A2 Biology Public

  • Email
  • Share
  • Contributors
  • Close Course

All you need to revise A2 Biology

Tags

Module Information

Aerobic respiration - needs oxygen and makes co2, water and 38 ATP Anaerobic respiration - absence of oxygen, produces lactate (animals) or ethanol and co2 (plants), only 2 ATP created.     Glycolysis - splitting of 6 carbon glucose into 2 x 3 carbon pyruvate Link reaction - conversion of pyruvate into co2 and 2 carbon acetylcoenzyme A Krebs cycle - introduction of acetylcoenzyme A into cycle of oxidation - reduction reactions that yield some ATP and many electrons Electron Transport Chain - use of electrons produced in Krebs cycle to synthesise ATP, h20 as by-product     GLYCOLYSIS CYTOPLASM 6 CARBON GLUCOSE CONVERTS TO 2X 3 CARBON PYRUVATE 1 - GLUCOSE PHOSPHORYLATED BY ADDITION OF TWO PHOSPHATE MOLECULES THAT COME FROM THE HYDROLYSIS OF 2 X ATP TO ADP. PROVIDES ENERGY TO ACTIVATE GLUCOSE BY LOWERING ACTIVATION ENERGY FOR ENZYME CONTROLLED REACTIONS TO FOLLOW   2 - EACH PHOSPHORYLATED GLUCOSE SPLIT INTO 2 X 3C TRIOSE PHOSPHATE   3 - TP OXIDISED, HYDROGEN REMOVED FROM EACH AND TRANSFERRED TO HYDROGEN CARRIER NAD TO FORM NADH   4 - ATP PRODUCTION - TP CONVERTED TO 3C PYRUVATE X 2.  2 X ATP REGENERATED FROM ADP.   YIELD: 2 X ATP (NET) 2 X NADH 2X PYRUVATE   LINK REACTION   PYRUVATE ACTIVELY TRANSPORTED INTO MITOCHONDRIA MATRIX. 1 - PYRUVATE OXIDISED BY REMOVING HYDROGEN. HYDROGEN ACCEPTED BY NAD TO FORM NADH   2 - 2C ACETYL GROUP FORMED FROM OXIDISED PYRUVATE COMBINES WITH COENZYME A TO PRODUCE ACETYLCOENZYME A   3 - CO2 FORMED FROM EACH PYRUVATE   KREBS CYCLE MATRIX OF MITOCHONDRIA 1 - 2C ACETYLCOENZYME A COMBINES WITH 4C MOLECULE TO GIVE 6C MOLECULE 2 - 6C MOLECULE LOSES CO2 AND HYDROGENS TO GIVE 4C MOLECULE AND SINGLE ATP DUE TO SUBSTRATE LEVEL PHOSPHORYLATION, PRODUCES NAH AND FADH 3 - 4C MOLECULE COMBINES WITH NEW ACETYLCOENZYME A TO RESTART CYCLE YIELD PER PYRUVATE - REDUCED COENZYMES: NADH, FADH, WHICH CAN PRODUCED ATP - 1 X ATP - 3 X CO2   AS 2 PYRUVATE COME FROM ONE GLUCOSE, YIELD FROM 1 X GLUCOSE DOUBLE THE QUANTITIES ABOVE.   