Module 2 General Biology - Cells PDF

LESSON 7 ORGANIC AND INORGANIC COMPOUNDS Organic Compounds The organic materials are used as a source of energy within the cells. They are also important in building new tissues and synthesizing physiologically important chemicals such as hormones...

LESSON 7 ORGANIC AND INORGANIC COMPOUNDS Organic Compounds The organic materials are used as a source of energy within the cells. They are also important in building new tissues and synthesizing physiologically important chemicals such as hormones and enzymes. A. Carbohydrates These are substances containing carbon, hydrogen, and oxygen is present in the same ratio as water. Thus this general formula is Cn(H2O)n. Simple carbohydrates are known as sugars/ The primary sources of energy for cellular activities within the cell. They are broken down by combination with oxygen, and the released energy can be used to perform cellular work. These can also be converted to other types of molecules from part of the cell for other physiological functions. Ex. Glycogen and fat. They are usually classified according to the number of sugar units in their molecules. These are the following: o Monosaccharides ▪ The simplest sugar is containing only one sugar molecule. ▪ The number of carbon atoms usually varies from 3-7. 🗆 Examples: 1. Triose (3C atoms) glycerose C3H6O3 2. Tetrose (4C atoms) threose C4H8O4 3. Pentose (5C atoms) ribose C5H10O 4. Hexose (6C atoms) glucose, fructose, galactose, mannose C6H12O6 5. Heptoses (7C atoms) mannoheptose C7H14O7 ▪ The most important of these are the hexoses (glucose, fructose, and galactose). ▪ Among these three, glucose is said to be the most physiologically significant as it is the primary sugar transported by the blood cells. Thus it is always referred to as blood sugar. The other two monosaccharides, fructose, and galactose are converted to glucose before they are used by the cel o Disaccharides ▪ Consists of two molecules of monosaccharides ▪ The most common of these are: 🗆 Sucrose (glucose and fructose) - It is known as the common table sugar, an extract of beet or sugar cane. - It formed an increasingly larger portion of a man’s diet. - Large consumption may lead to diabetes and heart disease 🗆 Lactose (glucose and galactose) - It is the kind of sugar found in milk. - Normally, it is broken in the digestive tract into monosaccharides, which are absorbed in the blood - Some individuals cannot break down lactose in their digestive tract, so that it leaves the individual exceeding undernourished. This can also cause severe diarrhea. 🗆 Maltose (glucose and glucose)  - It is found in fruit juices and sprouting grains. o Polysaccharides ▪ Consists of a large number of monosaccharide units ▪ Examples are: Glycogen - the form in which glucose is stored in the animal body; Starch – the state in which glucose is stored in the plant body. Cellulose - a tough fibrous material that holds together the plant structure. B. Proteins Substances were containing the elements carbon, hydrogen, oxygen, and nitrogen. Some also contain sulfur and phosphorus. They are the building blocks from which the cells are formed, and they regulate the chemical activity inside the cell. They also act as catalysts (enzymes) for several cellular reactions and are responsible for muscle contraction. They are also essential in repairing damaged or worn-out cells and tissues. They act as antibodies which fight diseases and infections. They are composed of a chain of smaller subunits called amino acids. They are compounds that contain the amino group (-NH2). There are two groups of amino acids, namely: o Non-essential Amino Acids- these are synthesized in the body. Examples – alanine, serine, glycine, aspartic acid, glutamic acid, proline, hydroxyproline, citrulline, cysteine, tyrosine, norleucine, and hydroxyglutamic acid. o Essential Amino Acids- these must be supplied in the diet. Examples – histidine, isoleucine, leucine, lysine, methionine, arginine, phenylalanine, threonine, valine, tryptophan Most animal proteins are complete proteins that consist of all the essential amino acids, while plant proteins are generally incomplete. The amino acids of proteins are held together by peptide bonds (-CO-NH-). About 3.5 % of the total protein present in the body may be destroyed and resynthesized. Protein from the diet is, therefore, very essential to replace the continuous breakdown of body proteins. There are different types of protein based on their function in the organisms. Type of Protein Function Examples 1. Structural Provides Insects and spiders use silk fibers Protein mechanical shape (fibroin, protein in silk) to make their and support cocoons and webs Collagen and elastin provide a fibrous framework in animal connective tissues such as tendon and ligaments Keratin is the protein of hair, horn, feathers, and other skin appendages Dentine is a protein that strengthens teeth 2. Storage Storage of amino Ovalbumin is the protein of egg