrome (APS), in which proteins on these lipids are attacked. The protective cell layers are damaged as a result. This disorder is seen more often in people with lupus, especially women. As APS attacks blood cells and vessels, it poses a risk of blood clots ("sticky blood") that can lead to heart attacks and strokes.  STEROLS Sterols are a subgroup of steroids- a type of hormone with a hydroxyl group at the 3-position of the A-ring. They are amphipathic lipids synthesized from acetyl-coenzyme A. Sterols are ringed lipids responsible for membrane integrity of eukaryotic cells/composition and regulation on the fluidity of cell membrane. They occur in the membranes of plants, animals, and microorganisms and are termed phytosterols, zoosterols, and mycosterols, respectively. Cholesterol is the main zoosterol, but sterols in plants commonly occur as mixtures with β-sitosterol, campesterol, and stigmasterol are major phytosterols.  Sterols play a vital role in cell signalling by helping regulate the process of development. Steroids are a man-made version of hormones designed to act like them to reduce inflammation. They’re also known as corticosteroids and are different from anabolic steroids used by bodybuilders and athletes. Anabolic steroids like Anabolic-androgenic steroids (AASs) are related to testosterone hormone. They function by increasing the synthesis of proteins in cells to build up muscles, stimulate bone growth and appetite hence body builders favorite drug.  TRIGLYCERIDES Triglycerides are the common fats and oils that you are familiar with in foods. This type of lipid can be saturated or unsaturated, which is part of what makes them liquid or solid at room temperature. Saturated fats and unsaturated fats are found in a variety of foods. It is recommended that between 20 and 35% of total daily calories should consist of unsaturated fat. Oils are unsaturated fats that exist in liquid form at room temperature. E.g. canola oil, corn oil, and olive oil. Unsaturated fats chemical structure contains one or more double bonds.  SATURATED FATS Saturated fats have no double bonds in their chemical structure. They are saturated with hydrogen atoms. Because of their chemical structure, they have a solid consistency at room temperature. Saturated fats can be found in a variety of foods, including: Animal meat including beef, poultry, pork, Certain plant oils such as palm kernel or coconut oil Dairy products including cheese, butter, and milk Processed meats including bologna, sausages, hot dogs, and bacon. Pre-packaged snacks including crackers, chips, cookies, and pastries.  Why Limit Saturated Fats in Your Diet Some studies have shown that consuming a high amount of saturated fats may increase bad cholesterol level- low density lipoproteins (LDL), therefore risk of Heart disease. However, there have been multiple studies that refute the detrimental effects of saturated fat.5 Omega fatty acids are essential nutrients that come from certain foods like fish (Tuna and salmon), some nuts, seeds, and leafy vegetables. These fats reduce inflammation, blood pressure, and triglyceride levels. They reduce the risk of sudden death by a heart attack and prevent formation of blood clots-thrombosis that may lead stroke. Tran’s fats are fats that have been artificially hydrogenated so that they have a texture desired for processed foods. Eating foods that contain trans fats can lead to high levels of low-density lipoprotein (LDL), also called "bad cholesterol."  FUNCTIONS OF LIPIDS-Role of Lipids in the Body 1. Nervous System- Lipids are integral to the nervous system and found in its myelin sheaths. These are the fatty tissue sleeves that protect the nerve cells and increase the impulse conduction ability. 2. Vitamin Absorption-Lipids help the body to absorb fat-soluble vitamins (A, D, E, and K). 3. Hormone Production-Lipids are used in the production of certain hormones like estrogen, testosterone, and cortisol. 4. Energy production-lipids are used as substrates for energy (ATP) production during respiration in absence of sugars/glucose. 5. Insulation-Adipose fat tissues beneath the skin prevent heat loss. 6. Structure formation-phospholipids are components of cell membranes.  NUCLEIC ACIDS Nucleic acids are large organic compounds that store and process information at the molecular level inside virtually all body cells. Two types of nucleic acids are present: Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA) Adenosine triphosphate (ATP) DNA and RNA are the molecules of life necessary for reproduction-hormones, growth and development, protein synthesis-genes, metabolism-enzymes. DNA is in the nucleus and mitochondria of eukaryotes and makes up the chromosomes of cells. It is the genetic code for hereditary characteristics.  Cont. RNA are transcribed from DNA and play important roles in protein synthesis and gene regulation. Nucleic acids are very large molecules composed of smaller units known as nucleotides. A nucleotide consists of a pentose sugar, a phosphate group, and four nitrogenous bases- AGCT or U in RNA. DNA is made of a pentose sugar-deoxyribose and bases Adenine, Guanine, Cytosine, and  HIGH-ENERGY COMPOUNDS Adenosine triphosphate (ATP) is a specialized nucleotide located in the cytoplasm of cells and serves as a source of cellular energy. ATP is energy currency of cells powering biosynthetic reactions, motility, cell division, metabolism etc. Guanosine triphosphate (GTP) is another high energy compound that can be hydrolyse to release energy used during protein synthesis, muscle contraction and other metabolic activities. GTP may be converted to ATP via the  Cells require large amount of chemical energy (ATP) for all important activities like metabolism, contraction and relaxation to course movements and locomotion etc. Active transport of molecules and ions across cell membranes and Synthesis of macromolecules and biomolecules eg proteins. This energy is produced in mitochondria of most cells by a process called Respiration-either aerobic that requires oxygen or anaerobic. Energy in these bonds is liberated by hydrolysis of ATP to form ADP or GTP to form GDP.  FUNCTIONS OF NUCLEIC ACIDS- DNA & RNA DNA and RNA perform different functions in humans. 1.DNA is responsible for storing and transferring genetic information to new cells during cell division. 2.DNA fingerprinting- is a chemical test that shows the genetic makeup of a person or other living organisms. It's used as evidence in courts-crime investigation, to identify bodies burnt without recognition, paternity test, disease diagnosis and to look for cures for disease-mRNA Covid 19 vaccines and cancer therapy.  Cont. A genetically modified organism (GMO) is any organism whose genetic material has been altered using genetic engineering techniques- Recombinant DNA technology. Bacteria, viruses, plants and animals have been genetically modified for academic, medical, agricultural, and industrial purposes GMOs are a source of medicines and genetically modified foods and are also widely used in scientific research, along with the production of other goods. Development of Transgenic Plants-Genetically transformed plants which contain foreign genes making them drought and disease resistant.  Cont. Genetic engineering helps in the production of antibiotics, hormones like insulin, vaccines and interferon. Penicillium and Streptomyces fungi are used for mass production of antibiotics penicillin and streptomycin. Genetically efficient strains of these fungi have been developed to greatly increase the yield of these antibiotics. Human gene for insulin production has been incorporated into bacterial DNA and such genetically engineered bacteria are used for large scale production of insulin. Gene Therapy- Genetic engineering may one day enable the medical scientists to replace the defective genes responsible for hereditary diseases (e.g., haemophilia, sickle cell anaemia) with normal genes. This new system of therapy is called gene therapy. In industries, recombinant DNA technique helps in the production of efficient strains of microorganisms for improvement of existing fermentation processes, production of proteins from wastes and cleaning up the pollutants like oil spills in beaches. END