IPS: Chemistry Review §Atom- basic unit of matter §Protons- positive charge, located in the nucleus §Neutrons- neutral, located in the nucleus §Electrons- negative charge, located outside the nucleus

IPS - Chemistry Review §Element- made of only one kind of atom. The number of protons determines what the element is called. In an atom, the number of protons and electrons are equal. §The same element will always have a set number of protons. §The number of neutrons may vary. These are called isotopes. §Electrons may also vary. These are called ions.

IPS - Chemistry Review §The ion is determined by the number of electrons in the outer shell or orbit. These are called valence electrons. § If an atom gains electrons, it becomes negatively charged. §If an atom loses electrons, it becomes positively charged.

IPS - Chemistry Review Bonds- joining two or more atoms together Ionic bond- formed by joining two ions together Co-Valent bond- formed by the sharing of electrons Example: NaCl Example: C 6 H 12 O 6

Macromolecules: Carbohydrates The ratio of hydrogen to oxygen is 2:1

Carbohydrates Sugar- manufactured in green plants. Provides the basic fuel for both plant and animal life.

Carbohydrates

Sugar Monosaccharides - simple sugars that may contain 5 or 6 carbon atoms. Examples: Glucose, Fructose, Galactose These simple sugars are made in plant cells. They have the same empirical or molecular formula: C 6 H 12 O 6. Their structural formulas are different.

Monosaccharides Glucose Galactose Fructose

Monosaccharides Structural formulas allow you to visualize the molecule. Notice, even though these molecules all have the same number of each atom, they look different. Holt, Modern Biology

Disaccharides §DisaccharidesDi = two §Two simple sugars form one molecule of a double sugar. One molecule of water is given off. This is called a dehydration synthesis reaction. §De = away §hydro = water §synthesis = put together

Disaccharides Maltose Sucrose Lactose

Disaccharides Glucose + glucose maltose + water C 6 H 12 O 6 + C 6 H 12 O 6 C 12 H 22 O 11 + H 2 O Dehydration synthesis- take away water to put a molecule together Holt, Modern Biology

Disaccharides Glucose + fructose sucrose + water C 6 H 12 O 6 + C 6 H 12 O 6 C 12 H 22 O 11 + H 2 O Sucrose is common table sugar. It is found in sugar cane and sugar beets. Dehydration synthesis- take away water to put a molecule together

Dehydration Synthesis Prentice Hall, Biology

Disaccharides Lactose is milk sugar, found in the milk of mammals. C 6 H 12 O 6 + C 6 H 12 O 6 C 12 H 22 O 11 + H 2 O Glucose + galactose lactose + water Dehydration synthesis- take away water to put a molecule together

Disaccharides Can these reactions be reversed to break the disaccharide apart into two monosaccharides? Yes. What must be added? What is the process called? Water must be added. The process is called hydrolysis. Hydro = waterlysis = break apart or to break down

Disaccharides This is an example of Hydrolysis. Water is added to maltose in order to break it down into two glucose molecules. Of course, enzymes would control this process. Holt, Modern Biology

Hydrolysis Prentice Hall, Biology

Polysaccharides §Polysaccharides are large molecules formed by joining monosaccharides. §Poly = many

Carbohydrates: Starch §Starch is a polysaccharide made up of glucose units in branched chains. §Each time a glucose molecule is added, one water molecule is removed (dehydration synthesis). § There may be 500 to many thousands of glucose molecules joined to form a starch molecule. §Examples: potatoes,corn, rice, wheat, and other grains.

Carbohydrates: Cellulose §Cellulose is a large polysaccharide made of chains of glucose molecules. § It may contain as many as 3,000 glucose molecules. §Cellulose forms a strong fibrous structure in plant cell walls. It gives the walls support.