COENZYMES - MOLECULES SOME ENZYMES REQUIRE TO FUNCTION   NAD - WORKS W/ HYDROGENASE ENZYMES THAT CATALYSE REMOVAL OF H+ AND TRANSFER THEM TO OTHER MOLECYLES SUCH AS H+ CARRIES IN OXIDATIVE PHOSPHORYLATION   IMPORTANCE OF KREBS CYCLE BREAKS DOWN MACROMOLECULES INTO SMALLER ONES. PYRUVATE BROKEN INTO CO2 PRODUCES H ATOMS, CARRIED BY NAD TO ELECTRON TRANSPORT CHAIN FOR OXIDATIVE PHOSPHORYLATION - LEADS TO PRODUCTION OF ATP REGENERATES 4C MOLECULES THAT COMBINES W/ ACETYLCOENZYME A WHICH WOULD OTHERWISE ACCUMULATE SOURCE OF INTERMEDIATE COMPOUNDS USED BY CELLS IN MANUFACTURE OF OTHER SUBSTANCES LIKE FATTY ACIDS, AMINO ACIDS AND CHLOROPHYLL     ELECTRON TRANSPORT CHAIN IN THE CRISTAE HYDROGEN ATOMS PRODUCED DURING GLYCOLYSIS AND THE KREBS CYCLE COMBINE WITH NAD AND FAD IN THE CRISTAE NADH DONATES ELECTRONS OF HYDROGEN TO FIRST ELECTRON CARRIER FADH DONATES ELECTRONS OF HYDROGEN TO SECOND ELECTRON CARRIER, MISSES THE FIRST ATP PRODUCTION PROTONS FROM HYDROGEN RELEASED ELECTRONS PASS ALONG ELECTRON CARRIER CHAIN BY OXIDATION - REDUCTION REACTIONS EACH OXIDATION REDUCTION REACTION RELEASES ENERGY, WHICH IS USED TO ACTIVELY TRANSPORT H+ ACROSS THE CRISTAE MEMBRANES INTO THE INTERMEMBRANAL SPACE CHANNEL PROTEIN THAT H+ GOES THROUGH IS A PROTON PUMP ACCUMULATION OF H+ IN THE INTERMEMBRANAL SPACE CREATES AN ELECTROCHEMICAL GRADIENT THAT THEY WOULD MOVE DOWN INTO THE INTERMEMBRANAL SPACE H+ CAN ONLY DIFFUSE THROUGH THE MEMBRANE THROUGH ATPsynthase WHICH IS ACTIVATED WHEN H+ DIFFUSES THROUGH IT, DRIVES THE REACTION OF ADP + Pi --> ATP AT THE END OF THE ELECTRON TRANSPORT CHAIN, PROTONS REASSOCIATE WITH ELECTRONS TO FORM HYDROGEN, AND ARE THEN PICKED UP BY O TO FORM H2O
Show less
ECOLOGY - STUDY OF INTERRELATIONSHIPS BETWEEN ORGANISMS AND ENVIRONMENT ABIOTIC - NON LIVING E.G TEMPERATURE BIOTIC - LIVING FACTORS E.G PREDATION BIOSPHERE - LAYER OF LAND, AIR AND WATER THAT SURROUNDS EARTH AND SUPPORTS LIFE   ECOSYSTEMS - ALL INTERACTING BIOTIC AND ABIOTIC FEATURES IN SPECIFIC AREA. SELF CONTAINED FUNCTIONAL UNITS. TWO PROCESSES: FLOW OF ENERGY THROUGH SYSTEM CYCLING OF ELEMENTS IN SYSTEM E.G NUTRIENTS, LITTLE LOSS OR GAIN BETWEEN OTHER ECOSYSTEMS E.G LAKE   POPULATIONS - GROUP OF INTERBREEDING ORGANISMS OF ONE SPECIES IN A HABITAT. BOUNDARIES DIFFICULT TO DEFINE DUE TO DISTANCE   COMMUNITY - ALL POPULATIONS OF DIFFERENT ORGANISMS LIVING AND INTERACTING IN PARTICULAR PLACE AT SAME TIME   HABITAT - PLACE WHERE A COMMUNITY OF ORGANISMS LIVE MICROHABITAT - SMALLER UNITS IN A HABITAT WITH ITS OWN MICROCLIMATE   ECOLOGICAL NICHE - WHERE AN ORGANISM LIVES AND INTERACTS, AND FITS INTO ITS ENVIRONMENT, INCLUDING ALL THE ABIOTIC AND BIOTIC FACTORS NEEDED TO SURVIVE, REPRODUCE AND MAINTAIN VIABLE POPULATION -
