Chapter 19 The Chemistry of Life

The Molecules of Life Many of the most important molecules in your body are polymers. 4 molecules necessary for life functions formed from smaller subunits proteins carbohydrates nucleic acids lipids

biochemistry - study of the chemistry of living things elements needed to make these molecules hydrogen oxygen carbon nitrogen phosphorous sulfur

The Role of Proteins - Catalyst - enzyme Proteins are the worker bees and have many functions Structural – keratin – hair, nails - collagen – ligaments, tendons Transport – hemoglobin Metabolism – insulin - lactase - Catalyst - enzyme

The Structure of Proteins A protein is polymer composed of amino acids bonded together in chains

Structure of Proteins amino acids bond to each other by forming a peptide bond aka protein synthesis water is released in this reaction

Three-Dimensional Protein Structure Proteins can fold into either globular structures or long, fibrous structures. The shape determines how chemical reactions take place

Three-Dimensional Protein Structure denaturation – breaking the forces that hold a protein in it’s shape high temps extreme pH mechanical agitation chemical treatments

antibodies antibodies bind to surface of invader once bound invader is destroyed binding is very specific……. your body must make different antibodies for different invaders

The Role of Proteins as Enzymes enzymes - proteins that catalyze chemical reactions—(speeds up reactions) Substrates are brought close together in the active sites of an enzyme

Carbohydrates carbohydrate – molecule that contains carbon, hydrogen, oxygen in ratio of 2 hydrogen – 1 oxygen – 1 carbon

The Role of Carbohydrates when carbohydrates break down glucose is formed glucose provides most of the energy needed for life glucose is also called blood sugar. animals store excess glucose in liver and muscles as glycogen

Structures of Carbohydrates simple sugars are 5 -7 carbon ring structure 3 common simple sugars = glucose, fructose, and ribose

Polysaccharides sucrose is table sugar = 1 glucose and 1 fructose A polymer of many monosaccharides bonded into a chain is called a polysaccharide examples: starch and cellulose

Lipids lipids are fatty acids, which are long chain carboxylic acids fat =from animals oil = from plants

The Structure of Lipids triglycerides, molecules in which three fatty acids are bonded to a glycerol

saturated fatty acids - have single bonds between carbon atoms. single bond = tightly packed = solid at room temp unsaturated - one or more double bonds between carbon atoms (healthier) double bond prevents tight packing = liquid at room temp

Fats in your diet diet high in saturated fats linked to heart disease high saturated fat = high cholesterol cholesterol lines artery walls

Steroids steroid – lipid with 4 ring structure includes hormones, vitamin D, and cholesterol

The Functions of Lipids 2 major functions of lipids store energy Form cell membranes

Nucleic Acids genetic information is coded into long-chain polymers called nucleic acids. monomers that make up nucleic acids are called nucleotides 2 types = DNA & RNA

The Structure of Nucleic Acids nucleotides are made up of three parts: a phosphate group, a five-carbon sugar, and a nitrogen base

Function of DNA & RNA DNA – holds genetic information RNA - transfers genetic info from DNA (nucleus) to place in cell where proteins are formed

Vitamins Vitamin – molecule necessary for life but needed only in small amounts 2 classes of vitamins fat-soluble – vitamins A, D, E, and K water soluble – vitamins B and C

How can I get too much vitamins? excess water - soluble vitamins are dissolved in urine and excreted out – you can’t get too much excess fat- soluble vitamins are stored in body fat – be careful you don’t take too much