Acids, Bases, and pH • The pH scale: Chemist devised a measurement system called the pH scale to indicate the concentration of H+ ions in a solution.
Acids • Acidic solutions contain higher concentrations of H+ ions that pure water and have a pH value below 7 • Strong acids tend to have pH values that range from 1 to 3. • The hydrochloric acid produced by the stomach to help digest food is a strong acid.
Bases • A base is a compound that produces hydroxide ions (OH-) in solution • Basic, or alkaline, solutions contain lower concentrations of H+ ions than pure water and have pH values above 7 • Ammonium is a strong base
Buffers • The pH of the fluids inside human cells must be kept between 6.5 and 7.5. If the pH is lower or higher, it will affect the chemical reactions that take place with cells. • Buffers are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH • Easy Balance?
Carbon Compounds • Carbon is so interesting that a whole branch of chemistry is set aside just to study carbon compounds. (Organic chemistry) • Carbon has 4 valence electrons • Carbon can also bond with another carbon atom!!! • No other element comes close to matching carbons versatility…
Macromolecules (biomolecules) • Many of the molecules of living cells are so large that they are known as macromolecules (giant molecule) • There are four groups of macromolecules in living things • Carbohydrates • Lipids • Nucleic acids • Proteins
Carbohydrates (Carbs) • Carbohydrates are compounds made-up of carbon, hydrogen and oxygen usually in the ratio of 1:2:1 • Living things use carbs as their main source of energy. • Single sugar molecules: monosaccharides • Monosaccharides form polysaccharides
Lipids • Lipids are made mostly from carbon and hydrogen atoms • Lipids are used to store energy • Steroids are derived from lipids called cholesterol. • The common groups of lipids are • Fats • Oils • Waxes
Nucleic Acids (DNA & RNA) • Nucleic acids are macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus. • Nucleic acids are polymers assembled from monomers known as nucleotides. • Nucleotides • Sugar • Phosphate • Nitrogenous base
Nucleic Acids (DNA & RNA) • Nucleic acids store and transmit hereditary, or genetic information. • There are two kinds of nucleic acids: • RNA (Ribonucleic acid) • DNA (Deoxyribonucleic acid)
Proteins • Proteins are polymers of monomers called amino acids • There are 20 amino acids • About 10 are essential and must be consumed in the foods we eat in order to be healthy!!! • Vegetarians?
Proteins • Some proteins control the rate of reactions and regulate cell processes • Some form bone and muscle • Others work as doors or elevators that transport substances into or out of cells. • Enzyme: insulin???