Molecules of Life Biology A

Biochemistry Terms Organic Compounds – Carbon containing compounds produced by living organisms. Macromolecule – when smaller molecules join together to form a larger more complex molecule.

Important Macromolecules There are four types of macromolecules that make up all living organisms:

1) Carbohydrates Organic macromolecules composed of carbon, hydrogen, and oxygen in a ratio of 1carbon, 2 hydrogen, and 1 oxygen. (i.e. CH2O, C6H12O6, etc.) Carbohydrates are great sources of energy because their bonds store lots of energy.

i) Simple Simple = Monosaccharides (C6H12O6) Glucose from a plant Fructose from fruits on a plant Galactose from milk Glucose Fructose

ii) Complex Complex = Disaccharides (C12H24O12) Sucrose (table sugar) = glucose & fructose Lactose (milk sugar) = glucose & galactose Maltose (malt sugar) = glucose & glucose Sucrose Lactose

iii) Very Complex Very Complex = Polysaccharides (CxHyOx) Starch is stored in parts of plants like grains & potatoes (hundreds of glucose) Cellulose is found in plant cell walls & wood Glycogen is stored in animal livers & muscles (thousands of glucose) Cellulose

2) Lipids Organic macromolecules that are not soluble (do not dissolve) in water and are useful for storing energy. Also used for making cell membranes. Lipids are better for storing energy because they contain a lot more bonds than do carbohydrates.

Lipid Types There are three basic types of lipids: Fats, Oils = energy storage Steroids = hormones & cholesterol Waxes = protective coatings

i) Two Types of Fats Saturated – most carbon atoms are bonded to two hydrogen atoms. Mostly solids like butter, lard, grease Can lead to heart disease

i) Two Types of Fats Unsaturated – most carbon atoms are bonded to one hydrogen atom. Mostly liquids like corn oil, olive oil, fish oil Usually a healthier alternative

ii) Steroids Organic macromolecules composed of four carbon rings. Found in hormones (increase cell growth), nerve tissues, and plant poisons.

iii) Waxes Organic macromolecules that serves as a protective coating and is waterproof. Plants have a thin layer on their leaves Animals produce earwax

iii) Waxes Some lipids, called phospholipids, make up the membranes of cells because they are good at keeping water separate.

3) Proteins Organic macromolecules that are the building blocks of cells (muscles, skin, blood, etc.) and enzymes. Contain Nitrogen as well as C, H, O Our bodies contain thousands of different proteins. Proteins are made of very long chains of amino acids put together like beads on a necklace.

Generalized Amino Acid There are 20 different types of amino acids and they can form new proteins based upon their order and the number of them present in a protein chain. Generalized Amino Acid

Enzymes Enzymes are SPECIAL PROTEINS that help control chemical reactions by acting as catalysts. Catalysts can speed up some reactions by more than a billion fold. Not used up in the reaction. Enzymes work by a physical fit (Lock and Key) between the enzyme and the substrate. When connected the enzyme lowers the activation energy needed for the chemical reaction.

Nucleic Acids

4) Nucleic Acids Organic macromolecules that are used to control an organisms genetic or heredity information. Nucleic acids are made up of very long chains of nucleotides.

i) Types of Nucleic Acids There are two types of nucleic acids: DNA (deoxyribonucleic acid) directs all cell activities and codes for genes RNA (ribonucleic acid) directs proteins creation and transfers information

Acids & Bases

Our Goals To determine the difference between Acids & Bases To identify the characteristics of Acids & Bases Perform an experiment dealing with Acids & Bases

What is the pH scale? The pH scale measures how acidic or basic a solution is.

The pH scale The pH scale is the concentration of hydrogen ions in a given substance.

Identifying Acids and Bases Acids have a ph from 0-7 Lower pH value indicates a stronger acid. Bases have a pH from 7-14 Higher pH value indicates a stronger base.

Definitions of Acids and Bases An acid is a substance that breaks into ions in an aqueous (water) solution. A Base (alkaline) is a substance that breaks into ions in an aqueous (water) solution.

Did we Miss something?? What happens when the pH of a substance is 7? Ans: A pH level of 7 indicates a Neutral Substance i.e: Water!

Test Your Knowledge What is the range of an ACID on the pH scale? Ans: 0-7 What is the range of a BASE and what is another name for a BASE? Ans: 7-14, Alkaline

Characteristics Of Acids Acids can be characterized by: A sour taste. It turns blue litmus paper red It tastes sour. Try drinking lemon juice (citric acid)

Characteristics of Bases A Base is characterized by: A bitter taste. (Milk of Magnesia) It feels slippery. (Soapy Water) It turns Red Litmus Blue.

Any Questions? “If we were meant to talk more than listen, we would have two mouths and one ear.” --Mark Twain “There is nothing so captivating as new knowledge.” --Peter Latham