Chapter 2 The Chemistry of Life

CHEMISTRY The study of the composition and properties of matter and the energy transformations that accompany changes in the basic structure of matter

Anything that occupies space and has mass Matter Anything that occupies space and has mass

Matter Three states Composed of elements 5 elements are essential to life in large amounts (C, H, O, N, Ca). Table 2-1, page 33

Matter Elements combine to form compounds. Compound: a substance made up of two or more elements (e.g., H2O)

What is the common name for the compound C6H12O6? Alcohol Sugar Vinegar Salt Baking soda

Matter Elements combine to form compounds. Compounds have different properties from the elements that form them.

Matter Elements combine to form compounds. Expressed by molecular and structural formulas

Changes Chemical changes Physical changes

Energy The ability to do work

Energy Kinetic energy Energy of motion Potential energy Stored energy

Can potential energy be converted into kinetic energy? Yes No

Can kinetic energy be converted into potential energy? Yes No

Energy Changes 1st law of thermodynamics Energy is neither created nor destroyed.

Energy Changes 2nd law of thermodynamics Whenever energy is used, some of it is wasted. Law of degeneration

An increase in disorder and loss of usable energy Entropy An increase in disorder and loss of usable energy

Energy Kinetic energy Potential energy Kinetic molecular energy ALL of the molecules in matter are moving.

Energy Kinetic energy Potential energy Kinetic molecular energy Potential energy of a molecule

Chemical Reactions Endothermic Require or absorb heat Exothermic Give off heat

Chemical Reactions Activation energy The amount of energy needed to start a chemical reaction

Chemical Reactions Catalysts Affect the rate of a reaction but are not changed in the reaction

Chemical Reactions catalyst X A + B C + D

Chemical Reactions Enzymes Compounds that serve as organic catalysts

Solutions Suspensions Colloids

Solution A homogeneous mixture of one or more substances in another substance Solute (dissolved) Solvent (dissolver)

Suspension A substance in which the particles are mixed but are not dissolved and will settle out over time

Colloid A mixture of fine particles that do not dissolve but also do not settle out quickly Gel phase (semisolid) & sol phase (fluid) Reversible & nonreversible

Diffusion Net movement of molecules from an area of higher concentration to an area of lower concentration

Will diffusion eventually stop, or will it continue indefinitely? It will stop. It will continue.

Diffusion Kinetic molecular energy is the driving force behind diffusion.

Diffusion Concentration gradient Difference between the numbers of 1 type of molecule in 2 adjacent areas Diffusion pressure

The diffusion of water through a semipermeable membrane Osmosis The diffusion of water through a semipermeable membrane

Will equilibrium ever be reached in osmosis? Yes No