What is Biology?

1. What is Biology?

2. Biology Book reference pages16-22 • Definition: • “bio-” = • “-logy” = • This includes the structure, function, growth, origin, evolution and distribution (where they live and how they get around) of living organisms.

3. Anything that is or once was alive is…. LIVING!!!

4. 5 Characteristics of Life • Organization • Specialized for a purpose • Ex. Cells, tissues, organs, organ systems • The cell is the smallest unit capable of life function

5. 5 Characteristics of Life • Reproduction • Asexually vs. Sexually • Within a species

6. 5 Characteristics of Life • Energy • Light, nutrients • ATP – adenosine triphosphate: a molecule in muscle tissue that is the major source of energy for cellular reactions

7. 5 Characteristics of Life • Growth & Development • Change in size • Change in shape/form

8. 5 Characteristics of Life • Response and Adaptation • Response to an environmental stimulus • Adaptation is change in a population of same organisms in response to changes in the environment

9. Origin of Life - 2 Theories • Spontaneous Generation • Life from non-life (since at least 4 BC) • FranscescoRedi’s experiment (1668) • Louis Pasteur experiment (1864) • Biogenesis • “bio-” = • “-genesis” = • Life comes from life • Reproduction occurs within the same species

10. Redi’s Experiment

12. Origin of Life - 2 Theories • Spontaneous Generation • Life from non-life (since at least 4 BC) • Franscesco Redi’s experiment (1668) • Louis Pasteur experiment (1864) • Biogenesis • “bio-” = • “-genesis” = • Life comes from life • Reproduction occurs within the same species

13. P H E O C Problem Hypothesis Experiment Safety Materials Procedure Data Observation Conclusion

14. Problem & Hypothesis Observation: I have a headache. P: How do I get rid of my head ache? H: If I… Observation: My car won’t start. P: Why won’t my car start? H: Observation: Plants seem to grow towards the window. P: Do plants grow towards artificial light? H:

15. Terms Variable = factor that changes in an experiment You should only test ONE variable in an experiment!! Why? Experimental Group = factor being tested Control Group = “normal” condition or condition that you are comparing against Constants = conditions that remain the same between experimental group and control group Independent Variable = It’s the variable “I control” Dependent Variable = effect caused by changes in the independent variable, what you observe

16. Example Problem: How does excess fertilizer affect the growth of of a houseplant Hypothesis: If excess fertilizer is added then the plant will grow taller Variable = Experimental Group = Control Group = Constants = Independent Variable = Dependent Variable =

17. Data

19. 10 Levels of Organization • Cell • Basic unit of living things • Tissue • Made up of cells working together for the same function • Organ • Made up of tissues working together for the same function

20. 10 Levels of Organization • Organ System • Made up of organs working together for the same function • Organism • All living things • Population • A group of organisms of the same species • Ex. Turtles in a pond

21. 10 Levels of Organization • Community • All populations living/working together • Biotic • Ecosystem • Living and non-living parts of a community • Biotic and abiotic

22. 10 Levels of Organization • Biome • A large group of similar ecosystems, determined by climate • Biosphere • Thin layer of air, land and water that is home to living things

23. Chemistry of Life • Atom = smallest particle of an element • proton • neutron • electron • isotope • form of the element with different amount of neutrons; usually unstable and radioactive

24. Chemistry of Life • atomic mass: • average mass of an atom of an element - sum of protons and neutrons in nucleus • atomic number: • proton number • symbol: • one or two letters used internationally

25. Chemistry of Life • Periodic Table

26. Model of an Atom

27. Chemistry of Life • Bohr Model vs. Electron Cloud Model

28. Chemistry of Life • Bonding = energy is exchanged when bonds break/form • ex. Na+ Cl- NaCl • ex. H2O • Molecule – two or more atoms • Compound – molecule of two or more elements

29. Properties of H2O • Cohesion • Adhesion • Surface tension • Capillary action

30. Chemistry of Life Water strider

31. Chemistry of Life Green Basilisk Lizard

32. Organic Compounds • Organic compounds contain carbon • Ex. Carbon skeleton • Monomer • “one” unit • Dimer • “two” units • Polymer • “many” units

33. 4 Compounds Found in Living Things • Carbohydrates • Protein • Lipid • Nucleic Acid

34. 4 Compounds Found in Living Things • Carbohydrates • Starch (Iodine Test) • Sugar (Benedict’s Test) • Cellulose • Protein • Nitric Acid Test • Lipid • Smear test • Nucleic Acid

35. Carbohydrates • Starch (Iodine Test) • Long lasting energy • ex. Potato, pasta • Sugar (Benedict’s Test) • Short term energy • ex. Candy, glucose • Cellulose • Gives structure • Found in plants

36. Protein (Nitric Acid Test) • Polymers of amino acids (20) • Provide structure (muscles, skin) • ex. Eggs, meat

37. Lipids (Smear Test) • Fat • Insulation • Long lasting energy • Waxes • Waterproofing • Water storage • Steroids • Growth & development • Phospholipid • Cell membrane

38. Nucleic Acid • DNA • Genetic code • RNA • Makes proteins

39. Chemical Reaction • Process that changes one set of chemicals into another set of chemicals • Ex. CO2 + H2O  H2CO3 H2O2  H2O + O2

40. Energy • Bonds broken/formed • Activation Energy • Energy to get a reaction started • Energy absorbed (endergonic) vs. Energy released (exergonic)

41. Endergonic reaction requires energy to start reaction and absorbs the energy If you touched a beaker in which an endergonic reaction was occurring, what would you feel?

42. Exergonicreaction needs a small amount of energy to start but releases energy as part of the reaction If you touched a beaker in which an endergonic reaction was occurring, what would you feel?

43. Endergonic reaction requires energy to start reaction and absorbs the energy Exergonic reaction needs a small amount of energy to start but releases energy as part of the reaction

44. Enzymes • Proteins that act as catalysts • Catalyst = speeds up the rate of a chemical reaction • Lower activation energy

45. Enzyme lowers the activation energy: EA = activation energy

46. Enzymes • Enzymes provide a site where reactants can be brought together to react • Substrate = the reactants of enzyme-catalyzed reactions

47. Enzymes • Lock-and-Key Fit • Active Site

48. Enzymes • Enzyme is not used up in reaction, can start again after product is released • Things That Affect Enzymes • pH (how acid or basic the environment is) • Temperature (hot vs. cold) • What is the optimal condition for enzymes in the human body?

49. Review • What are the 4 compounds that make up living things? • What do they all have in common? • What are the three types of carbohydrates? • How are they related? • What is a protein made up of? • How do the 20 amino acids compare to the 26 letters in the alphabet? • How are lipids beneficial?

50. Review • Where are lipids found in living things? • What are nucleic acids? • What role do they play in living things? • What foods contain carbohydrates? • What foods contain lipids? • What foods contain proteins? • Where are proteins found in our bodies?