(IP) sec 2: science notes 2021

Titleofcontents:)) HumanDigestiveSystem HumanSexualReproductiveSystem ChemicalBonding ChemicalChanges Forces EnergyWorkPower Electricity InteractionswithinEcosystems HumanDigestiveSystem -consistsofthealimentarycanalandtheassociatedorgans-alimentarycanalconsistofthemouth,oesophagus,stomach,smallintestine,largeintestine,rectumandtheanus(basicallyroutewherefoodpassesthrough)-associatedorgansincludesalivaryglands,pancreas,gallbladderandliver Functionsofthedifferentpartsofthedigestivesystem-Digestionoffoodbeginsinthemouth,andcontinuesinthestomachandendsinthesmallintestine

-Physicaldigestion(e.g.chewingandchurningactionofthestomach)helpstobreakfoodintosmallerpieces-Chemicaldigestionbyenzymeshydrolysesthefoodmoleculesintosimpler,moresolubleanddiffusiblemoleculessothattheycanbeabsorbedintothebloodstream Enzymes-substancesproducedbythebodythatspeedsuptherateofchemicalreactions,includingdigestion,biologicalcatalyst-ORWELLSbiologicalcatalyststhataltertherateofchemicalreactionsinourbodywithoutbeingchangedandarespecificinaction classofenzymes actson end(final)productsofdigestion carbohydrate(e.g.amylaseandmaltase) carbohydrates Simplesugars(e.g.glucose) protease proteins aminoacids lipase fats fattyacidsandglycerol structure functions mouth physicalandchemicaldigestionoccurshere!1. teethbreakfoodintosmallerpieces-increasesurfaceareatovolumeratioofthefoodwhichallowsittobedigestedfaster-easiertoswallow2. salivaryglandssecretesalivawhichcontainssalivaryamylase-amylaseisanenzymethatdigestsstarchtomaltose3. noproteinsorfatsdigestioninthemouth salivaryglands -produceandsecretesalivacontainingsalivaryamylase esophagus -amusculartubethatcontractsandrelaxesrhythmicallytopushthefooddownintothestomach stomach -stomachchurnstobreakfoodupandmixesitwithgastricjuice-gastricjuicecontainshydrochloricacidandprotease-hydrochloricacidkillsbacteria-proteasedigestsproteinsintosimplerproteins(polypeptides)-NOcarbohydrateorfatsdigestion pancreas 1. producespancreaticjuice-containsamylase,proteaseandlipaseforthedigestionofscratch,proteinsandfatsrespectively gallbladder -releasesbileintothesmallintestine-bileisproducedintheliverbutstoredinthegallbladder-bilebreaksupfatsintotinyfatdroplets-thisincreasesthesurfaceareatovolumeratiooffatsfordigestionbylipasetospeedupdigestion smallintestine -partiallydigestedfood(acidchyme)enteringfromthestomachmixedwithdigestivejuicesfromthepancreas,gallbladderandintestinalglands-foodiscompletelydigestedinsmallintestine

largeintestine -onlyfoodthatcannotbedigestedentersthelargeintestine-thecolonabsorbsremainingwateranddissolvedions-therectumstoresfecestemporarily anus -feces(containingundigestedfood)isexpelledfromthebodythroughtheanus Endproducts-arerelativelysmall-smallenoughtopassthroughwallsofsmallintestineandintothebloodvessels,tobedistributedtotheotherpartsofthebodybythecirculatorysystem-mostofthewaterconsumedisalsoabsorbedinthesmallintestine-theremainingwateranddissolvedionsareabsorbedinthecolon endproductofdigestion howtheyareusedbythebody gluc