Biology

1. Biology living/once- living things “the study of” What determines if something is living?

2. There is no single definition of life. However, there is a list of characteristics by which we determine if something is living or not. In order to be considered “living”, you need to display the potential for all of the following life functions: 1. Nutrition- obtaining materials from the environment and processing them for use within the organism. • a. heterotrophs- organisms that consume food (dog, human) ingestion- taking in food digestion- breaking down food egestion- removal of undigested or indigestible food ex) corn, fiber, throwing up

3. What must an oak tree do to stay alive that both a fly and a human must also do?

4. b. Autotrophs- “auto”= self “trophic”= nutrition (plants) chlorophyll light enzymes *Photosynthesis: CO2 + H2O C6H12O6 + O2 + H2O

5. 2. Transport- the absorption and circulation of materials within an organism • a. single-celled organisms (or any cell w/in an • organism… • materials are diffused/absorbed • directly across the cell membrane • b. multi-celled organisms- • most cells aren’t in • contact w/the environment so a circulatory • system is needed • 3. Respiration- The exchange of O2 and CO2AND the release of energy that is stored in food molecules.(glucose) • a. anaerobic- • does not use oxygen, produces little • energy • b. aerobic- • does use oxygen, produces lots of • energy, more efficient • C6H12O6 + O2 CO2 + H2O + Energy(36 ATP) • (glucose)

6. 4. Excretion- the removal of wastes from cells + from an organism which were produced during life processes. • lungs remove CO2 + H2O • skin removes H2O, salts + urea • kidneys remove H2O, salts + urea • liver removes dead RBCs • 5. Synthesis & Assimilation- The incorporation of these synthesized molecules into the organism’s body Ex) when proteins become part of a body builder’s muscles from a protein-rich diet chemical reactions where large molecules are built from smaller ones “You are what you eat!!!”

8. 6. Regulation- the control & coordination of all life activities in an effort to maintain homeostasis (stable internal enviroment) • 2 systems involved: • a. nervous- • electrical: brain, spinal cord, nerves • b. endocrine- • chemical: hormones, glands • 7. Growth- increase in size and/or number of cells • you grow in # of cells from infant teen • an ameba’s 1 cell can increase in size • requires materials that were synthesized • from the nutrients ingested

9. 8. Reproduction- creating a new organism/cell ~species survival is dependent on reproduction, individual survival is not. ~asexual & sexual • 2 parents, • offspring have a combination of parents’ traits • 1 parent, • identical offspring, • no variety

10. Metabolism the total of all life processes/chemical reactions working together to keep an organism alive

11. Homeostasis The maintenance of a stable internal environment w/in an organism • ex) maintaining a constant body temperature, blood • sugar level

12. Borderline cases of living things: Seeds, flower bulbs, viruses, HIV • They display only some of the life functions some of the time. At other times, they are said to be dormant (“sleeping”) More on viruses…….. • contain genetic material but lack other cell • structures to carry out metabolism • they are not cells and do not fit into any kingdom • they cannot reproduce without a host cell …….disruption of homeostasis!! http://phschool.com/ Enter code cbp-6192 End of notes for Life Function Quiz

13. How did we discover the cell?

15. The Cell • `the basic unit of all living things Historical Background (don’t need to put in notes) • A. 1600s • Robert Hooke- coined the word “cell” when • looking at cork w/a compound microscope • (he was seeing their cell walls) • Anton Von Leeuenhoek- used a simple • microscope (1 lens). He was the 1st to see • living cells (blood, pond water organisms)

16. 1800s • Dutrochet- (1824) stated that all living things are • made of cells • 2. Brown- (1831) 1st to see a nucleus • 3. Schleiden (1838)- said that all plants are made of cells • Schwann (1839)- said that all animals are made of • cells • Virchow (1855)- said that all cells arise from other • cells

17. These discoveries led to the development of the Cell Theory • 1. All living things are made of 1 or more cells. • Cells are the basic unit of structure and function • (can carry out life processes). • 3. New cells arise from other cells. • Exceptions to the Cell Theory • ~where did the 1st cell come from? • ~viruses: not made of cells, no DNA, can only • reproduce w/host cell • Laser clip “Intro to Cell Study”

18. Microscopes 1. Simple- • 1 lens • magnifies 3-10 times • AKA magnifying glass 2. Compound- (what we use at school) • 2 lenses • magnifies 40-400 times • See diagram

19. Practice w/this diagram: ocular/eyepiece body tube nosepiece arm objective lens objective lens objective lens stage stage clips coarse adjustment diaphragm fine adjustment light base

20. 3. dissecting/stereo microscope- • 2 eyepieces: binocular • magnifies 6-60 times • shows external features (ex. fly, ladybug) • creates a 3-D image • 4. Electron- • developed in 1930s • bounces electrons off of specimen (instead of light) • creates a 3-D image • magnifies more than 250,000 times • views specimens in a vacuum (kills live specimens)

21. Tips for microscope use: • Start on low power • Brighter • Larger field of view • To get total magnification: • multiply the power of the eyepiece by objective lens • When you switch from low to high: • center your specimen, b/c you will only see a • fraction of the center of the specimen when you go • to high power • the field of view gets smaller and darker • only use fine adjustment on high power • objects appear upside down and backwards in the • field • under the scope • becomes