white Protein acid which is used as an amino acid source for developing embryo Casein, the protein of milk, is the major source of amino acids for baby mammals. Plants store proteins in seeds  3. Transport Carry or transport Hemoglobin, the iron containing protein of Protein substances vertebrae blood, transport oxygen from the lungs to other parts of the body Serum albumin carries fatty acid in the blood Other proteins transport molecules across cell membranes 4. Receptor Response of cell Receptors built into a membrane of a Protein to chemical nerve cell detect chemical signals stimuli released by other nerve cell 5. Hormonal Coordination of Insulin and glucagon, hormones secreted Proteins an organism’s by the pancreas help regulate the activities concentration of sugar in the blood of vertebrates Prolactin, stimulates milk production and secretion GH (growth hormone), stimulates growth and metabolic functions 6. Contractile Movement Actin and myosin are responsible for the Protein movement of muscles 7. Defensive Protection against Antibodies combat bacteria and viruses; Protein diseases ex. Immunoglobulins destroy bacteria 8. Enzymatic Selective Digestive enzymes hydrolyze the polymers in Protein acceleration of food, ex. ptyalin that acts on carbohydrates chemical and trypsin that acts on protein. reactions C. Nucleic Acids (the non-protein portion of nucleoproteins) These are macromolecules found in animal and plant cells They participate in the storage, transmission, and translation of genetic information. Properties include the following: 1. Insoluble in alcohol; soluble in cold water; readily dissolves in hot water, and dilute alkalis forming alkali salts. 2. They are precipitated by HCI and by excess Acetic Acid. 3. They have a high molecular weight ranging from 1,286 to 3,000,000 4. They are two types: a. Ribonucleic Acid b. Deoxyribonucleic acid 5. The element composition of nucleic acids are the following: a. Carbon b. Hydrogen c. Oxygen d. Nitrogen (15-16%) e. Phosphorus (9-10%) 6. Upon hydrolysis, which enzymes or after heating with dilute acids and alkalis, nucleic acids yield a group of compounds known as nucleotides. On further hydrolysis, nucleotides split into phosphoric acid and nucleosides, which in turn are composed of sugar (ribose or deoxyribose) and a nitrogenous base (purine or pyrimidine). a. Purines: adenine (A) and guanine (G) b. Pyrimidines: cytosine (C), thymine (T), and uracil (U) DNA Strands Nucleic acids are molecules produced by living cells and are essential to all living organisms. These acids govern the body’s development and specific characteristics by providing genetic information and triggering proteins' production. This computer-generated model shows two strands of  deoxyribonucleic acid (DNA) and the double- helical structure typical of this class of nucleic acids. Table Showing the differences between Ribonucleic Acid and Deoxyribonucleic Acid Points of Difference Ribonucleic Acid Deoxyribonucleic Acid 1. Sugar Ribose Deoxyribose 2. Location in the Cell Predominates in the Found in the Nucleus Cytoplasm 3. Main Function Translation of information Storage of Genetic into protein structures Information 4. Pyrimidine base Cytosine and Uracil Cytosine and Thymine Deoxyribonucleic Acid (DNA) This is the chromosomal material containing the generic information of living cells. The base sequences of DNA constitute a template or mold. (A-T-G-C). This template or mold determines the complementary partner. For the given example above, the complementary partner is (T-A-C-G). Therefore, DNA is a double helix (spiral structure; twisted ladder). The number of adenine bases equals the number of thymine; the number of guanines equals the number of cytosine bases. The sides of the ladder are made up of alternating sugar and phosphate molecules. The ladder's rungs (steps) are made up of nitrogen bases held together by hydrogen bonds. In addition to hydrogen bonds, evidence show that hydrophobic forces between purine and pyrimidine nuclei contribute to the maintenance of the rigid, two- stranded structure. Denaturation of DNA can be caused by several factors such as: a. Acids b. Alkali c. Heat d. Low ionic strength e. Urea f. Formamide Ribonucleic Acid (RNA) Consists of long strings of single-stranded ribonucleotide They are much shorter than DNA but more abundant. RNA is hydrolyzed by weak alkali with the formation of an intermediate phosphate triester. There are three types of RNA 1. Messenger RNA (mRNA) Functions as a template or information RNA. This is used by ribosomes for translation of genetic i nformation into the amino acid sequence of the protein. 