The Chemistry of Life

Ch 6

Atoms & Their Interaction

• Atoms are the basic building blocks of all matter.

Atoms

• Consist of a nucleus containing protons & usually neutrons. The positively charged nucleus is surrounded by rapidly moving, negatively charged electrons.

Stability

• Atoms become stable by bonding to other atoms through covalent or ionic bonds.

Mixture vs. Solution

• Components of mixtures retain their properties

• Solutions are mixtures in which the components are evenly distributed

Acids & Bases

• Acids are substances that form hydrogen ions in water. Bases are substances that form hydroxide ions in water.

ExamplesAcids Bases

Water & Diffusion

• Water is the most abundant compound in living things.

• Water is an excellent solvent due to the polar property of its molecules.

• Particles of matter are in constant motion.

Diffusion occurs from areas of higher concentration to areas of lower

concentration.•

3 key factors affect the rate of diffusion:

• Concentration - primary controlling factor!(The more concentrated the substances the more rapidly diffusion occurs due to more collisions between particles.)

• Temperature - (An increase in temperature increases energy and causes what to happen?)

• Pressure - (An increase in pressure accelerates particle motion and what will happen?)

Carbon

• All organic compounds contain carbon atoms.

Looking for carbon-based life forms…

There are 4 principal types of organic compounds, or biomolecules, that make up

living things:

• Carbohydrates

• Lipids

• Proteins

• Nucleic acids

Carbohydrates can be categorized by the following:

• Monosaccharide is the simplest form of a carbohydrate. It is a simple sugar

• Ex. Glucose and fructose

• Disaccharide is the combination of two monosaccharide sugars. When glucose and fructose are Chemically combined sucrose (table sugar) is formed

• Polysaccharides are the largest carbohydrate molecules

There are 3 major types of polysaccharides:

• starch – energy storage by plants and as food in seeds and bulbs

• glycogen – energy storage in livers of mammals

• cellulose – forms the cell wall of plants and gives structural support

Lipids

• are very important for the proper functioning of organisms.

• Cells use lipids for energy storage, insulation and protective covering.

• Examples of lipids are: oils, waxes, steroids

Proteins: • The basic building blocks of proteins are amino

acids.

• Proteins are important in the contracting of muscle tissue, transporting oxygen, in the blood stream, providing immunity and regulating other proteins.

• Enzymes are important proteins found in living things.

Enzymes-

• a protein that changes the rate of a chemical reaction. It can increase the speed of the reaction.

• The rate of enzyme activity depends on:

• Temperature

• Ionic conditions

• pH of environment

Nucleic Acids:

• Complex biomolecule that stores cellular information in the form of a code.

• Nucleic Acids are polymers made of smaller subunits called nucleotides

The structure of a biomolecule will help determine its properties

and functions.