Show less
Abundance - number of individuals of a species in a given space   QUADRATS FACTORS TO CONSIDER SIZE OF QUADRAT TO USE NUMBER OF SAMPLE QUADRATS TO RECORD IN STUDY AREA - LARGER SAMPLE SIZE = MORE RELIABLE POSITION OF QUADRAT IN STUDY AREA - SHOULD BE RANDOM SAMPLE RANDOM SAMPLING  AVOID BIAS - ENSURE DATA VALID IF INVESTIGATING ANIMALS IN SAME TYPE OF HABITAT, CHOOSE TWO CLOSE TOGETHER TO MINIMISE ABIOTIC DIFFERENCES   LAY OUT 2 LONG TAPE MEASURES AT RIGHT ANGLES, ALONG TWO SIDES OF STUDY AREA OBTAIN SERIES OF COORDINATES, USE RANDOM NUMBERS TAKEN BY RANDOM NUMBER GENERATOR ON COMPUTER PLATE QUADRAT AT INTERSECTION OF EACH PAIR OF COORDINATES, RECORD SPECIES WITHIN IT. Point quadrat - HORIZONTAL BAR SUPPORTED BY 2 LEGS, SET INTERVALS ARE HOLES, THROUGH WHICH A PIN CAN BE DROPPED - EACH SPECIES THE PIN TOUCHES IS RECORDED Frame quadrat - SQUARE FRAME, DIVIDED INTO SMALL EQUAL SUBDIVISIONS, PLACED IN DIFFERENT LOCATIONS, ABUNDANCE OF EACH SPECIES WITHIN EACH QUADRAT RECORDED, E.G ONLY SQUARES CONTAINING OVER 50% COVERAGE COUNTED Belt transect - TWO PARALLEL STRIPS, SPECIES OCCURRING WITHIN LINES RECORDED   SYSTEMATIC SAMPLING - FOR WHEN THERE IS TRANSITION IN A COMMUNITY, SUCH AS DISTRIBUTION CHANGE AS ALTITUDE INCREASES UP A HILL. STAGES OF ZONATION ESPECIALLY WELL SHOWN USING TRANSECTS Abundance - number of individuals of a species within a given space   Limitations of frequency measurement - good if a species hard to count, but does not provide info on density and detailed distribution Percentage cover - data collected rapidly, individual plants don't need to be counted, but less useful when organisms occur in several overlapping layers    MARK, RELEASE,RECAPTURE KNOWN NUMBER OF ANIMALS CAUGHT AND MARKED IN SOME WAY, AND RELEASED. AFTER A SET TIME, A GIVEN NUMBER OF INDIVIDUALS COLLECTED RANDOMLY, MARKED INDIVUDUALS NUMBER RECORDED.   ESTIMATED POPULATION SIZE = TOTAL NUMBER OF INDIVIDUALS IN FIRST SAMPLE X TOTAL NUMBER OF INDIVIDUALS IN SECOND SAMPLE / NUMBER OF MARKED INDIVIDUALS RECAPTURED   ASSUMPTIONS: PROPORTION OF MARKED TO UNMARKED INDIVIDUALS IN SECOND SAMPLE SAME PROPORTION OF MARKED TO UNMARKED IN POPULATION AS WHOLE MARKED INDIVIDUALS RELEASED FROM FIRST SAMPLE DISTRIBUTE EVENLY AND HAVE SUFFICIENT TIME TO DO SO POPULATION HAS DEFINITE BOUNDARY SO THERE IS NO IMMIGRATION OR