1. Chapter 6
Chemistry of Life

2. Elements Approximately 115 are known to exist
Only 25 are essential for living things
4 elements make up 96% of the human body:
Carbon
Hydrogen
Oxygen
Nitrogen

3. Atoms
Smallest particle of an element that has the element’s characteristics
Basic building block of matter
Has a nucleus with protons (+) and neutrons (no charge) and an electron cloud (-).

5. Atomic number tells you number of protons and electrons
Atomic mass is determined by the number of protons and neutrons added together

6. Determining Number of Protons, Electrons, & Neutrons

7. Isotopes
Atoms of the same element that have different numbers of neutrons
Example: C-14, C-12, C-13
Used to date fossils, diagnose or treat disease

8. Compounds
Substance composed of two or more elements in definite proportions
Examples: NaCl, H2O
Created through bonding

9. Ionic Bonding
When electrons are transferred from one atom to another in order to achieve stability.
Creates one atom that has a positive charge and one that has a negative charge
The opposite charges cause the atoms to be attracted to each other.

10. Ionic Bond

11. Covalent Bonding
Atoms share pairs of electrons in order to reach stable outer energy levels.
The shared pair(s) keep the molecule together

12. Covalent Bonding

13. Chemical Reactions Occur when bonds are formed or broken
Reactants  Products
2H2 + O2  2H2O

14. Acids & Bases pH – measure of how acidic or basic something is
Scale ranges from 1(acid)-14(base)
7 is neutral

15. Carbohydrates Made of carbon, hydrogen, and oxygen
Ratio of H:O is 2:1 2 Hydrogen : 1 Oxygen
C6H12O6

16. Carbohydrates Continued
Monosaccharide – single, simple sugars
Glucose and fructose
Disaccharide – double sugar
Lactose and sucrose
Polysaccharide – large sugar
Starch and glycogen
Important for energy and making cell parts

17. Lipids Made of carbon, hydrogen, and oxygen
Ratio of H:O is much greater than 2:1

18. Lipids Continued Important for: Fats, waxes, and oils Energy storage
Insulation
Cell membranes
Fats, waxes, and oils

19. Proteins
Made of carbon, hydrogen, oxygen, and NITROGEN

20. Proteins Continued Made from subunits called amino acids
Important for:
Tissue structure
Muscle contracting
Transporting oxygen
Immunity
Enzymes

21. Nucleic Acids Biomolecule that stores cellular information in a code
Made of subunits called nucleotides
Contain carbon, hydrogen, nitrogen, oxygen, and phosphorus
Made of a sugar, phosphate group, and a nitrogenous base
Examples: Deoxyribonucleic Acid and Ribonucleic Acid