Chemistry in BiologyChapter 6.1

Biology

Intro to the ChemistryYour life DEPENDS on chemistry!

1. When you inhale oxygen, your body uses it in chemical reactions!

2. When you eat food, your body breaks it down and uses it in chemical reactions!

6.1: Atoms, Elements, and Compounds

Chemistry is the study of matter. Matter is anything that has mass and

takes up space.Atoms are the building blocks of matter.

Brain Pop -Atoms

THE STRUCTURE OF ATOMS:

Billions of atoms could fit on the head of a pin!

Atoms are made up of even smaller particles –1. Neutrons2. Protons3. Electrons

The Structure of Atoms:Nucleus – the center of an atomWithin this nucleus are protons and neutrons.

Neutrons – particles that have no chargeProtons – particles with a positive charge

Electrons – negatively charged particles located outside the nucleus.Constantly move around the nucleus in energy levels

Elements:An element is the name for a specific Atom.

It is a pure substance that cannot be broken down into other substances by chemical or physical means.

But Elements can be joined together to form compounds.

All living things are made up of chemical compounds.

• A compound is made of atoms of different elements bonded together, such as H2O or CO2.

• These compounds are the building blocks of our body and the world around us.

• The bonds that can hold compounds together are ionic, covalent, and hydrogen bonds.

3 Types of Bonds:

1. Ionic bond – forms between oppositely charged ions

2. Covalent bond – forms when atoms share a pair of electrons

3. Hydrogen bond – Type of covalent bond; forms between slightly positive hydrogen atoms and slightly negative atoms. Think WATER!

OHH

_

++

covalent bonds

Oxygen atom (O)

Carbon atom (C)

Oxygen atom (O)

Carbon dioxide (CO2 )

Sodium ion (Na+)

Chloride ion (CI-)

ionic bond

gained electron

• Ion = atom that has lost or gained electrons

Types of Compounds:1. Molecule - a compound in which the atoms are held together by covalent bonds.

2. Ionic compound – a substance formed by ionic bonds.