EMIGRATION WITHIN POPULATION FEW DEATHS OR BIRTHS METHOD OF MARKING NOT TOXIC OR MAKE THE INDIVIDUAL MORE CONSPICUOUS AND LIABLE TO PREDATION MARK NOT LOST OR RUBBED OFF DURING IVESTIGATION     CORRELATION - WHEN TWO FACTORS VARY IN RELATION TO EACH OTHER   CONSERVATION RULES DURING INVESTIGATIONS ORGANISMS STUDIED IN SITU - NOT REMOVED - OTHERWISE KEEP NUMBERS TO MINIMUM RETURN REMOVED ORGANISMS TO SITE, EVEN IF DEAD SUFFICIENT PERIOD OF TIME SHOULD ELAPSE BEFORE SITE USED FOR FUTURE STUDIES AVOID DAMAGE AND DISTURBANCE TO SITE BALANCE BETWEEN DAMAGE DONE AND VALUE OF INFO GAINED
Show less
POPULATION - GROUP OF INTERBREEDING INDIVIDUALS OF SAME SPECIES IN HABITAT - POPULATION SIZE = NUMBER OF INDIVIDUALS IN A POPULATION   GROWTH CURVES PERIOD OF SLOW GROWTH AS SMALL NUMBER OF INDIVUDALS REPRODUCE TO SLOWLY ESTABLISH NUMBERS PERIOD OF RAPID GROWTH, EVER INCREASING NUMBER OF INDIVIDUALS REPRODUCE, POP. SIZE DOUBLES DURING EACH INTERVAL OF TIME POP GROWTH DECLINES, SIZE REMAINS STABLE, CYCLIC FLUCTUATIONS DUE TO PREDATION POP SIZE AND FOOD SUPPLY, DECLINE DUE TO INCREASED PREDATIONOR LIMITING FOOD SUPPLY. CARRYING CAPACITY REACHED   WHY POPULATION GROWTH REDUCES (ALGAE) MINERAL IONS USED UP AS POPULATION GETS LARGER POPULATION SO LARGE THAT ALGAE AT SURFACE PREVENT LIGHT REACH THOSE AT DEEPER LEVELS OTHER SPECIES INTRODUCED TO POND, MAY USE ALGAE AS FOOD OR COMPETE FOR LIGHT/MINERALS WINTER BRINGS LOWER TEMPS AND LOWER LIGHT INTENSITY OF SHORTER DURATION   A SPECIES CAN ONLY LIVE WITHIN A RANGE OF ABITOIC FACTORS THAT LIMIT THEM, AND GROWTH IS LIMITED BY A LIMITING FACTOR   ABIOTIC FACTORS TEMPERATURE - EACH SPECIES HAS DIFFERENT OPTIMUM TEMP TO BEST SURVIVE. AS TEMPS FALL BELOW OPTIMUM, ENZYMES WORK MORE SLOWLY, METABOLIC RATE REDUCED. ABOVE OPTIMUM, ENZYMES WORK LESS EFFICIENTLY, UNDERGO DENATURATION   IN WARM BLOODED ANIMALS, MORE ENERGY EXPENDED TO MAINTAIN NORMAL BODY TEMP - LESS ENERGY FOR GROWTH AND REPRODUCTIVE RATE SLOW   LIGHT - ULTIMATE SOURCE OF ENERGY FOR ECOSYSTEMS (ALL INTERACTING BIOTIC/ABIOTIC FACTORS). RATE OF PHOTOSYNTHESIS INCREASES AS LIGHT INTENSITY INCREASES, MEANS MORE SPORE/ SEED PRODUCTION AND GROWTH, POP OF PREDATORS LARGER   PH - AFFECTS ENZYME ACTION IF ABOVE OR BELOW OPTIMUM   WATER AND HUMIDITY - AFFECTS TRANSPIRATION RATES AND EVAPORATION OF WATER FROM BODIES. IF WATER SCARCE LESS ORGANISMS. TOLERATION AND ADAPTATION.