22. when you move the slide to the left, the image moves • to the right & vice-versa • Preparing a wet mount slide: • add a drop of water to a slide • add specimen (cheek cell, onion cell, etc.) • put coverslip on at a 45o angle (removes air bubbles) • Staining a specimen: • Place 1 drop of stain at the edge of the coverslip • Place a paper towel at the opposite edge so that the • water from under the coverslip is absorbed and stain • is drawn under coverslip paper towel stain

23. How do you measure organisms under the microscope??? You can use ruler under low power:

25. Microscopic Measurement: • in a meter, there are 1000mm (millimeters) • Units: • in 1 mm., there are 1000 um (micrometers/microns) • Determine the approximate • diameter of the cell in um. • The cell takes up approx • one quarter of the field • 1.6 / 4 = .4 mm. • = 400um • 1.6 mm. • (diameter of the field of view)

27. Chromatography- • “chrom” = color • process in which a substance (ink, chlorophyll) is separated into its component parts/colors • By comparing the separation color bands of the unknown substances to that of a known substance, an identification may be made.

28. Misc Lab Tips…. • Always wear goggles when using chemicals. • When heating a material in a test tube: • point tube away from you • never put a stopper in the tube • glassware: test tube beaker Graduated cylinder- always read volume at meniscus flasks

29. Science uses the metric system: • grams • liters • meters • with prefixes such as • milli- • centi- • kilo- • Conducting an Experiment: • A valid experiment must have the following elements: • A question you are trying to answer or problem • you want to investigate • A control- • the setup that remains the same through the experiment; provides a comparison

30. A variable- • the element/factor that changes in the experiment (amount of sun, water) • -a valid experiment tests only ONE variable at a time • independent- • variable that does not depend on a factor in the experiment (ex. time, days) • dependent- • relies on the independent variable • ex) plant growth depends on time, time does not depend on plant growth • A hypothesis- • possible answer to the question you are asking • often posed as an “if…then…” statement

31. An observation- • what you see happening; provides data for analysis • Data- • must be measureable (height, length, number) • A conclusion- • Sums up the findings. Scientists use the data to determine whether the hypothesis was supported or refuted • Refers to the # of organisms being tested. The larger the sample size, the more valid the results are. • Sample size- • # of trials- • the more trials you do, the more valid your experiment is

32. The Cell

33. Smallest unit of living things • Present in all living things • Have many tiny “organs” called organelles • These organelles carry out life functions • Cells can be organized into more complex levels: • organelle • cell • tissue • organ • organ system • organism Cell size & scale illustration

34. Cells are specialized to perform different functions • ex)nerve cells carry electrical messages • muscle cells move body parts • gland cells produce hormones • Cells are most often microscopic (10- 100 um) • exceptions: • chicken egg- 6 cm. • nerve cell- up to 1 meter!

35. Cell Organelles • small structures inside cell • suspended in cytoplasm (the watery material • inside the cell where chemical reactions occur) • carry out life functions • 1. Cell (plasma) membrane- • Surrounds and protects the cell • is selectively permeable • (regulates the passage of • materials into and out of the cell) and therefore • maintains homeostasis (tries to) *Life function: Transport, Regulation, Excretion • Recognizes chemical signals from outside the membrane or from other cells using:

36. receptors- structures on the membrane that receive outside “messages” (have specific shapes and will only allow things inside the cell that fit their shape!) receptors “message” cell

37. Video clip: membrane Receptors:

38. Virus receptor clip, http://phschool.com use code cbp 6192

39. 2. nucleus- control center for the cell (brain) • contains: • chromosomes- • (DNA in rod-like, coiled form) *Life function: regulation, reproduction, metabolism, etc

40. 3. ribosomes- • synthesize proteins • may be free in cytoplasm or lining E.R. *Life function: synthesis • 4. Endoplasmic Reticulum- (“ER”) • a network of fluid filled channels connected to the nuclear membrane • transport materials w/in cell • smooth ER- not lined w/ ribosomes • rough ER- lined w/ribosomes *Life function: transport, synthesis

41. 5. lysosomes- “stomach” of the cell • small sacs that contain digestive chemicals *Life function: nutrition

42. 6. vacuole- • membrane enclosed sacs ~food: contain food & fuse w/vesicle ~ contractile: in freshwater protists, pumps out excess water • plant vacuoles are much larger than animal *Life function: nutrition, excretion, homeostasis (powerhouse) • 7. mitochondria- • site of cellular respiration; releases energy (ATP)

43. *Life function: respiration

44. 8. chloroplasts- found in plant cells only • contain chlorophyll • site of photosynthesis *Life function: synthesis, nutrition

45. 12. Cell wall- • non-living • surrounds & supports plant cells • composed of cellulose (complex carbohydrate) • 13. Cilia & flagella- • hair-like structures that help an organism move • cilia • flagella

46. *reminder……… • A cell can be part of a multicellular organisn (dog, tree) OR • A cell can be an entire organism (ameba, paramecium) HOW?! • the organelles present in a single celled organism act like the systems (resp., excretory, etc) in a multicellular organism • these organisms perform all of the life functions needed to stay alive

47. *reminder……… plant cells animal cells Large vacuoles Chloroplasts Cell membrane & cell wall Small vacuoles No chloroplasts Cell membrane only “cyto” = prefix meaning cell Laser clip: cell *review life funct