Chapter Six: Chemistry in Biology

6.1 Atoms, Elements, and Compounds6.2 Chemical Reactions6.2 Water and Solutions6.4 The Building Blocks of Life

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 ______________.

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 _______________ ____________.

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.

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

________.

Trends on the Periodic Table

Donators are on the __________. Acceptors are on the ____________.

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.

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 ____________.

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!

Balancing an Equation

C6H12O6 + O2 CO2 + H2O

Carbons: Carbons: Hydrogens: Hydrogens: Oxygens: Oxygens:

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:___________

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.