Chapter 2 Chemistry of Life

Question 1

basic unit of matter

Answer 1

atom

Question 2

pure substances composed of only one of more than a hundred types of atoms that exist in nature

Answer 2

element

Question 3

particles of matter that are composed of several kinds of one or mores atoms

Answer 3

molecule

Question 4

substances whose molecules have more than one element in them

Answer 4

compound

Question 5

Describe the structure of an atom

Answer 5

The nucleus-protons (+) and neutrons (-) is at the core. Electrons inhabit outer energy levels called energy levels. The number of protons determine what kind of atom it is. For example, a carbon atom only has six protons.

Question 6

Compare and contrast the different kinds of bonding. (Ionic covalent and hydrogen bonds)

Answer 6

An ionic bond forms between an atom that has only one or two electrons in the outermost level (that would normally hold eight) and an atom that needs only one or two electrons to fill its outer level.
Covalent bonds are when atoms share electrons. These bonds are not easily broken and do not break apart in water.
Hydrogen bonds are a weak attraction that holds substances together. Hydrogen bonds do not form new molecules.

Question 7

Distinguish between organic and inorganic chemical compounds

Answer 7

Organic compounds are composed of molecules that contain C-C covalent bonds, C-H covalent bonds or both.
Few inorganic compounds have carbon atoms in them.

Question 8

Discuss the chemical characteristics of water

Answer 8

Water is an inorganic compound. Water molecules form temporary attachments (hydrogen bonds) that give liquid water its slightly gluelike properties.

Question 9

Explain the concept of pH

Answer 9

The H+ concentration is balanced with the OH- concentration at pH 7. At values above 7 (low H+), the scale tips in the basic direction. At values below 7 (high H+), the scale tips toward the acid side.

Question 10

Discuss the structure and function of the following types of organic molecules: carbohydrate, lipid, protein, and nucleic acid

Answer 10

Carbohydrate are made up of carbon and water atoms. Monosaccharides (examples are glucose,galactose, fructose) are used as a source of energy and used to build other carbohydrates. Disaccharides (examples are sucrose, lactose, maltose) can be broken into monosaccharides. Polysaccharides (examples are glycogen, starch) used to store monosaccharides (thus to store energy)

Lipids are fats and oils. Triglycerides are composed of one glycerol and three fatty acids that store energy. Phospholipids contain phosphorus units and two fatty acids that form cell membranes. Cholesterol have four carbon rings at the core and transports lipids.

Nucleic acids are DNA and RNA. DNA is the double helix. RNA is a working copy of a portion of DNA.