Basic Chemistry

1. Basic Chemistry

2. Matter and Energy • Matter – anything that occupies space and has mass (weight) • Energy – the ability to do work • Chemical • Electrical • Mechanical • Radiant

3. Composition of Matter • Elements • Fundamental units of matter • 96% of the body is made from four elements • Carbon (C) • Oxygen (O) • Hydrogen (H) • Nitrogen (N) • Atoms = Building blocks of elements

4. Components of the AtomAtoms are made up of 3 basic particles Protons – positive charg Neutrons – negative charge Electrons – negative charge Protons & Neutrons join together to form the nucleus

5. Atomic Structure • Nucleus • Protons (p+) • Neutrons (n0) • Outside nucleus • Electrons (e-) Figure 2.1

8. Identifying Elements • Atomic number • Equal to the number of protons that the atoms contain • Atomic mass number • Sum of the protons and neutrons • Atomic weight • basically the mass number of all isotopes of an element. • Isotopes and Atomic Weight

9. Isotopes and Atomic Weight • Isotopes • Have the same number of protons • Vary in number of neutrons Figure 2.3

10. Radioactivity • Radioisotope • Heavy isotope • Tends to be unstable • Radioactivity = process of spontaneous atomic decay

11. Molecules and Compounds • Molecule – two or more like atoms combined chemically • Compound – two or more different atoms combined chemically • Atoms are united by chemical bonds • Atoms dissociate from other atoms when chemical bonds are broken • Chemical bonds: ionic, covalent, hydrogen bonds

13. Straight chain of glucose molecules, some are branched,

14. Chemical Bonds – Ionic Bonds • Ionic Bonds – gain or loose electrons • Form when electrons are transferred from one atom to another • Ions • Charged particles • Anions - negative • Cations - positive • Either donate or accept electrons

15. ionic bond  A chemical bond in which atoms of opposite charge are held together by electrostatic attraction.

16. Chemical Bonds – Covalent Bond • Covalent Bonds – share electrons • Atoms become stable through shared electrons • Single covalent bonds share one electron • Double covalent bonds share two electrons Figure 2.6c

17. Polarity • Covalent bonded molecules • Some are non-polar • Electrically neutral molecule • Some are polar • Have a positive and negative side Figure 2.7

18. Chemical Bonds – Hydrogen Bond • Hydrogen bonds • Weak chemical bonds • Hydrogen is attracted to negative portion of polar molecule • Provides attraction between molecules

19. Patterns of Chemical Reactions • Synthesis reaction (A+BAB) • Atoms or molecules combine, build up • Energy is absorbed for bond formation • Decomposition reaction (ABA+B) • Molecule is broken down (by a catalyst) • Chemical energy is released

20. Synthesis and Decomposition Reactions Figure 2.9a–b

21. Biochemistry: Essentials for Life Organic compounds Contain carbon Most are covalently bonded Example: C6H12O6 (glucose) Water, salts, acids-bases Inorganic compounds Lack carbon Tend to be simpler compounds Example: H2O (water) Carbohydrates, proteins, fats, sugars & starches

22. Important Inorganic Compounds • Water • Most abundant inorganic compounds • Vital properties • High heat capacity – prevents sudden changes in body temperature. • Polarity/solvent properties – dissolve or suspend. Nutrients, resp. gases, waste, carbon dioxide. • Chemical reactivity – uses water as a reactant, (hydrolysis), to digest foods. • Cushioning – cerebrospinal fluid, amniotic fluid.

23. Water and Living Things Characteristics of water polarity: • Liquid – remains liquid in our bodies. • Universal solvent – facilitate chemical reactions in/out of our bodies • Cohesive properties – helps water base- solutions fill blood vessels Without hydrogen bonding between water molecules, body fluids would be a gaseous form

24. Water and Living Things Characteristics of water polarity • Ability to change temperatureslowly – prevents drastic changes • Vaporization – keeping body temperature from overheating • Ability to freeze – becomes less dense and in weight.

25. Important Inorganic Compounds • Salts • Easily dissociate into ions in the presence of water • Vital to many body functions • Include electrolytes which conduct electrical currents ( Na, K, Cl, Ca, Phos.) in the body

26. Important Inorganic Compounds • Acids & Bases = another form of electrolytes; they are ionize and dissociate in water causing electrical conduction. • Acids - release Hydrogen ions. Sour or sharp taste, tomato juice, coffee, vinegar • Bases - Proton acceptors – gain Hydrogen ions Bitter taste, become slippery when wet,MOM, ammonia, household cleaners & detergents • Neutralization reaction • Acids and bases react to form water and a salt

27. pH • Measures relative concentration of hydrogen ions • pH 7.0 = neutral • pH below 7.0 = acidic • pH above 7.0 = basic • Buffers: chemicals that regulate pH change • pH needs to be maintain in humans in order to maintain homeostasis

28. Organic Molecules & Compounds

29. Important Organic Compounds • Carbohydrates • Contain carbon, hydrogen, and oxygen • Include sugars and starches • Classified according to size • Monosaccharides – simple sugars • Disaccharides – two simple sugars joined by dehydration synthesis • Polysaccharides – long branching chains of linked simple sugars

30. Carbohydrates Monomer Polymers

31. Important Organic Compounds • Lipids • Contain carbon, hydrogen, and oxygen • Carbon and hydrogen outnumber oxygen • Insoluble in water • Neutral fats (triglycerides) • Found in fat deposits, solid, animal fat • Composed of fatty acids and glycerol • Source of stored energy • Saturated vs. Unsaturated fats

32. Lipids - Emulsification • Emulsifiers • Fats are nonpolar; they do not dissolve in water and tend to form “globules” (oil and vinegar dressing) • Emulsifier breaks down the globules of fat into smaller droplets • detergens, bile

33. Lipids – other forms • Common lipids in the human body • Phospholipids • Form cell membranes – cell wall, electrical charge which allows selective permeability of the cell wall. • Steroids • Include cholesterol, bile salts, vitamin D, and some hormones (corticosteriods, sexual hormones

34. Important Organic Compounds • Proteins • Made of amino acids • Contain carbon, oxygen, hydrogen, nitrogen, and sometimes sulfur • Meats, meat products, milks, beans, nuts. • Fibrous proteins – collegen, keratin • Globular proteins – gentic material, DNA

35. Proteins • Account for over half of the body’s organic matter • Provides for construction materials for body tissues • Plays a vital role in cell function • Act as enzymes, hormones, and antibodies • Proteins molecules can easily denatured (deformed) by heat and enzyme reactions.

36. Enzymes • Act as biological catalysts • Increase the rate of chemical reactions Figure 2.17

37. Important Organic Compounds • Nucleic Acids • Provide blueprint of life that make DNA and RNA • Nucleotide bases • A = Adenine • G = Guanine • C = Cytosine • T = Thymine • U = Uracil

38. Nucleic Acids • Deoxyribonucleic acid (DNA) • Organized by complimentary bases to form double helix • Replicates before cell division • Provides instruction for every protein in the body Figure 2.18c

39. Important Organic Compounds • Adenosine triphosphate (ATP) • Chemical energy used by all cells • Energy is released by breaking high energy phosphate bond • ATP is replenished by oxidation of food fuels