1. THE CHEMICAL BASIS OF THE BODY

2. The Composition of Matter
Matter- the stuff of life
Atom- smallest unit of matter that has specific properties
Molecules- combination of 2 or more atoms
ex: H + H H2
Compounds- combination of 2 or more different atoms
ex: H + H + O H20

3. Atomic Structure Nucleus Electron Shell Protons (+ charge)
Neutrons (no charge)
Electron Shell
Electrons (negative charge)

4. Atomic Structure (Continued)
Isotopes- atoms of the same element with different numbers of neutrons.
Atomic Weight- average mass of an atom.

5. Chemical Bonds & Chemical Compounds
Ionic Bonds-anions and cations are held together by the attraction of negative and positive charges.
Covalent Bonds-atoms held together by the sharing of electrons.
Hydrogen Bonds-attraction between hydrogen and a negatively charged particle.

6. 3 Types of Chemical Reactions:
Synthesis-chemically combining two molecules
A+B AB
Decomposition- breaking large molecules into smaller molecules
AB A + B

7. Exchange Reactions- molecules are shuffled around.
AB + CD AD + CB

8. Examples Synthesis- glycerol + 3 fatty acids -------> fat
Decomposition- glucose > carbon dioxide water
Exchange Reaction- NaOH + HCl ---- NaCl + H2O

9. Reversible Reactions A + B ------- AB AB --------- A + B
Na + OH NaOH
HCl------ H + Cl

10. pH and Buffers pH-Concentration of hydrogen atoms
Buffers-compounds that stabilize pH by removing or replacing hydrogen atoms.

11. Inorganic Compounds
Inorganic compounds- do not contain carbon & hydrogen atoms together They are held together by ionic bonds
Examples:
Water
Salts
Acids and Bases

12. Water Makes up 60-70 % of a cells mass Universal solvent
Released by cells to reduce friction between body parts
Important transport medium
Has a high heat capacity

13. Acids & Bases
Acid- molecule that releases one or more hydrogen ions when ionized in water
ex: HCl is a strong acid
Base- molecule that reduces a concentration of hydrogen ions in the solution
ex: NaOH is a strong base

14. Organic Compounds- building blocks of most living structures
Carbohydrates
Lipids
Proteins
Nucleic Acids
ATP

15. Carbohydrates Contain: C, H, O Sugars and starches
Energy source to fuel body activities
3 types:
Monosaccharides- simple sugars
Ex: glucose, fructose, galactose
Disaccharides- two monosaccharides fused together
Ex: sucrose, lactose, maltose
Polysaccharides- long chains of simple sugars chemically bonded together
Ex: starch, glycogen

16. Lipids Composed of : carbon, hydrogen, and oxygen
Fats, phospholipids, steroids

17. Fats Composed of 3 fatty acid chains and 1 glycerol 2 Types:
Saturated fat- long fatty acid chains, single bonds, solid at room temperature
Found in animal product (butter, meat)
Unsaturated fat- short fatty acid tail, double bonds, liquid at room temperature
Found in plants (cooking oils)

18. Phospholipids Composed of 2 fatty acid chains and a phosphorus group
Component of cell membranes

19. Steroids In ring structures, not fatty acid chains
They are chemicals that alter cell activity to maintain homeostasis
Ex: Cholesterol- synthesized in liver, obtained from eggs, meat, and cheese

20. Protein
Composed of carbon, hydrogen, oxygen, and nitrogen atoms (may contain sulfur & phosphorus atoms)
Amino acids- building-block molecules for protein
Peptide bond- covalent bond between 2 amino acids
Polypeptide- a chain of more than ten amino acids
Makes up to 10-30% mass of a cell

21. Nucleic Acids
Contains carbon, hydrogen, oxygen, nitrogen and phosphorus
Nucleotides- building blocks of nucleic acids
5-carbon sugar, phosphate group, nitrogenous base
Holds information of a cells structure & function

22. DNA- deoxyribonucleic acid
Nucleic acid that contains nucleotides with the five-carbon sugar deoxyribose
4 nitrogenous bases:
- adenine cytosine
- thymine guanine
Nucleotides arranged in 2 strands twisted to form a double helix
DNA contains hereditary material called genes

23. RNA – Ribonucleic Acid Contains the five carbon-sugar ribose
Nucleotides are in a single strand
Uracil instead of thymine

24. ATP- Adenosine triphosphate
Nucleotide found in all living organisms
Captures and stores energy within its bonds
Similar to RNA but with 2 additional phosphate bonds (ribose group and a adenine base group)
Cellular respiration- the break down of glucose molecules to provide energy