1. Resource: 2004. Johnson, George B. and Peter H. Raven. Biology. Holt, Rhinehart, and Winston. Unit 1 Principles of Cell Biology

2. Chapter 1: Biology and You • Chapter 2: Chemistry of Life • Chapter 3: Cell Structure • Chapter 4: Cells and Their Environment • Chapter 5: Photosynthesis and Cellular Respiration

3. Chapter 1 Biology and You

4. Section 1 Themes of Biology

5. Introduction • Organisms: - living things • Biology: - is the study of life

6. Characteristics of Living Organisms • All living things share seven characteristics: • composed of one or more cells • is able to reproduce • obtains and uses energy (to run the processes of life) • maintains a constant internal environment

7. 5. passes on traits to offspring 6. responds and adjusts to the environment 7. grows and develops • Life: - is a defined by the presence of all of the characteristics of living organisms at some stage in an organism’s life. • Science: • from Latin for “to know, is a systematic process of inquiry

8. Unifying Themes of Biology • Theme 1: Cellular Structure and Function • Theme 2: Reproduction • Theme 3: Metabolism • Theme 4: Homeostasis • Theme 5: Heredity • Theme 6: Evolution • Theme 7: Interdependence

9. Theme 1: Cellular Structure and Function • Cells: • are highly organized, tiny structures with thin coverings called membranes. • Smallest unit capable of all life functions. • The basic structure of cells is the same in all organisms, although some cells are more complex than others

10. Theme 2: Reproduction • Reproduction: • the process by which organisms make more of their own kind from one generation to the next • Metabolism: • is the sum of all the chemical reactions carried out in an organism Theme 3: Metabolism

11. Theme 4: Homeostasis • Homeostasis: • the maintenance of stable internal conditions in spite of changes in the external environment

12. Theme 5: Heredity • Gene: • basic unit of heredity • are coded in a molecule called deoxyribonucleic acid (DNA) and determine an organism’s traits • Heredity: - is the passing of traits from parent to offspring

13. Mutations: • a change in the DNA of a gene • majority are harmful though a few are helpful • when occur in sex cells they are passed on to other generations • when occur in body cells they are not passed on (but may result in cancers)

14. Theme 6: Evolution • Evolution: • change in the inherited characteristics of species over generations • Species: • is a group of genetically similar organism that can produce fertile offspring • Natural Selection: • the process in which organisms with favorable traits are more likely to survive and reproduce

15. Theme 7: Interdependence • Biological Community: - is a group of interacting organism • Ecology: • the study of the interactions of organisms with one another and with the nonliving part of their environment • Interdependence: • the idea that all organisms are dependent on one another and their environment

16. Section 2 Biology in Your World

17. Solving Real-World Problems

18. Preserving Our Environment • Conservation: • planned management of natural resources • Preservation: • to maintain

19. Improving the Food Supply • Genetic Engineering: • involves the transfer of genes from one organism to another, which changes the heredity information in its cells

20. Understanding the Human Genome • Genome: • the complete genetic material contained in an individual • in April of 2003 the mapping of the human genome was complete

21. Fighting Disease

22. AIDS • HIV: • causes AIDS • a virus that attacks and destroys the human immune system

23. Cancer • Cancer: • is a growth defect in cells, a breakdown of the mechanism that controls cell division

24. Emerging Disease • West Nile: • a virus that is transmitted by mosquitoes and can infect other animas such as humans, birds etc • Mad Cow: • a fatal disease of cattle caused by eating the body parts of infected animals • can infect humans when they eat meat or other products of infected cattle

25. Gene Therapy • Cystic Fibrosis: • caused by an inherited defect in a gene • a fatal disorder in which a thick sticky mucus clogs passages in many of the body’s organs • Gene Therapy: • the replacement of a defective gene with a normal version

26. Section 3 The Scientific Processes

27. The Scientific Processes • Observation • Stages of Scientific Investigation • Scientific Explanations

28. Solving Scientific Puzzles • Observation: • The basis of scientific research • the act of noting or perceiving objects or events using the senses • is the first step in a scientific investigation a.k.a. scientific method

29. Stages of Scientific Investigation • There are generally six steps/stages in a scientific investigation • collecting observations • asking questions • forming hypotheses • making predictions (with controlled experiments) • drawing conclusions • Repeat

30. Collecting Observations • The key to a scientific investigation is careful observation

31. Asking Questions • Questions arise from observations

32. Forming Hypotheses and Making Predictions • Hypothesis: • an explanation that might be true • must be testable through observations or experimentation • Prediction: • the expected outcome of a test, assuming the hypothesis is correct

33. Confirming Predictions • pH: • a relative measure of the hydrogen ion (H+) concentration within a solution • Experiment: • a planned procedure to test a hypothesis • Controlled Experiment: • an experiment in which an experimental group is compared with a control group

34. Experimental Group: • group that receives some type of experimental treatment • Control Group: • group in an experiment that receives no experimental treatment • The control and experimental groups are designed to be identical except for on factor or variable

35. Independent variable: • the factor that is changed in an experiment • Dependent variable: • the variable that is measured in an experiment

36. Drawing Conclusions • Does the result of the experiment support the hypothesis?

37. Viewing Conclusions in Context

38. Repetition and Further Evidence Gathered

39. Scientific Explanations • Model: • a representation of an object or system • often used to mean a hypothetical description • Theory: • a set of related hypotheses that have been tested and confirmed many times by many scientists • unites and explains a broad range of observations

40. Constructing a Theory • Constructing a theory often involves considering contrasting and conflicting hypotheses • Scientists evaluate each other’s work • Scientific research must be able to be replicated – reproduced by other scientists

41. There is no absolute certainty in a scientific theory – the possibility always remains that future evidence will cause a scientific theory to be revised or rejected • See Flow Chart

42. Chapter 2 Chemistry of Life

43. Looking Ahead • Section 1: Nature of Matter • Section 2: Water and Solutions • Section 3: Chemistry of Cells • Section 4: Energy and Chemical Reactions

44. Section 1 Nature of Matter

45. Atoms • Atoms – • all matter consists of atoms • are the smallest unit of matter that cannot be broken down by chemical means • consists of two parts: the nucleus and the electrons • In a neutral atom (no electrical charge) there is one electron for every proton

46. Nucleus – • located at the center of the atoms • is made up of positive protons and neutral atoms • has an overall positive electrical charge • Electrons – • located outside of the nucleus • have a negative electrical charge

47. Elements • Elements – • a pure substance made of only one kind of atom • are identified by the number of protons they have • Isotopes – • atoms of an element that contain different numbers of neutrons

48. Chemical Bonding • Chemical Bond – • force that holds two atoms together • Compound – • a substance made of the joined atoms of two or more different elements • Chemical Formula – • represents a compound • identifies the elements in the compound and its proportions

49. Covalent Bonds • Covalent Bond - • Bond that forms when electrons are shared • Molecule – • Is a group of atoms held together by covalent bonds

50. The arrangement of their electrons determines how atoms bond together • Electrons are grouped into levels • The further the level is from the nucleus of an atom the more energy the electrons contain • Each level can only hold a limited amount of electrons