~ = ~~~~~~ ~~~~~~~~~~~~~ ~ 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 •