Biology living/once- living things What determines if something is living? the study of 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- digestion- egestion- taking in food breaking down food removal of undigested or indigestible food ex) corn, fiber, throwing up What must an oak tree do to stay alive that both a fly and a human must also do? b. Autotrophs- *Photosynthesis: auto= self trophic= nutrition (plants) chlorophyll light enzymes CO 2 + H 2 O C 6 H 12 O 6 + O 2 + H 2 O 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 arent in contact w/the environment so a circulatory system is needed a. anaerobic- 3. Respiration-The exchange of O 2 and CO 2 AND the release of energy that is stored in food molecules.(glucose) does not use oxygen, produces little energy b. aerobic- does use oxygen, produces lots of energy, more efficient C 6 H 12 O 6 + O 2 CO 2 + H 2 O + Energy (36 ATP) (glucose) 4. Excretion- The incorporation of these synthesized molecules into the organisms body Ex) when proteins become part of a body builders muscles from a protein- rich diet skin removes H 2 O, salts + urea lungs remove CO 2 + H 2 O kidneys remove H 2 O, salts + urea liver removes dead RBCs 5. Synthesis & Assimilation- chemical reactions where large molecules are built from smaller ones the removal of wastes from cells + from an organism which were produced during life processes. You are what you eat!!! 6. Regulation-the control & coordination of all life activities in an effort to maintain homeostasis (stable internal enviroment) a. nervous- b. endocrine- 2 systems involved: electrical: brain, spinal cord, nerves chemical: hormones, glands 7. Growth-increase in size and/or number of cells you grow in # of cells from infant teen an amebas 1 cell can increase in size requires materials that were synthesized from the nutrients ingested 8. Reproduction-creating a new organism/cell ~species survival is dependent on reproduction, individual survival is not. 2 parents, offspring have a combination of parents traits 1 parent, identical offspring, no variety ~asexual & sexual Metabolism the total of all life processes/chemical reactions working together to keep an organism alive Homeostasis The maintenance of a stable internal environment w/in an organism ex) maintaining a constant body temperature, blood sugar level 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!!Enter code cbp-6192 End of notes for Life Function Quiz How did we discover the cell? The Cell `the basic unit of all living things Historical Background (dont need to put in notes) 2.Anton Von Leeuenhoek- used a simple microscope (1 lens). He was the 1 st to see living cells (blood, pond water organisms) 1.Robert Hooke- coined the word cell when looking at cork w/a compound microscope (he was seeing their cell walls) A. 1600s 3. Schleiden (1838)- said that all plants are made of cells 2. Brown- (1831) 1 st to see a nucleus B.1800s 1.Dutrochet- (1824) stated that all living things are made of cells 4.Schwann (1839)- said that all animals are made of cells 4.Virchow (1855)- said that all cells arise from other cells 3. New cells arise from other cells. 2. Cells are the basic unit of structure and function (can carry out life processes). 1. All living things are made of 1 or more cells. Laser clip Intro to Cell StudyIntro to Cell Study ~where did the 1 st cell come from? Exceptions to the Cell Theory ~viruses: not made of cells, no DNA, can only reproduce w/host cell These discoveries led to the development of the Cell Theory 1 lens Microscopes magnifies times 2 lenses AKA magnifying glass magnifies 3-10 times 1. Simple- 2. Compound- (what we use at school) See diagram body tube nosepiece objective lens stage clips diaphragm light ocular/eyepiece arm stage coarse adjustment fine adjustment base Practice w/this diagram: 3. dissecting/stereo microscope- 4. Electron- 2 eyepieces: binocular magnifies 6-60 times shows external features (ex. fly, ladybug) creates a 3-D image developed in 1930s bounces electrons off of specimen (instead of light) views specimens in a vacuum (kills live specimens) magnifies more than 250,000 times creates a 3-D image Tips for microscope use: Start on low power Brighter Larger field of view 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 becomes under the scope To get total magnification: multiply the power of the eyepiece by objective lens 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 45 o angle (removes air bubbles) 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 Staining a specimen: paper towel stain How do you measure organisms under the microscope??? You can use ruler under low power: Microscopic Measurement: in a meter, there are 1000mm (millimeters) in 1 mm., there are 1000 um (micrometers/microns) Determine the approximate diameter of the cell in um. 1.6 mm. ( diameter of the field of view) The cell takes up approx one quarter of the field 1.6 / 4 =.4 mm. = 400um Units: 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. When heating a material in a test tube: Always wear goggles when using chemicals. never put a stopper in the tube point tube away from you glassware: Misc Lab Tips. beaker test tube flasks Graduated cylinder- always read volume at meniscus 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 A variable-the element/factor that changes in the experiment (amount of sun, water) -a valid experiment tests only ONE variable at a time variable that does not depend on a factor in the experiment (ex. time, days) relies on the independent variable ex) plant growth depends on time, time does not depend on plant growth independent- dependent- A hypothesis- possible answer to the question you are asking often posed as an ifthen statement Data- what you see happening; provides data for analysis A conclusion-Sums up the findings. Scientists use the data to determine whether the hypothesis was supported or refuted Sample size- Refers to the # of organisms being tested. The larger the sample size, the more valid the results are. An observation- must be measureable (height, length, number) # of trials- the more trials you do, the more valid your experiment is The Cell organelle 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: cell tissue organ organ system organism Smallest unit of living things Cell size & scale illustration 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 ( um) exceptions: chicken egg- 6 cm. nerve cell- up to 1 meter! 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) Recognizes chemical signals from outside the membrane or from other cells using: *Life function: Transport, Regulation, Excretion receptors- structures on the membrane that receive outside messages (have specific shapes and will only allow things inside the cell that fit their shape!) cell receptors message Receptors : Video clip: membrane Virus receptor clip,use code cbp 6192 control center for the cell (brain) contains: 2. nucleus- chromosomes-(DNA in rod-like, coiled form) *Life function: regulation, reproduction, metabolism, etc synthesize proteins may be free in cytoplasm or lining E.R. a network of fluid filled channels connected to the nuclear membrane transport materials w/in cell *Life function: synthesis 3. ribosomes- 4. Endoplasmic Reticulum- (ER) smooth ER- not lined w/ ribosomes rough ER- lined w/ribosomes *Life function: transport, synthesis 5. lysosomes- stomach of the cell small sacs that contain digestive chemicals *Life function: nutrition 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 site of cellular respiration; releases energy (ATP) (powerhouse) *Life function: nutrition, excretion, homeostasis 7. mitochondria- *Life function: respiration 8. chloroplasts-found in plant cells only contain chlorophyll site of photosynthesis *Life function: synthesis, nutrition 12. Cell wall- non-living composed of cellulose (complex carbohydrate) surrounds & supports plant cells 13. Cilia & flagella- hair-like structures that help an organism move cilia flagella *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 cyto = Large vacuoles Chloroplasts Cell membrane & cell wall Small vacuoles No chloroplasts Cell membrane only *reminder prefix meaning cell Laser clip: cell *review life functreview life funct plant cells animal cells