Show less
WHEN RESOURCES ARE INSUFFICIENT TO SATISFY ALL INDIVIDUALS FULLY INTRASPECIFIC - SAME SPECIES  AVAILABILITY OF RESOURCES DETERMINES POPULATION SIZE. E.G LIMPETS FOR ALGAE, OAK TREES COMPETETING, LARGER ONES RETSRICT LIHT FOR SMALLER ONES WHICH DIE INTERSPECIFIC - DIFFERENT SPECIES  WHEN POPS OF TWO SPECIES OCCUPY SAME NICHE, ONE WILL HAVE COMPETITIVE ADVANTAGE COMPETITIVE EXCLUSION PRINCIPLE - COMPETITIVE ADVANTAGE SPECIES INCREASE IN SIZE WHILE OTHER SPECIES POP DIMINSIHES, IF CONDITIONS REMAIN SAME, COMPLETE REMOVAL OF ONE SPECIES COMPETITIVE EXCLUSION PRINCIPLE - WHEN 2 SPECIES ARE COMPETING FOR LIMITED RESOURCES, ONE THAT USES THESE RESOURCES MOST EFFECTIVELY WILL ULTIMATELY ELIMINATE THE OTHER. NO TWO SPECIES CAN OCCUPY SAME NICHE WHEN RESOURCES ARE LIMITING   TO SHOW HOW FACTOR INFLUENCES SIZE OF POPULATION, NECESSARY TO LINK TO BIRTH AND DEATH RATE. E.G MORE FOOD DOES NOT NECESSARILY MEAN MORE INDIVIDUALS, MIGHT JUST MEAN BIGGER ONES. HOWEVER COULD MEAN MORE LIKELY TO SURVIVE AND INCREASED PROBABILITY TO PRODUCE OFFSPRING   WHY COMPETITION MAY NOT BE FACTOR OF POPULATION MANY OTHER FACTORS E.G ABIOTIC CAUSAL LINK MUST BE ESTABLISHED TO SHOW COMPETITION CAUSE OF OBSERVED CORRELATION TIME LAG IN COMPETITION, POPULATION CHANGE MAY BE DUE TO COMPETITION FROM YEARS EARLIER DATA ON POP. SIZES HARD TO OBTAIN, NOT ALWAYS RELIABLE
Show less
EVIDENCE OF PREDATOR PREY RELATIONSHIPS IN WILD NOT RELIABLE, AS HABITAT LIMITED, AREA OF TRAVEL SMALLER, LESS REFUGE FOR PREY, ENVIRONMENT LESS DIVERSE NOT POSSIBLE TO COUNT ALL INDIVIDUALS IN NATURAL POPULATION, CAN ONLY SAMPLE AND SURVEY FOR ESTIMATIONS. EFFECT OF PREDATOR PREY RELATIONSHIP ON POP. SIZE PREDATORS EAT PREY, PREY POP REDUCES FEWER PREY = PREDATORS IN GREATER COMPETITION WITH EACH OTHER,  PREDATOR POP REDUCED, SOME UNABLE TO OBTAIN ENOUGH PREY FOR SURVIVAL FEWER PREDATORS = FEWER PREY EATEN PREY POP INCREASES MORE PREY AVAILABLE AS FOOD, PREDATOR POP INCREASES IN NATURAL ECOSYSTEMS. PRGANISMS EAT RANGE OF FOODS, FLUCTUATIONS IN POP SIZE THUS LESS SEVERE   PERIODIC POPULATION CRASHES ARE IMPORTANT IN EVOLUTION BECAUSE THEY CREATE A SELECTION PRESSURE WHEREBY ONLY THOSE BEST ADAPTED WILL SURVIVE TO REPRODUCE - POP THUS EVOLVES TO BE BETTER ADAPTED TO PREVAILING CONDITIONS
Show less
COMMUNITY - ALL POPULATIONS OF DIFFERENT ORGANISMS LIVING AND INTERACTING IN PARTICULAR PLACE AT SAME TIME SUCCESSION - CHANGES OVER TIME IN THE SPECIES THAT OCCUPY A PARTICULAR AREA   WHY BARREN LAND BECOMES COLONISED GLACIER RETREATS, DEPOSITS ROCK SAND PILED INTO DUNES BY WIND/SEA VOLCANOES ERUPT, DEPOSITS LAVA LAKES/PONDS CREATED BY SUBSIDING LAND SILT AND MUD DEPOSITED AT RIVER ESTUARIES   COLONISATION BY PIONEER SPECIES - E.G LICHEN -  Features of pioneer species tolerance to extreme conditions ability to fix nitrogen from atmosphere because soil non existent or few nurtrients ability to phoptsyntheises, not reliant on another species rapid germination of seeds, no period of dormancy production of many wind dispersed seeds/spores, can reach isolated area         2.  