Chapter Six: Chemistry in Biology

1. Chapter Six: Chemistry in Biology 6.1 Atoms, Elements, and Compounds 6.2 Chemical Reactions 6.2 Water and Solutions 6.4 The Building Blocks of Life

2. 6.1 Atoms, Elements, and Compounds • The building blocks of matter are __________. They are the smallest unit of matter. • Composed of three _____________ particles. • _______________: positively charged particles. • _______________: neutral particles • _______________: negatively charged particles. • The protons and neutrons are contained in the ______________.

3. Elements & Periodic Table • Pure substances that cannot be broken down into other substances by _____________ or _____________ means. • Periodic table consists of rows, called _____________, and columns, called _____________. • Atoms of the same element that have a different number of neutrons are known as _______________. • Carbon-14 is an example of a _______________ ____________.

4. Compounds • A pure substance formed when two or more different elements combine are called ________________. • Water is ________. • Sodium chloride is _______. • Methane is ____________. • Compounds cannot be broken down into simpler compounds or elements by _____________ means.

5. Chemical Bonds • Electrons are shared in _______________ bonds. • A ____________ is a compound in which the atoms are held together by covalent bonds. • Single, double, and ___________ bonds can exist in covalent molecules. • H2, O2, and N2 are examples of each • Electrons are either taken or given in _________ bonds. • When an atom gains or loses an electron, it becomes an ________.

6. Trends on the Periodic Table • Donators are on the __________. • Acceptors are on the ____________.

7. Van der Waals Forces • The attractions between molecules that hold them together. • Strength of the attraction dependents on three things. • ________ • ___________ • Ability to attract ___________. • van der Waals forces allow water to form droplets.

8. 6.2 Chemical Reactions • Process by which ________ or groups of atoms in substances are ___________ into different substances. • Iron oxide is also known as _________, and is formed when iron reacts with oxygen. • Signs of a chemical reaction include: • Production of _________ or light • Formation of a _________ or ____________.

9. Chemical Equations • Reactants  Products • The arrow can mean _________ or ________________. • Reactants are the ______________ substances. • Products are the substances formed during the reaction. • C6H12O6 + O2  CO2 + H2O • Anyone know what this reaction is? • Now we have to balance it!

10. Balancing an Equation • C6H12O6 + O2  CO2 + H2O • Carbons: Carbons: • Hydrogens: Hydrogens: • Oxygens: Oxygens:

11. Activation Energy • The minimum amount of energy required to make the reactants become products • Example: you must light the wick of a candle before the candle will burn. • What is the change in energy? Exothermic: ___________ Endothermic:___________

12. Enzymes • Help ___________ the activation energy of a reaction. • A ____________ is a substance that lowers the activation energy needed to start a chemical reaction. • Enzymes are _____________ catalysts.