1. BASIC CHEMISTRY

2. Why study Chemistry in Biology? Biology - study of LIFE! Biology - study of LIFE! Chemistry - part of chemistry deals with chemical compounds…. And chemical compounds are important to living things. Chemistry - part of chemistry deals with chemical compounds…. And chemical compounds are important to living things. Ex: glucose- C 6 H 12 O 6 Ex: glucose- C 6 H 12 O 6 water - H 2 O water - H 2 O salt - NaCl salt - NaCl

3. Composition of Matter Organisms are composed of matter. Organisms are composed of matter. Matter is anything that has mass and takes up space.Matter is anything that has mass and takes up space. Matter is made up of elements, which cannot be broken down by chemical reactions.Matter is made up of elements, which cannot be broken down by chemical reactions.

4. Elements Pure substances that cannot be broken down chemically into simpler kinds of matter Pure substances that cannot be broken down chemically into simpler kinds of matter 92 naturally occurring elements, 25 of which are essential to life. 92 naturally occurring elements, 25 of which are essential to life. 96% of living matter is composed of 4 elements (CHON) 96% of living matter is composed of 4 elements (CHON) Carbon Hydrogen Oxygen Nitrogen

5. Compounds Most elements do not exist by themselves Most elements do not exist by themselves Elements combine together in a fixed ratio to form compounds. Elements combine together in a fixed ratio to form compounds. Ex. H 2 O, NaClEx. H 2 O, NaCl Compounds are held together by chemical bonds. Compounds are held together by chemical bonds. Reactivity and type of bond are determined by the number of electrons it hasReactivity and type of bond are determined by the number of electrons it has

6. The chemical bonds that are important to Biology are covalent, ionic, and hydrogen bonds. The chemical bonds that are important to Biology are covalent, ionic, and hydrogen bonds.

7. Covalent Bond (strong) The sharing of electrons between atoms thus forming a molecule (smallest unit of compounds) such as water. Each hydrogen atom shares 2 electrons with the oxygen atom. Impt. to living things Found in Biomolecules Resulting substance is stable, and is referred to as a molecule.

8. Ionic Bonding Formed between two atoms when one atom loses an electron, and the other atom gains an electron. Formed between two atoms when one atom loses an electron, and the other atom gains an electron. This giving & receiving results in charged particles known as ions - they have an uneven # of protons and electrons. This giving & receiving results in charged particles known as ions - they have an uneven # of protons and electrons.

9. Hydrogen Bonds (weak) A single water molecule can form as many as 4 hydrogen bonds at the same time. Occurs when H+ (which is already bonded to an electronegative atom) is ATTRACTED to another electronegative atom. Occurs when H+ (which is already bonded to an electronegative atom) is ATTRACTED to another electronegative atom.. Very weak bond Occurs between molecules, not elements. Important in DNA, water.