~ = ~~~~~~ ~~~~~~~~~~~~~ ~ Basic Concepts m Biological Science: The Study of Life Cell Theory: Eukaryotic Cells: Z A The Scientific Method: How scientists study biology I Observe phenomena and formulate testable and fal s ifiable (in case they are wrong) hypotheses Test hypotheses, collect data, and analyze statisti­ cally (if necessary) B What is life') Characteristics: Metabolism, reproduction, growth, movement, responsiveness, complex organization All living things are composed of cell s and come from cells A Cell Size: Small to maximi ze surface area to volume ratio for regulating internal cell environment B Cell (Plasma) Membrane: Composed of fluid-like phos­ pholipid bilayer, proteins, cholesterol and glycoproteins Cell (Plasma) Membrane Evolution Concept that all organisms are rel ated to each other by common ancestry: The unifying theme in biology A Natural Selection: A mechani sm for thc occurrence of evoluti on I Survival of those offspring best adapted to the condition s in whieh they live: Individuals produce sexually many morc ofl~ spring than could poss ibly survive b These otfspring are not identical (in most situa­ tions), but show variations based on genetic dit: ferences c Essentially, those individuals with variations that allow them to survive (i.e., adaptations) to the age of reproduction can pass their genes on to the next generation d Thus, nature is selecting oflspring and shaping the evolution of species Charles Darwin and Alfred Wallace, 19th century biol­ ogists, (onnulated the concept of natural selection Organismal Evolution KI 'IG IX)"I PLANTAE FU GI " ,! "tt Phosopholipid bilaye r Cholesterol Channel protein Complex cellular organi zation A Membrane: Bound organelks induding the following: I Nucleus: DNA/chromosomes, control ce llular acti v- , ities via genes Nucleolus: Located within nucleu s sit e I,) r ribo­ some synthesis Rough endoplasmic reticulum: With ribosomes, invo lved in protein synthes is Smooth endoplasmic reticulum: With o ut ribo­ somes, involved primarily in lipid synthes is Golgi apparatus: Packaging center for molecules: carbohydrate synthesis Lysosome: Contain s hydrol ytic e nzymes 1,,,· intra­ cellular digestion Peroxisome: Invol ved in hydrogen peroxide synthe­ s is and uegradati o n Chloroplast: Site of phot osynthesi s Chromoplast: Non-green pigment s 10 Leukoplast: Stores stardl II Mitochondrion: ATP production 12 Vacuole: G eneral storage and space-fillin g structure Animal Cell C Cell Wall: Outside of cell membrane in some organisms: composed of carbohydrate (c g., cellulose or chitin) or Mi cro fil Jmenl 1\ carbohydrate derivative (c.g., peptidoglycan) D Cytoplasm: Material outside nucleus I Sitc for mctabolic activity Cytosol: Solutions with di ssolved substances slIch as' glucose, CO" 2' etc Organelles: Membrane-bound subunits of cells with specialized functions E Cytoskeleton: Supportive and metabolic structurc composed of microtubu1es, microfilaments, and inter­ mediate filaments Cytoskeleton = ~ m z ~ mot>lh endoplasmic Riho, oml!" ret iculum Plant Cell Pl a!-lma mcmhrnne Prokaryotic Cells: Simpler cellular organi zation with no nucleus or other membrane-bound organelles B Artificial Selection: Human selects traits in otf­ spring (ex: pets, farm crops) ~ Flage llum Domesticated Animals = ~ m Z Goigi apparatus Energy and Life Cell Reproduction Cell Transport Ou r Sun Passive Transport Cells reproduce in two steps: O rganisms must use the sun's energy (d irectl y o r indi­ rectly) to become and rema in in an organ ized state A Meta bolism: SC:'ies of chemica l reacti ons involved in storing (anabo lism) or re leasing (catabolism ) cnergy B Enzymes: Biologica l cata lyst: fac ilitate metabolic chem ical reactions by speeding up rates and lowering hea t req uirements En zyml' Kinetics A Relies o n thermal energy of matter; the cell docs not wo rk: th ere arc fo ur categori es : I Diffusion: Movement from an area of high to low conce ntrati o n Facilitated diffusion : A permease, or mcmbrane enzyme, carri es sub stan ce Osmosis: Diffu sion across a se mi-pe rm eabl e membrane Bulk flow: Mass movements of fluid s a tTected by pressure and solutes Osmosis A M itosis: Di vision of nuclea r materia l B Cytokin esis: Division of re maining ce llular contents of th e cytop lasm Enzyme + Substrate Enzy me/S ubstrate Enzyme + Prod uct complex /"1 HH 0-0 ~~~~tve~ ,!, ~ Prl.: SSllfC ~ -> ~ ->~ E+ S ElS com plex E+ P C Ad enos ine t ri p hospha te (AT P): A hi g h-energy mol ec ul e; energy stored in ATP is rel eased by break­ ing phosph atc-to- sph ate bonds and creat ing ad enos in e d iphos phate ( AD P) o r adenos ine ll1o no phosphak (AM P) ; AT P is recycled by adding bac k ph osphate g roups us ing energy [i'om th e sun E nergy and ATP applied to pistlJn to rL's ist upward movement Wa ter plus solute Cell Cycle A Cells go th ro ugh slag s: I G, : Acti ve growth and metabo lis m S : D NA synthes is ancl du pl ication G , : Sy lllilcs is o f mo lecules in pre paration for cell div isio n a Stages G, S, & G, above arc collec ti\ d) referred to as In terpha se: Interphase chrnmo­ so mes nrc re ferred to as chromatin , a dilrw;e loosely sca ttered arrange ment o f chro moso me, M itosis & C ytoki nesis: a Mit otic chrom osomes in the M it os i ~;lCy t o k i ­ nesis stage are hig hly co ndensed and coikd and thu s di sti nct Cell Cycle Mo lecule of so lute "-' v, • "­ «: ~ ATP l " :r: uJ • + l- · 0 •