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