1. Chapter 2 The Chemical Level of Organization

3. Basic Chemistry Matter, Mass, and Weight Elements and Atoms
Matter: Anything that occupies space and has mass
Mass: The amount of matter in an object
Weight: The gravitational force acting on an object of a given mass
Elements and Atoms
Elements: The simplest type of matter with unique chemical properties
Atoms: Smallest particle of an element that has chemical characteristics of that element

4. Atomic Structure Atoms: composed of subatomic particles Nucleus
Neutrons: no electrical charge
Protons: positive charge
Electrons: negative charge
Nucleus
Formed by protons and neutrons
Most of volume of atom occupied by electrons

5. Atomic Number and Mass Number
Atomic Number: Equal to number of protons in each atom which equals the number of electrons
Mass Number: Number of protons plus number of neutrons

7. Isotopes and Atomic Mass
Isotopes: Two or more forms of same element with same number of protons and electrons but different neutron number
3 types of hydrogen
Denoted by using symbol of element preceded by mass number as 1H, 2H, 3H
Atomic Mass: Average mass of naturally occurring isotopes

8. Electrons and Chemical Bonding
Ion: When an atom loses or gains electrons and become charged
Cation: Positively charged ion
Anion: Negatively charged ion
Ionic Bonding
Cations and anions are attracted to each other

9. Covalent Bonding Atoms share one or more pairs of electrons
Single covalent: Electron pair between 2 atoms
Double covalent: Two atoms share 4 electrons
Nonpolar covalent: Electrons shared equally
Polar covalent: Electrons not shared equally

10. Electrons and Chemical Bonding
Ion: When an atom loses or gains electrons and become charged
Cation: Positively charged ion
Anion: Negatively charged ion
Formation of molecules by combination of atoms
Covalent bond:
Atoms share one or more pairs of electrons
Single covalent: Electron pair between 2 atoms
Double covalent: Two atoms share 4 electrons

11. Molecules and Compounds
Molecules: Two or more atoms chemically combine to form and independent unit
Example: Water
Compounds: A substance composed of two or more different types if atoms chemically combined
Example: Hydrogen Molecule
Molecular Mass: Determined by adding up atomic masses of its atoms or ions
Example: NaCl ( )

12. Intermolecular Forces
Result from weak electrostatic attractions between oppositely charged parts or molecules, or between ions and molecules
Weaker than forces producing chemical bonding

13. Intermolecular Forces
Hydrogen Bonds
Water: Positively charged hydrogen atoms bond with negatively charged oxygen atoms of other water molecules
Important role in determining shape of complex molecules

14. Intermolecular Forces
Solubility: Ability of one substance to dissolve in another
Example: Sugar dissolves in water
Dissociation or Separation
Ionic compounds
Cations are attracted to negative end and anions attracted to positive end of water molecules

15. Intermolecular Forces
Electrolytes: Cations (+) and anions (-) that dissociate in water
Capacity to conduct an electric current
Currents can be detected by electrodes
Nonelectrolytes: Molecules that do not dissociate form solutions that do not conduct electricity

16. Chemical Reactions
Chemical Reactions: Atoms, ions, molecules or compounds interact to form or break chemical bonds
Metabolism: All anabolic and catabolic reactions in the body
Catabolism: Decomposition reactions
Hydrolysis: Reactions that use water
Anabolism: Growth, maintenance, and repair of the body in synthesis reactions
Produce molecules characteristic of life: ATP, proteins, carbohydrates, lipids, and nucleic acids

17. Synthesis and Decomposition Reactions
Synthesis Reactions
Two or more reactants chemically combine to form a larger product
Anabolism: All body’s synthesis reactions
Decomposition Reactions
Reverse of synthesis reactions
Catabolism: Reactions of decomposition in body

18. Oxidation-Reduction Reactions
Loss of an electron by an atom
Reduction
Gain of an electron by an atom
Oxidation-Reduction Reactions
The complete or partial loss of an electron by one atom is accompanied by the gain of that electron by another atom

19. Energy Energy: The capacity to do work Potential Energy: Stored energy
Kinetic Energy: Does work and moves matter
Mechanical Energy: Energy resulting from the position or movement of objects
Chemical Energy: Form of potential energy in the chemical bonds of a substance
Heat Energy: Energy that flows between objects of different temperatures

20. Energy and Chemical Reactions

21. Speed of Chemical Reactions
Activation Energy: Minimum energy reactants must have to start a chemical reaction
Catalysts: Substances that increase the rate of chemical reactions without being permanently changed or depleted
Enzymes: Increase the rate of chemical reactions by lowering the activation energy necessary for reaction to begin

22. Activation Energy and Enzymes

23. Facts about Enzymes
Enzymes usually end in suffix -ase - and are named for the types of chemical reactions they catalyze
Oxidases add oxygen
Kinases add phosphate
Dehydrogenases remove hydrogen
ATPases split ATP
Anhydrases remove water
Proteases break down proteins
Lipases break down triglycerides.

