General Biology I: Lesson 5 - The Chemical Basis of Life PDF

LESSON 5: THE CHEMICAL BASIS OF LIFE General Biology I  ORGANIC COMPOUNDS All living organisms are made up of hydrogen, oxygen, nitrogen and carbon 99% of the weight of living things is composed of this atoms Have carbon atoms that are bonded together with hy...

LESSON 5: THE CHEMICAL BASIS OF LIFE General Biology I  ORGANIC COMPOUNDS All living organisms are made up of hydrogen, oxygen, nitrogen and carbon 99% of the weight of living things is composed of this atoms Have carbon atoms that are bonded together with hydrogen  ORGANIC COMPOUNDS 1. PROTEINS 2. ENZYMES 3. NUCLEIC ACID ( RNA and DNA) 4. CARBOHYDRATES 5. LIPIDS ESSENTIAL ELEMENTS IN THE BODY  PROTEINS (CHON) Most abundant organic compounds in living cell. Fundamental constituents of the cell protoplasm FUNCTIONS: 1. Essential in building and repairing of body cells and tissues 2. Most enzymes are CHONs, and they aid in speeding up the building and repairing of almost tissues. 3. Proteins bring about individual differences. Individuals has a unique CHON make up. 4. Protein serve as transport molecules, it reserves food and provides protection as antibodies. AMINO ACID ( BUILDING BLOCKS OF PROTEINS)  ENZYMES Special proteins that are catalytic in action Speeds up or hasten chemical reactions without being directly used up in the reaction Example: Starch Water Simple Sugar ( 30 minutes, under high temperature under acidic conditions) vs. Starch Salivary Amylase Simple Sugar ( 3 minutes under room temperature, under non acidic condition)  NUCLEIC ACID ( RNA and DNA) Large complex organic molecules composed of the elements carbon, oxygen, nitrogen and phosphorus STRUCTURE DNA RNA Sugar Deoxyribose Ribose Nitrogenous Adenine, Adenine, Bases Guanine, Guanine, Thymine, Uracil Cystosine Cystosine Strands Double Single Stranded Stranded Helix Yes No  ROLES OF NUCLEIC ACID IN LIVING THINGS DNA serves as genetic material of all living things Provides the instruction in making CHON and enzymes in living system Determines what kind of CHON should be synthesized by an organism which then determine specific characteristics of an organism RNA is synthesized from DNA and is responsible for CHON synthesis DNA and RNA control the organization of enzymes which determine all chemical activities and reactions of the cell  CARBOHYDRATES Organic compounds consisting of Carbon, Hydrogen and Oxygen where the proportions is two to one that is C(H 2O) Chief energy sources in all organisms  ROLE OF CARBOHYDRATES Source as backbone of other molecules Serves as stored energy ( starch, cellulose, glycogen) Most common source of energy in the body Combines with CHON (glycoproteins) to form structural components of cell CLASSIFICATION OF CARBOHYDRATES  MONOSACCHARIDE Simple sugar compound of only one sugar molecule Building blocks of more complex forms of sugars a. Glucose (dextrose) b. Galactose (part of lactose- milk sugar) c. Fructose (corn sugar, the sweetest sugar)  DISACCHARIDES Composed of two monosaccharide molecules Hydrolysis- utilization in small intestine during digestion yielding monosaccharide units a. Sucrose ( Glucose and Fructose) b. Lactose (Glucose and Galactose) c. Maltose ( Malt Sugar)  POLYSACCHARIDE Complex form of carbohydrates that consist of 3 or more monosaccharide molecules a. Starch ( stored CHO in plants) b. Glycogen ( stored CHO in animals) c. Cellulose ( insoluble substance that is the main constituent of plant cell walls) d. Chitin ( a fibrous substance consisting of polysaccharides and forming the major constituent in exoskeleton of arthropods)  LIPIDS Constitute another major class of organic compounds present in living cells include fat and fatlike molecules Insoluble in water  ROLES OF LIPIDS Serve as the highest energy giving foods in the body Serve as the insulators by protecting animals from extreme cold Constituent of the protoplasm of the living cells Form a part of the structure of the cell membrane Serves as building blocks for many steroids ( cholesterol and bile salts)  FORMS OF LIPIDS 1. Fatty Acid- Fatty acids are the building blocks of the fat in our bodies and in the food we eat. During digestion, the body breaks down fats into fatty acids, which can then be absorbed into the blood. Fatty acid molecules are usually joined together in groups of three, forming a molecule called a triglyceride. 2. Phospholipid- A phospholipid is a type of lipid molecule that is the main component of the cell membrane. Lipids are molecules that include fats, waxes, and some vitamins, among others. Each phospholipid is made up of two fatty acids, a phosphate group, and a glycerol molecule. 3. Sphingolipid - Sphingolipids are a class of lipids containing a backbone of sphingoid bases, a set of aliphatic amino alcohols that includes sphingosine. 4. Waxes - Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C (104 °F), melting to give low viscosity liquids. Waxes are insoluble in water but soluble in organic, nonpolar solvents. 5. Serpens-Bacterial Wall 6. Steroids (Sex Hormones)- Steroids are lipids because they are hydrophobic and insoluble in water, but they do not resemble lipids since they have a structure composed of four fused rings. Cholesterol is the most common steroid and is the precursor to vitamin D, testosterone, estrogen, progesterone, aldosterone, cortisol, and bile salts  NEXT TOPIC: INORGANIC COMPOUNDS ( Water, Acids, Bases, Other Inorganic Elements And Compounds)