Science

1. Science Chemistry

2. What is Chemistry? • The science dealing with the structure and composition of substances, the changes in composition, and the mechanisms by which the changes occur. • The study of matter and its interactions.

3. What is matter? • Anything that occupies space and has mass. • Everything!

4. Changes in composition • What changes matter? • Nature • External force • Most changes in matter accompany energy. • What does chemistry and these changes in composition have to do with respiratory therapy?

5. Definitions • Atom • The smallest unit of an element that can exist either alone or in combination with atoms of the same or different elements. Consist of protons, neutrons, and electrons. • Element • A substance that cannot be further decomposed by ordinary chemical means, a substance in which all the atoms have the same number of protons.

6. Definitions Cont. • Molecule • The smallest chemical unit of a substance that is capable of stable existence. • Molecules are made up of one or more atoms. If they contain more than one atom, the atoms can be the same (an oxygen molecule has two oxygen atoms) or different (a water molecule has two hydrogen atoms and one oxygen atom). Biological molecules, such as proteins and DNA, can be made up of many thousands of atoms.

7. Definitions Cont. • Compound • A chemical compound is a chemical substance formed from two or more elements, with a fixed ratio determining the composition. For example, dihydrogen monoxide (water) is a compound composed of two hydrogen atoms for every oxygen atom.

8. The Atom

9. The Atom • Nucleus • Protons • Neutrons • Electrons • What is a neutral atom?

10. Periodic table • Symbols • Atomic numbers (# of protons) • Mass numbers (protons & neutrons) • Rows (Periods) • Columns (Groups or Families)

11. Periodic table • Metals • Alkali Metal Elements • Alkali Earth Elements • Nonmetals • Halogen Elements • Noble Gas Elements • Metalloids • Transition Metal Elements • Main Group Elements

13. Electrons • Excited state • Ground state • Energy levels

15. Electron Configuration • Quantum Atomic Model • Bohr Model • Lewis Electron Dot Model

16. Electrons and Energy levels • How many are there? • How many electrons can they hold? • How do the electrons fill the levels? • Shell (energy levels 1-7) • Sub-shell (s,p,d,f) • Orbital

17. Quantum Atomic Model

18. Quantum Atomic Model

19. Bohr Model

20. Lewis Electron Dot Model

21. Valence Electrons • Combining capacity. • Number given to an atom that indicates it’s tendency to loose or gain electrons in a chemical reaction. • How many electrons are in an atom’s outer shell to be considered full?

22. Periodic table short cuts • Periods = # of shells each elements has • Groups = # of electrons in outer shell (valence electrons)

24. Stable atoms • Atoms are said to be stable when their outer most shell is full. • Which elements are stable on the periodic chart? • Elements who do not have 8 electrons in their outer shell are constantly looking for a way to be stable.

25. How do atoms fill their outer levels? • Take electron(s) from another atom. • Give electron(s) to another atom. • Share electron(s) with another atom.

26. Ions • When atoms give or take electrons it changes their neutrality. • Ion = an atom that has an electrical charge as a result of gaining or losing electrons. • Cation = positively charges ion • Anion = negatively charged ion.

27. Types of bonds • Ionic = a bond that has formed as a result of the atoms in the compound gaining/losing electrons. • Covalent = a bond that has formed by the sharing of electrons between the various atoms in the compound. • Hydrogen (Polar covalent) = occur when a Hydrogen atom is covalently bonded to a Nitrogen or Oxygen atom and is attracted to another Nitrogen or Oxygen atom.

28. Isotopes • Atoms of an element having the same chemical properties but different atomic weights. • So if all atoms of a certain element have the same number of protons, what changes the atomic weight?

29. Radioactive Isotopes • Used in nuclear medicine • Very unstable • We manipulate their nuclear structure. • They emit high energy radiation. • They can be detected by instruments to evaluate the function of body parts. • They do damage cells.

30. Balancing Equations • The substances that are starting material in a chemical reaction are REACTANTS. • The substances produced as a result of the reaction are called PRODUCTS. • Balancing a chemical equation consist of make your REACTANTS and Products equal.