24. The new induced fit model explains inhibitors.
There are certain false substrates that can enter an enzyme’s active site.
They bear a close resemblance in shape to the real substrates.
Because the mimicker substrate is not the real substrate, it messes up the timely workings of the enzyme. it.

25. When the mimicker substrate occupies the active site, precious reaction time is lost.
Sometimes this process is useful.
It can act in the feedback loop in order to cause a stoppage or slowing of the reaction sequence, thus controlling

26. competitive inhibitors bind to the same site as the substrate, and blocks substrate binding
A noncompetitive inhibition binds somewhere other than the active site, and blocks substrate binding

27. Enzymes are highly specific. Enzymes are very efficient.
They can speed up reactions up to 10 billion times faster.
Enzymes are under nuclear control.
Their rate of synthesis and their concentration at any given time are under the control of a cell’s genes.
Substances within a cell can either enhance or inhibit the activity of a given enzyme.
Many enzymes have active and inactive forms in cells. The rate at which the inactive form becomes active is determined by the chemical environment inside the cell.

28. Chemistry
Inorganic Chemistry: Generally deals with substances that do not contain carbon
Examples:
Water
Oxygen
Sodium
Organic Chemistry: Study of carbon-containing substances
Carbohydrate
Fat
Protein

29. Water Inorganic Stabilizes body temperature Protection
Necessary for many chemical reactions of life
Mixing Medium
Mixture: Substance physically but not chemically combined
Solution: Liquid, gas, or solid uniformly distributed
Solvent: What dissolves the solute
Solute: What is to be dissolved

30. Acids and Bases; Salts and Buffers
Acid: A proton donor or any substance that releases hydrogen ions in
Bases: A proton acceptor or any substance that binds to or accepts hydrogen ions
Salts: A cation consisting of other than a hydrogen ion and other than an anion or hydroxide ion
Buffers: A solution of a conjugate acid-base pair in which acid and base component occur in similar concentrations

31. The pH Scale Refers to the Hydrogen ion concentration in a solution
Neutral: pH of 7 or equal hydrogen and hydroxide ions
Acidic: a greater concentration of hydrogen ions
Alkaline or basic: a greater concentration of hydroxide ions

32. Organic Chemistry Carbohydrates Lipids Proteins
Composed of carbon, hydrogen, oxygen
Lipids
Composed mostly of carbon, hydrogen, oxygen
Proteins
Composed of carbon, hydrogen, oxygen,nitrogen
Nucleic Acids: DNA and RNA
Composed of carbon, hydrogen, oxygen, nitrogen, phosphorus
Adenosine Triphosphate (ATP)
Composed of adenosine and three phosphate groups

33. Carbohydrates Monosaccharides Disaccharides Polysaccharides
Simple sugars: glucose, fructose, galactose
Disaccharides
Two simple sugars bound together by dehydration: sucrose, lactose, maltose
Polysaccharides
Long chains of many monosaccharides: glycogen in animals; starch and cellulose in plants

34. Monosaccharides

35. Disaccharide and Polysaccharide

36. Lipids
Lipids: Can be dissolved in nonpolar organic solvents as alcohol or acetone but relatively insoluble in water
Fats: Ingested and broken down by hydrolysis
Triglycerides: composed of glycerol and fatty acids
Phospholipids: Important structural component of cell membranes
Eicosanoids: Derived from fatty acids
Steroids: Cholesterol, bile salts, estrogen, testosterone
Fat-soluble Vitamins

37. Phospholipids

38. Steroids

39. Proteins Amino acids: The building blocks of protein
Peptide bonds: Covalent bonds formed between amino acids during protein synthesis
Structure
Primary, secondary, tertiary, quartenary
Enzymes: Protein catalysts
Lock-and-key model
Active site
Cofactors
Coenzymes

40. Peptide Bonds

41. Protein Structure and Enzyme Action

42. Nucleic Acids: DNA and RNA
DNA: Deoxyribonucleic acid
Genetic material of cells copied from one generation to next
Composed of 2 strands of nucleotides
Each nucleotide contains one of the organic bases of adenine or guanine which are purines and thymine or cystosine which are pyrimidines
RNA: Ribonucleic acid
Similar to a single strand of DNA
Four different nucleotides make up organic bases except thymine is replaced with uracil (pyrimidine)

43. DNA Structure

44. Nucleotides and Nitrogenous Bases

45. Adenosine Triphosphate (ATP)
Energy currency of the body
Provides energy for other chemical reactions as anabolism or drive cell processes as muscle contraction
All energy-requiring chemical reactions stop when there is inadequate ATP

46. Hydrophilic and hydrophobic substances
Hydro (water), Phallic (loving)
Any ionic or polar substance that has affinity for water is said to be hydrophilic
A substance can be hydrophilic and still not dissolve in water
Cotton and paper towel will pick up water with out dissolving
This is because of the size of the molecules that made up the cotton fiber
Hydrophobic – water fearing
These are non-ionic non-polar substances that has no affinity for water; ex. – oil with non-polar molecules
Hydrophobic molecules relating to oils re major ingredient of cell membrane