PIONEERS DIE, PUT ORGANIC MATERIAL IN SOI, ALLOWS RECYCLING TO START, INCREASES MINERAL IONS IN SOIL. CAN SUPPORT COMMUNITY OF SMALL PLANTS.  E.G MOSSES. ABIOTIC ENVIRONMENT CHANGED,           3. THICKER LAYER OF NUTRIENT DENSE SOIL BUILT UP. SPECIES CHANGE ABITIOIC ENVIRONMENT, MORE SUITABLE FOR ORGANISMS THAT FOLLOW, E.G GRASSES (TERTIRARY COLONISER)            4. CLIMAX COMMUNITY TREES STABLE STATE COMPRISES A BALANCED EQUILIBRIUM OF SPECIES WITH FEW IF ANY NEW SPECIES REPLACING THOSE THAT HAVE BECOME ESTABLISHED. DETERMINED BY MAIN ABIOTIC FACTOR, E.G TREES MANY BNOT GROW ON HIGH MOUNTAINS STABLE EQUILIBRIUM WITH PREVAILING CLIMATE UK = DECIDUOUS WOODLAND LESS HOSTILE, MORE NUTRIENT DENSE, HIGH SOECIES DIVERSITY AND STABILITY,  MORE NICHES AND HABITAT VARIETY LESS HARDY SPECIES CAN SURVIVE MORE COMPLEX FOOD WEBS, INCREASED BIOMASS BIODIVERSITY DECREASESA AS DOMINANT SOECIES OUTCOMPETES OTHER SPECIES   RECOLONISATION - LAND ALTERED, RETURN TO CLIMAX COMMUNITY MORE QUICKLY DUE TO SPORES/SEEDS IN SOUIL, INFLUX OF ANIMALS THROUGH DISPERSAL/MIGRRATION
Show less
Management of Eearth's natural resources in such a way that max. use of them can be made in the future, involves active intervention by humans ti maintain ecosystems and biodiversity   Ethical reasons species occupied earth longer than us, should be allowed to coexist respect for living things better than disregard for them Economic living organisms contain gigantic pool of genes with capacity to make millions of substances, which may prove valuable in future long term productivity greater if ecosystems maintained at natural balanced state Cultural and aesthetic enrich our lives inspire adds interest to life Manage succession to prevent a climax community. Burn healther and sheep grzing
Show less
OCCURS IN CYTOPLASM INVOLVES GLYCOLYSIS AND JUST ONE OTHER STEP 2 ATP PRODUCED PER GLUCOSE MOLECULE, COMPARED TO 38 AEROBICALLY KREBS AND ELECTRON TRANSPORT CHAIN DON'T TAKE PLACE FOR GLYCOLYSIS TO CONTINUE, PYRUVATE AND HYDROGEN MUST BE CONSTANTLY REMOVED H MUST BE RELEASED FROM NADH IN ORDER TO REGENERATE NAD, OTHERWISE NAD WILL BE ENTIRELY CONVERTED TO NADH, LEAVING NO NAD TO TAKE UP H NEWLY PRODUCED FROM GLYCOLYSIS, WHICH WILL THUS HALT   REPLENISHMENT OF NAD ACHIEVED BY PYRUVATE MOLECULE FROM GLYCOLYSIS ACCEPTING H FROM NADH   PLANTS GLUCOSE ---> CO2 + ETHANOL + 2ATP PYRUVATE AT END OF GLYCOLYSIS LOSES CO2 TO PRODUCE ETHANAL BY DECARBOXYLATION. ETHANAL ACCEPTS HYDROGEN FROM NADH TO PRODUCE ETHANOL BY REDUCTION pYRUVATE + NADH ---> NAD + CO2 + ETHANOL   ANIMALS PYRUVATE + NADH ---> LACTATE + NAD H TAKEN UP BY NAD BECOMES NADH, USED TO REDUCE PYRUVATE INTO LACTATE. NAD REGENERATED TO NADH BY ACCEPTING THE 2H FROM GLUCOSE OXIDATION OF TP INTO PYRUVATE RELASES ATP (FOR PLANTS TOO)
Show less