Organic Compounds Intermolecular Forces Hydrogen bonds When a hydrogen atom is covalently bonded to a highly electronegative atom like nitrogen oxygen or fluorine N O F it can exhibit an additional polar attraction This attraction is called a hydrogen bond Electronegativity The ability of an atom to attract electrons towards itself in a chemical bond The Living Cell Biochemistry Is the chemistry of liv ing things and life process The basic structural unit of all living or ganisms is the cell Plant Cell Animal Cell All cells are enclosed in a cell membrane which regulates the passage of nutrients and wastes In addition to a cell membrane plant cells are surrounded by a cell wall composed of cellulose Nucleus The nucleus contains the genetic material that controls heredity Ribosomes The structure where protein synthesis occurs Mitochrondria The cell structure where energy production occurs Chloroplasts Found only in plant cells In the chloroplasts photosynthesis occurs Energy in Biological Systems Green plants contain chloroplasts which are capable of taking the radiant energy of the sun and storing it as chemical energy in glucose molecules 6 CO2 6 H2O C6H12O6 6 O2 Plant cells can also convert carbohydrate molecules to fat molecules and some are even capable of converting them to proteins Animals cannot produce their own energy They must obtain such energy by eating plants or other animals that eat plants Animals obtain energy from 3 major types of substances 1 Carbohydrates 2 Fats 3 Proteins Energy in Biological Systems Classes of Food Foods are chemicals For proper nutrition our diet should include balanced proportions of carbohy drates fats and proteins along with water vitamins minerals and fiber Carbohydrates are polyhydroxy aldehydes or ketones or compounds that can be hy drolyzed split by water to form such compounds includes sugars starches and cellulose C6 H2O 6 usually expressed by the formula Cx H2O y i e glu cose C6H12O6 which is Sugars are sweet tasting carbohydates Monosaccharides disaccharides or polysaccharides Monosaccharides Carbohydrates that cannot be hydrolyzed into simpler compounds Disaccharides consist of molecules that can be hydrolyzed into two monosaccharide units Hydrolyzed into glucose and fructose Hydrolyzed into glucose and galactose Polysaccharides are composed of large molecules that can be hydrolyzed into many monosaccharide units Examples include starch cellulose and glycogen Carbohydrates in the Diet The monosaccharides glucose dextrose and fructose and the disaccharide sucrose are the most common dietary sugars Digestion and Metabolism of Carbohydrates Glucose and fructose are absorbed directly into the bloodstream Sucrose is hydrolyzed into glucose and fructose Sucrose H2O Glucose Fructose Lactose found in milk is hydrolyzed to glucose and galactose Lactose H2O Glucose Galactose Some people lack the enzyme necessary to hydrolyze lactose This is known as lactose intolerance Galactose is converted to glucose during metabolism Some babies lack the enzyme galactosemia necessary for this conversion and require a synthetic formula for proper nutrition Complex Carbohydrates Starch and cellulose starch are polymers of glucose connected by alpha linkages most animals and humans possess the enzymes necessary to hydrolyze starch to glu cose that can then serve as a source of energy Carbohydrates such as starch pro duce 4 kcal of energy per gram Cellulose is a polymer of glucose connected by beta linkages most animals and hu mans lack the enzymes necessary to hydrolyze cellulose and it serve as a source of roughage or dietary fiber Glycogen is the means by which animals store glucose It is a highly branched polymer of alpha glucose and is sometimes known as animal starch Excess glycogen is stored as fat Some bacteria found in the gut of termites and digestive tract of grazing animals can hy drolyze cellulose to glucose and these animals can use cellulose as a source of food