1. The Chemical Level of Organization
Chapter 2

2. The Chemical Level of Organization
Matter
elements
atoms and molecules
Chemical bonds
Chemical energy
Chemical reactions
Inorganic compounds
Organic compounds

3. How Matter is Organized
Chemistry is the science of the structure and interactions of matter.
all living things consist of matter.
Matter is anything that has mass and occupies space.
mass is the amount of matter in any object.
weight is the force of gravity acting on matter.
In outer space, weight is close to zero, but mass remains the same as on Earth.

4. Periodic Table of Elements

5. Main Elements in the Body

6. Structure of Atoms
Atoms are the smallest units of matter that retain the properties of an element
Atoms consist of 3 types of subatomic particles
protons, neutrons and electrons
Nucleus contains protons (p+) & neutrons (neutral charge)
Electrons (e-) surround the nucleus as a cloud.

7. Atomic Number & Mass Number
Atomic number is number of protons in the nucleus.
Mass number is the sum of its protons and neutrons.

8. Isotopes
Atoms of an element that have different numbers of neutrons (mass #’s) but the same number of protons and electrons.
Element is heavier or lighter due to more or fewer neutrons.
The properties of isotopes are similar.

9. Ions Molecules Compounds
Atoms of elements that have gained or lost one or more electrons.
1. Lose an electron - positive ion or cation (ex. Na+)
2. Gain an electron - negative ion or anion (ex. Cl-)
Molecules
Combination of two or more atoms sharing electrons.
(ex. H2O)
Compounds
Substance that contains atoms of 2 or more different elements. (ex. NaCl)

10. Holding atoms together in molecules and compounds
Chemical Bonds
Holding atoms together in molecules and compounds
Bonds within a compound:
Ionic - transfer of electrons from a cation to an anion.
Covalent - sharing of electrons between atoms.
Forces that hold molecules together:
Hydrogen bond - polar covalent bond between hydrogen and other atoms.

11. Ionic Bonds Sodium loses an electron to become Na+ (cation)
Chlorine gains an electron to become Cl- (anion)
Na+ and Cl- are attracted to each other to form the compound sodium chloride (NaCl) - table salt
Ionic compounds generally exist as solids

12. Common Ions in the Body

13. Covalent Bonds Atoms share electrons to form covalent bonds
Electrons spend most of the time between the 2 atomic nuclei
single bond = share 1 pair
double bone = share 2 pair
triple bond = share 3 pair

14. Polar Covalent Bonds Unequal sharing of electrons between atoms.
In a water molecule, oxygen attracts the hydrogen electrons more strongly
Oxygen has greater electronegativity as indicated by the negative Greek delta sign.

15. Hydrogen Bonds Only about 5% as strong as covalent bonds
Useful in establishing links between molecules
Large 3-D molecules are often held together by a large number of hydrogen bonds.

16. Chemical Reactions

17. Activation Energy
Activation energy is the energy needed to break bonds & begin a reaction.

18. Catalysts and Activation Energy

19. Water

20. Acids, Bases, and Salts

21. pH Scale pH scale runs from 0 to 14 (concentration of H+)
pH of 7 is neutral (distilled water -- concentration of OH- and H+ are equal)
pH below 7 is acidic and above 7 is alkaline
pH of 1 (10 times more H+ than pH of 2)

22. pH Scale

23. Organic Compounds Carbohydrates Lipids Proteins Nucleic Acids
Adenosine Triphosphate

24. Carbohydrates
Simple Sugars

25. Carbohydrates

26. Polysaccharide - long chains of monosaccharides.
Carbohydrates
Polysaccharide - long chains of monosaccharides.

27. Carbohydrates

28. Lipids
Saturated vs. unsaturated

29. Lipids
Triglyceride = glycerol + 3 fatty acids

30. Phospholipid
glycerol + 2 fatty acids + phosphorus group

31. Steroids

32. Types of Lipids

33. Proteins
Basic building block - amino acids

34. Functions of Proteins

35. Dipeptide - formed by combination two amino acids
Proteins
Dipeptide - formed by combination two amino acids

36. Structural Organization of Proteins

37. Proteins
Enzymes

38. Nucleic Acids Nucleotide - basic building block 1. sugar 2. phosphate
3. nitrogen base

39. Adenosine Triphosphate (ATP)