31. Balancing Equations • Is this balanced? • H + Cl² → HCl • NO WAY! • What would a balanced equation look like • 2H + Cl² → 2HCl

32. Balancing Equations • Difference between a subscript and a coefficient. • Subscript (N²) Can NEVER be changed! • Coefficient (2N) Can always be changed! • Coefficients need to be REDUCED aka SMALL!

33. Organic & Inorganic Compounds • Organic compounds are molecules that contain carbon to carbon bonds and/or carbon to hydrogen bonds. • Inorganic compounds do not contain carbon. Inorganic compounds come principally from mineral sources of non-biological origin. Inorganic compounds often includes all metal-containing compounds, even those found in living systems.

34. Inorganic Compounds • Types of inorganic compounds • Major branches of inorganic compound groups include: • Minerals, such as salt, asbestos, silicates, ... • Metals and their alloys, like iron, copper, aluminum, brass, bronze, ... • Compounds involving non-metallic elements, like silicon, phosphorus, chlorine, oxygen, for example water • Metal complexes

35. Inorganic Compounds • What do you think is the most abundant inorganic substance in the human body?

36. Wonderful Water! • Absorbs and releases heat very slowly • Requires a large amount of heat to change from a liquid to a gas. • Serves as lubricant • It participates in chemical reactions • Hydrolysis • Dehydration synthesis • Is a great solvent!

37. Solution • A solution (salt water) is composed of a solvent (water) and a solute (salt).

38. Organic Compounds • Always contain carbon to carbon and/or carbon to hydrogen bonds. • Most organic compounds are bound by covalent bonds containing hydrogen.

39. 4 major organic compounds found in the body • Carbohydrates • Lipids • Proteins • Nucleic Acids

40. Carbohydrates • Carbohydrates are the bodies most readily available source of energy. • The building blocks are monosaccharides. • Carbohydrates are divided into 3 main groups based on size. • Monosaccharides • Disaccharides • Polysaccharides

41. Lipids • Lipids protect and insulate the body. • Lipids are an inefficient source of energy. • Fats are lipids that are solid @ room temperature, and oils are lipids that are liquid @ room temperature. • The building blocks are triglycerides, which are made up by one glycerol to three fatty acids.

42. Lipids cont. • There are three types of lipids found in the body. • Triglycerides • Saturated fat • Monounsaturated • Polyunsaturated • Phospholipids • Steroids • Cholesterol

43. Proteins • Proteins have structural and functional properties in the body.

44. Proteins cont. • Structural • Help form structures (e.g. collagen) • Hold body tissues together • Form a fibrous water-proof layer on skin (keratin) • Functional • Participate in chemical processes such as hormones, growth factors & cell membranes. • Help reactions occur BUT are not reactants • They are chemical catalyst called ENZYMES, which speed up reactions. • Each enzyme has a shape that “fits” into the molecules involved in a reaction with the “Lock and Key Method”.

45. Proteins cont. • The building blocks are amino acids. • When two or more amino acids combine the are bonded by peptide bonds.

46. Nucleic Acids • Nucleic acids are extremely large organic molecules containing carbon, hydrogen, oxygen, nitrogen, and phosphorus. • The building blocks are nucleotides. • There are two principle kinds: • DNA (deoxyribonucleic acid) • RNA (ribonucleic acid)

47. DNA (deoxyribonucleic acid) • Double helix • The uprights of the ladder consist of alternating phosphate groups and the deoxyribose portions (sugar) of the nucleotides. • The rungs on the ladder consist of alternating paired nitrogenous bases. • Adenine paired with Thymine • Cytosine paired with Guanine • About 1000 rungs of DNA nucleotides comprise a gene.

48. RNA (ribonucleic acid) • Single strand • RNA’s sugar ribose does not contain oxygen. • RNA does not contain the nitrogenous base thymine, instead it contains Uracil. • RNA has a specific role to perform with DNA in protein synthesis.

49. Acids, Bases, and Salts…Oh my • Acids, bases, and salts are considered inorganic compounds.

50. Acids, Bases, and Salts…Oh my • Acid • typically water-soluble, when the acid disassociates (is dissolved) in water it produces an excess of hydrogen ions (H+) • sour-tasting chemical compound • In common usage an acid is any substance that, when dissolved in water, gives a solution a pH of less than 7. • An acid reacts with a base in a neutralization reaction to form a salt.