1. Safety review

2. CHAPTER 1 THE SCIENCE OF LIFE

3. Lets play a game…  Am I alive?  How can you tell?

13. Characteristics of Life?  Organization  Response to stimuli  Homeostasis  metabolism  Growth and Development  Reproduction  Change through time

14. Organization  High degree of order between internal and external parts  Interactions with the living world  Examples?

15. Response to stimuli  Ability to respond to changing environment

16. Homeostasis  ability to maintain a stable internal condition.  No matter the changes in environment.

17. Metabolism  Use of energy to power life processes

18. Growth and Development  Growth?  increase in amount of living material  Development?  process ending in adulhood  Ie. Frog

19. Reproduction  Production of Offspring  Coded information is passed on to the offspring  Like Produces Like

20. Change through time  evolution

21. Science as a process  Scientific method  Organized approach to learn how the natural world works

22. Scientific method 1. Observation / question: 2. Hypothesis: tries to answer question; proposed explanation 3. Prediction: guesses what will happen 4. Experiment: tests hypothesis 5. Collect and analyze data 6. Supports or disputes hypothesis

23. Scientific theory  When a set of confirmed hypotheses is confirmed to be true many times  Examples?

24. Tools of the trade  Microscopes 1. Compound light microscope  Uses light through a specimen  Electron microscpes use a stream of electrons to visualize a specimen 2. Scanning (SEM) electron microscope  3-D surface view 3. Transmission (TEM) electron microscope  2-D internal view

25. Compound Light Microscope

26. Scanning Electron Microscope SEM

27. Transmission Electron Microscope TEM

29. Light vs. Electron

30. SEM or TEM SEM TEM TEMSEM

31. SEM or TEM SEM TEM TEM SEM

32. More SEM

37. The Metric System Common Metric Units Length (meters)Mass (grams) 1 meter (m) = 100 centimeters (cm) 1 meter = 1000 millimeters (mm) 1000 meters = 1 kilometer 1 kilogram (kg) = 1000 grams (g) 1 gram = 1000 milligram (mg) 1000 kilograms = 1 metric ton (t) Volume (liters)Temperature (Celcius) 1 liter (L) = 1000 milliliters (mL) 1 liter = 1000 cubic centimeters (cm 3 ) 0 o Celsius (C) = freezing point of water 100 o C = boiling point of water System of measuremnt in science. Based on multiples of ten = easy conversion

38. Ch 1 Vocab quiz next class 1. Biology 2. Compound light microscope 3. Electron microscope 4. Gene 5. Hypothesis 1. Metabolism 2. Metric system 3. Organization 4. Scientific method 5. Theory

39. CH 2 CHEMISTRY OF LIFE

40. Matter  Everything is made of matter (?)  Has mass and occupies space

41. Elements and atoms  Element: substances that cannot be broken down into simpler substances  Atoms: smallest particle of an element that retains the properties of that element

42. Atomic structure  Nucleus makes up most of mass of an atom  Consists of protons (positive) and neutrons (no charge)  Number of protons = atomic number  Number of protons + neutrons = mass number

43. Atomic structure  Electrons: negatively charged particles  Balance out with positive charge of protons  Very small mass  Move around the nucleus in orbitals

44. Isotopes  Atoms of same element have equal number of protons but not necessarily neutrons  Isotopes: atoms of the same element that have a different number of neutrons

45. Compounds  Made of atoms of two or more elements  H 2 O  CO 2  CH 4

46. A Covalent Bond occurs when atoms share electrons Covalent Bonds

47. Ionic Bonds Example: Sodium Chloride Oppositely charged atoms, attracted to each other Note: they do not share electrons

48. Energy and Matter  Energy: ability to do work  Many types of energy  Electrical  Radiant (light)  Thermal (heat)  Chemical  mechanical

49. Chemical reactions  One or more substances change to produce one or more different substances  Reactants: on the left side of the equation

50. Chemical reactions  One or more substances change to produce one or more different substances  Products: on the right side of equation

51. Activation energy  Energy needed to start a reaction  Catalysts reduce activation energy  Example: enzymes

53. Water and solutions  Properties of water are necessary for life  Many of water’s functions come from it’s chemical structure  Polarity: uneven distribution of charges  Water is polar  Polar nature allows water to dissolve polar substances

55. Hydrogen bonding  Polar nature allows water to be attracted to one another  + region of one moleculue attracted to the – region on another

56. Cohesion and adhesion  Cohesion: attractive force between molecules of a single substance  Water attracted to water  Adhesion: attractive force between molecules of different substances  Water attracted to other stuff

57. Quick cohesion and adhesion lab  HOW MANY DROPS OF WATER CAN I PUT ON LINCOLN’S HEAD?  Get in lab groups.  Send one member up to the front to get a penny and a cup  Count the number of drops that you can put on the head of a penny

58. Temperature moderation  Water has a high heat capacity  Water can absorb or release large amounts of energy with only a slight change in temperature  This allows water to absorb heat during the summer to keep air cool w/o increasing the temp.  And at night, water cools and warms the air

59. Density  Is ice more or less dense than water?  Discuss with your partner and write your ideas down in your notes

60. Solutions  Solution: mixture of two or more substances  Solute: substance that dissolves in a solvent  Solvent: substance in which the solute is dissolved

61. Acids and bases  pH scale is used to measure acidity or alkalinity  Scale from 0  14  0  6.9: acid  7 neutral (water)  7.1  14: base  Buffers: chemical substances that neutralize small amounts of acids or base added to a solution  They keep the pH from changing greatly