Biomolecules are organic molecules produced by living organisms which consists mainly of the following elements:

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2 Biomolecules are organic molecules produced by living organisms which consists mainly of the following elements: These elements are non-metals which combine in various ways to form biomolecules through a covalent type of bonding.

3 A wide range of biomolecules exist, including large molecules known as macromolecules and small molecules known as micromolecules. Biomolecules are categorized into four classes.

4 Biomole cule Element Content Exampl e Building Block Carbohydrate Protein Carbon, Hydrogen, Oxygen Carbon, Hydrogen, Oxygen, Nitrogen, Sulfur polysaccha ride Polypeptid e monosacchar ide amino acid They are polymers of repeating units of smaller molecules called monomers. Lipid Nucleic Acid Carbon, Hydrogen, Oxygen Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous Triglyceri de DNA/RNA glycerol and fatty acid nucleotide Through a covalent type of bonding, these monomers create various forms of each organic molecule.

5 Physiological functions rely on energy can be provided by Carbohydrates Lipids are classified as Monosaccharides Disaccharides Polysaccharides composed of Carbon Hydrogen Oxygen are classified as Triglycerides (fats & oils) Phospolipids Steroids (Cholesterol) Waxes

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7 The most abundant class of biomolecules A chief source of energy of almost all living organisms Originated from the French word hydrate de carbone, which means hydrates of carbon Sometimes called saccharides, from the Greek word sakcharon, meaning sugar The suffix ose is used to denote the name of a saccharide Food that are high in carbohydrates include: FRUITS SWEETS RICE BREAD AND PASTA BEANS AND POTATOES

8 Contain the elements carbon, hydrogen and oxygen They have an C:H:O ratio of 1:2:1 based on their general formula C n (H 2 O) n Carbohydrates include sugars, starches, cellulose, and many other compounds in organisms They are either formed from or decomposed into other carbohydrate forms through the physiological processes in plants and animals Example: THROUGH THE PROCESS OF PHOTOSYNTHESIS CO 2 and H 2 O to form the sugar, glucose.

9 Primary functions of carbohydrates in living organisms: Substrate for respiration Source of energy Intermediate substances in respiration (glyceraldehydes) Energy storage (starch and glycogen) Structure (chitin in arthropod exoskeleton and fungal walls) Transport (sucrose transported in the phloem of a plant) Recognition of molecules that pass through the cell membrane

10 FISCHER PROJECTION (CHAIN FORM) HAWORTH PROJECTION (RING FORM) GLUCOSE

11 MONOSACCHARIDES Simplest carbohydrates Most basic unit of a carbohydrate Also know as simple sugars Only sugars that can be absorbed and utilized by the body At room temperature: crystalline white solids All carbon atoms have OH groups in their molecular structure except one which has an aldehyde (-CHO) or ketone (-CO) group Polar and very soluble in water

12 Name of monosac charide Derivation of Name Source Ring Formula Glucose Galactos e Fructose Greek word Gleukos sweet wine Greek word Galact milk Latin word Fructus fruit (also known as levulose) Grape sugar, blood sugar, dextrose Component of lactose in milk Fruits, honey, sweetest sugar

13 ALDOSE if it contains an aldehyde group (-CHO) KETOSE if it contains a ketone group (-CO) NUMBER OF CARBON ATOM (Ex. C 3 triose; C 4 -tetrose; C 5 - pentose; C 6 -hexose; C 7 - heptose; C 8 -octose; C 9 -nonose) Simplest monosaccharides: triose glyceraldehyde & dihydroxyacetone ISOMERS

14 DISACCHARIDES Made up of two monosaccharide units Joined by a GLYCOSIDIC BOND (type of covalent bond that links a carbohydrate unit to another) Has a molecular formula of C 12 H 22 O 11 Cannot be directly utilized by the body unless broken down into monosaccharides + H 2 O Condensation & hydrolysis of SUCROSE

15 SUCRALOSE is an artificial sweetener made from sugar but contains NO CALORIES. Derived from Cane sugar (sucrose) Three hydroxyl groups are replaced with CHLORINE atoms. Chemically inert and is NOT broken down to its component monosaccharides, glucose & fructose. NOT METABOLIZED; it yields NO CALORIES and passes through and out of the body unchanged.

16 Name of Disacchari de Derivation of Name Source Ring Formula SUCROSE (glucose + fructose) French word Sucre - sugar Table sugar, cane sugar, beet sugar LACTOSE (glucose + galactose) Latin word Lact - milk milk MALTOSE (glucose + glucose) Old English mea lt - malt Germinating grains; Used in making BEER

17 POLYSACCHARIDES Composed of a long chain of monosaccharide units (10 or more) Also called POLYMERS ( poly - many; mers monomers) High molecular mass Glucose is the repeating monomer unit Only differ in the number of glucose units, the extent of branching & the position of the glycosidic bonds Two types: 1) Homopolysaccharides (formed by the same type of monosaccharides) Ex. Starch, glycogen, cellulose 2) Heteropolysaccharides (formed by different type of monosaccharides) Ex. glycosamines, peptidoglycans

18 Name of Polysaccharid e STARCH CELLULOSE Source Stored form of glucose in PLANTS Cereals (wheat; rice) Tubers (Potatoes) Rigid cell walls in plants Ring Formula GLYCOGEN Stored in the form of glucose in ANIMALS &

19 GLYCOSIDIC BONDS (STARCH & CELLULOSE)

20 GLYCOSIDIC BONDS (GLYCOGEN)

21 Thousands of glucose cellulose molecule (which constitutes the structural framework of plants) Glucose may fuse = STARCH (seeds and serve as food for a growing plant) Animals and humans eat cellulose or starch broken down to glucose units carried by the blood to the liver recombined to form glycogen (animal starch) stored If the body needs energy glycogen is broken down to glucose then transferred to the tissues were it is oxidized to carbon dioxide and water. Some of the glucose fats Some react with nitrogen-containing compounds amino acids (which in turn are combined to manufacture proteins)