2. Transfer RNA (tRNA)/ soluble RNA Makeup around 10 to 20% of cellular RNA. Consists of a single strand of ribonucleotides that are highly folded in conformation. It is a small molecule containing 70-90 ribonucleotides with a molecular weight of 23,000 to 30,000. It serves to bind and carry the activated amino acids to the ribosomes and serves as an adapter for translating genetic codewords of mRNA  into an amino acid sequence (anticodon). Anticodon is complementary to the codon, the trivalent nucleotide sequence of mRNA, which codes for one specific amino acid. 3. Ribosomal RNA (rRNA) The significant component of ribosomes. Makeup around 65% of their weight. This is strongly associated with protein and is stable. It plays an essential role in the structure and biosynthetic function of ribosomes. 4. Lipids These are groups of carbon-containing compounds characterized by the fact that they do not dissolve readily in water. The essential elements in lipids are carbon, hydrogen, and oxygen like carbohydrates; however, lipids contain a much smaller proportion of oxygen atoms than carbohydrates. Lipids are heterogeneous compounds. The three most important groups are: A. Fats The most common lipids in the body These are trimesters of fatty acids and glycerol. They can be classified as either: a. Saturated Those that do not contain double bonds between carbons. Characteristics of animal fats. Excess of these may lead to cholesterol deposits leading to cardiovascular disease. b. Unsaturated Those that contain double bonds between some of the carbon atoms. Characteristics of vegetable fats. These are less hazardous as far as health is concerned. B. Phospholipids Structurally similar to fats, except a group containing phosphorus or nitrogen is attached to one of the carbons of glycerol. They are an essential part of the membrane surrounding the cell. C. Steroids Composed of interconnected carbon rings. These compounds are absorbed intact or in slightly modified form. Examples are Testosterone¬ - male reproductive hormone. Estrogen – female reproductive organ. 5. Vitamins These are the organic substances present in small amounts in natural foodstuffs which are essential for growth and normal metabolism Vitamins needed by the body come mostly from the diet. Generally, a minimal amount is enough to supply the needs of the body. Deficiency may lead to disease. The same is true with excess, particularly fat-soluble vitamins. Vitamins are classified into: A. Fat-soluble Vitamins  Readily soluble in fats and oils. A. Vitamin A Formed in the liver from carotenoid pigments, which are found in leafy green vegetables, yellow fruits, and vegetables. It is concerned with the growth of bone, teeth, and epithelial tissues and the synthesis of rhodopsin, the light-sensitive pigment of the retina's rod cells. B. Vitamin D Has anti-ricketic properties Includes irradiated ergosterol (D2) and calciferol (D3). The sources of this vitamin are cod liver oil. It is also formed in the skin in response to ultraviolet light, which we get from the sun. This vitamin is required for average growth, absorption of calcium, phosphorus from the intestine, and calcium and phosphorus utilization to develop bones and teeth. It is linked in the phosphate enzyme system, perhaps with parathyroid glands. A deficiency in children results in rickets characterized by soft and fragile bones. Children with rickets are bow- legged. In infants, the fontanels do not close. C. Vitamin D Vitamin D is found in leafy green vegetables, vegetable oils, unmilled cereals, corn, nuts, and eggs. It is important for the normal growth and development, utilization of sex hormones, cholesterol, and Vitamin D. Its deficiency is found to be responsible for cystic fibrosis and premature aging. D. Vitamin K Found in liver, spinach, cauliflower, and cabbage. It is synthesized to a small degree by bacteria in the large intestine. It is necessary for prothrombin synthesis in the liver. A deficiency is sometimes seen in newborn infants because the large intestine's bacterial flora has not yet developed. Those infants have difficulty forming blood clots so that there is a tendency for hemorrhage. B. Water-Soluble Vitamins This classification was based on the vitamins’ solubility in water and their nitrogen content (B complex). A. Thiamine (B2) This is necessary for the conversion of glucose and pyruvic acid during the breakdown of carbohydrates. Deficiency leads to the disorder of the nervous system and heart failure. This condition is called beriberi, characterized by anorexia, loss of weight, debility, peripheral neuritis, and edema. The heart is usually enlarged, and there is a high level of pyruvic acid and lactic acid in the blood. B. Riboflavin(B2) Important in the metabolism of all types of foodstuffs. Deficiency in man is characterized by glossitis, cheilosis, and seborrheic dermatitis.  