CHAPTER 6 REVIEW
Monday, December 11th Use the Ch 6 powerpoint found on my website to answer the following:
1. An atom of carbon contains 6 protons. How many electrons would its second energy level have?
2. What makes water an excellent solvent? 3. What are the 4 biomolecules of life? Give an
example of each, along with each of their monomers.
Acids & Bases
• Acid: – Any substance that releases a hydrogen
ion (H+) in water. – pH below 7
• Base: – Any substance that combines with
hydrogen ions in water. – pH above 7
pH Scale
Vocabulary
• Element: – A substance that can’t be broken down into
simpler chemical substances • Atom:
– Basic building blocks of all matter. • Nucleus:
– The center of an atom. Comprised of protons and neutrons.
Structure of Atoms
• Atoms are the smallest units of matter that retain the properties of an element
• Atoms consist of 3 types of subatomic particles – protons, neutrons and electrons
• Nucleus contains protons (p+) & neutrons (neutral charge)
• Electrons (e-) surround the nucleus as cloud
Electron Shells • Each electron shell can hold only
a limited number of electrons – first shell can hold only 2 electrons – 2nd shell can hold 8 electrons – 3rd shell can hold 18 electrons – higher shells (up to 7) hold many more electrons
• Number of electrons = number of protons • Each atom is electrically neutral; charge = 0
Ionic Bonds
• Positively and negatively charged ions attract each other to form an ionic bond
Covalent Bonds • Atoms share electrons to
form covalent bonds
Polar Covalent Bonds • Unequal sharing of electrons between atoms. • In a water molecule, oxygen attracts the
electrons stronger than hydrogen (Water= polar)
Water • Most important inorganic compound in living
systems • Medium of nearly all chemical reactions • Polarity
– uneven sharing of electrons – partial negative charge near oxygen atom and
partial positive charge near hydrogen atoms • makes it an excellent solvent (dissolver) • gives water molecules cohesion
Compounds and Molecules
• A molecule is formed when two or more atoms join together chemically.
• A compound is a molecule that contains at least two different elements.
• All compounds are molecules but not all molecules are compounds.
What are organic molecules?
• Contains Carbon • Biomolecules = the important organic molecules for life, the building blocks of living things
Organic Compounds
• contain carbons and hydrogen • 4 types of organic compounds:
– 1. Carbohydrates – 2. Lipids – 3. Proteins – 4. Nucleic Acids
Carbohydrates
• Elements: Carbon, Hydrogen, Oxygen
• Examples: Sugars, Starch, Cellulose
• Function: Supplies energy for cell, Plant structures, Short term energy
• Monomer: monosaccharide
Lipids
• Elements: Carbon, Hydrogen, Oxygen, Phosphorus
• Examples: Fats, Oils, Waxes, Cholesterol, Phospholipids
• Function: Stores large amounts of energy, Protection, Boundaries
• Monomer: fatty acid, glycerol
Lipids
• Subunits: • Glycerol • FaCy Acid
Proteins • Elements: Carbon, Hydrogen, Oxygen,
Nitrogen, and Sulfur • Examples: Enzymes, Skin, Hair • Function: Regulates cell processes,
Build cell structures • Monomer: amino acids bonded
together by peptide bonds
Nucleic Acids
• Elements: Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorous
• Examples: DNA and RNA • Function: Carry hereditary
information, Makes proteins
Enzymes • Enzymes are protein molecules that act as
catalysts (speed up chemical reactions) • Enzymes usually end in suffix -ase and are named
for the types of chemical reactions they catalyze