C. Niacin/ Nicotinic Acid (B3) Present in meat, poultry, fish, yeast, peanut butter, potatoes, and legumes. Niacin is a functional component of co-enzymes, essential in developing the enzymes involved in releasing energy from foodstuffs. Pellagra is the disease caused by lacked niacin. It is characterized by fatigue, headache, anorexia, backache, loss of weight, sore tongue, mouth, throat, anemia, vomiting, diarrhea, dermatitis, mental confusion, delusions of persecutions, and dementia. Sometimes, the symptoms are briefly characterized as the 3 d’s of pellagra. ( dementia, dermatitis, and diarrhea). D. Pyridoxine (B6) Present in whole grains, liver, spinach, bananas, fish, meats, nuts, potatoes. Pyridoxine is needed to use nutrients, the formation of red blood cells, and a healthy nervous system. Deficiency leads to skin disorders, anemia, and convulsions. E. Cyanocobalamine (B12) The sources are liver, kidney, milk, and cheese. It is crucial for the synthesis of DNA (deoxyribonucleic acid). It is also necessary for rapidly dividing tissues such as the hematopoietic tissue that manufactures red blood cells. Only a small amount is required in the diet, and its absence is rarely felt. However, some people cannot manufacture intrinsic factors, and the resulting inability to manufacture vitamin B12 leads to pernicious anemia. It can be corrected by giving injections of Vitamin B12 F. Ascorbic Acid (Vitamin C) Differs from the water-soluble B vitamins in that it lacks nitrogen. It is found in citrus fruits and certain vegetables such as camote tops, spinach. Green peppers, cabbage, ampalaya, potatoes, and sweet potatoes. It is necessary for maintaining intercellular proteins and for the production of hemoglobin. It is also essential in the production of dentine, cartilage, and bone. It facilitates the absorption of iron. Deficiency leads to an increase in infection susceptibility, poor wound healing, and retardation of growth. Scurvy may occur characterized by bleeding of gums, pain and tenderness, and swelling of thighs and legs. Because of its role in building the tissues and strengthening it, some people feel that Vitamin C helps protect us against cold. Inorganic Compounds/components  Include mineral elements and water, Mineral elements exist in the form of salts or combined with protein, carbohydrates, and lipids. Salts are found throughout the body- in the cell, in extra-cellular fluids, and the blood and lymph. The ions of these salts have essential roles in the proper maintenance and control of bodily functions. Table of Elements that make up the Human Body Name of Sy Percent Function/s Elements mbol age Oxygen O 65 Required for cellular respiration; present in most organic compounds; component of water Carbon C 18 Forms backbone of organic molecules; can form four bonds with other atoms Hydrogen H 10 Present in most organic compounds; component of water Nitrogen N 3 Components of all proteins and nucleic acids Calcium Ca 1.5 Structural components of bones and teeth; important in muscle contraction, conduction of nerve impulses, and blood clotting Phosphorus P 1 Component of nucleic acids; structural component of bones; important in energy transfer Potassium K 0.4 Principal positive ion (cation) within cells; important in nerve functions; affects muscle contraction Sulfur S 0.3 A component of most proteins Sodium Na 0.2 Principal positive ion in interstitial (tissue) fluid balance; essential for conduction of nerve impulse Magnesium Mg 0.1 Needed in the blood and body tissues; a component of many important enzyme systems Chlorine Cl 0.1 Principal negative ion (anion) of interstitial fluid; important in fluid balance Iron Fe Trace Component of hemoglobin, myoglobin and certain enzymes Iodine I Trace Components of thyroid hormones From Biology by Ville, Solomon, Martin, Martin, Berg and Davis Water The essential constituent of tissues and constitute about 2/3 of body weight (85-92% 0f the cell). Water is the vehicle in the body for all physiological activities that are necessary for life to take place. Life on land is possible only because terrestrial plants and animals, including man, can incorporate large amounts of water within their bodies. For a typical person, 60-70% of the weight is water. The solvent power of water is great. A great number of substances dissolve in it because it has a very high ionizing power. Water has high specific heat. This means that it can hold more heat with less temperature change than most substances; hence, the heat produced by cell metabolism makes comparatively little change in the temperature of all cells.  The heat-conducting power of water is high. This means that the heat produced in the cell can pass to body fluids even if the temperature of the cell is barely above that of the fluid around the cell, which likewise can hold this heat with comparatively little rise in temperature and pass it on with little change in temperature to the blood and finally to the skin. The latent heat of vaporization of water is high. Because of this, a maximum of heat is taken from the skin for the evaporation of perspiration. Water has high surface tension, and so many immiscible liquids it comes in contact must expose the minimum surface. But because of its excellent solvent capacity, its surface tension can be lowered by a great variety of substances. This permits the area of contact of the immiscible liquids to be.