Cells - Biology PDF

‭Cells‬ ‭ ells‬‭are‬‭the‬‭building‬‭blocks‬‭of‬‭life.‬‭Most‬‭cells‬‭have‬‭similar‬‭parts.‬‭Each‬‭living‬‭cell‬‭contains‬ C ‭protoplasm‬‭.‬ ‭Protoplasm‬ ‭This‬‭is‬‭made‬‭up‬‭of‬‭three‬‭parts:‬‭the‬‭cell‬‭surface‬‭membrane,‬‭the‬‭cytoplasm,‬‭and‬‭the‬‭nucleus.‬ ‭Below‬‭are‬‭the‬‭protoplasm‬‭parts‬...

‭Cells‬ ‭ ells‬‭are‬‭the‬‭building‬‭blocks‬‭of‬‭life.‬‭Most‬‭cells‬‭have‬‭similar‬‭parts.‬‭Each‬‭living‬‭cell‬‭contains‬ C ‭protoplasm‬‭.‬ ‭Protoplasm‬ ‭This‬‭is‬‭made‬‭up‬‭of‬‭three‬‭parts:‬‭the‬‭cell‬‭surface‬‭membrane,‬‭the‬‭cytoplasm,‬‭and‬‭the‬‭nucleus.‬ ‭Below‬‭are‬‭the‬‭protoplasm‬‭parts‬‭of‬‭cells.‬‭If‬‭it’s‬‭limited‬‭to‬‭plants‬‭or‬‭animals‬‭only,‬‭it‬‭will‬‭be‬‭stated.‬ ‭❡‬‭Cell‬‭surface‬‭membrane‬ ‭❡‬‭Cytoplasm‬‭(Will‬‭be‬‭further‬‭defined)‬ ‭❡‬‭Nucleus‬‭(Will‬‭also‬‭be‬‭further‬‭defined,‬‭calm‬‭down)‬ ‭❡‬‭Cell‬‭Wall‬‭(Plant‬‭only)‬ ‭ he‬‭Cell‬‭surface‬‭membrane‬‭is‬‭a‬‭selectively‬‭permeable‬‭membrane‬‭which‬‭controls‬‭substances‬ T ‭moving‬‭in‬‭and‬‭out‬‭of‬‭the‬‭cell‬‭and‬‭acts‬‭as‬‭receptor‬‭sites‬‭for‬‭recognising‬‭external‬‭stimuli‬‭and‬ ‭chemicals.‬‭It‬‭allows‬‭smaller‬‭substances‬‭such‬‭as‬‭water‬‭to‬‭pass‬‭through.‬‭It‬‭is‬‭made‬‭of‬‭proteins‬ ‭and‬‭phospholipids.‬‭It‬‭forms‬‭a‬‭boundary‬‭between‬‭the‬‭contents‬‭of‬‭the‬‭cell‬‭and‬‭the‬‭external‬ ‭environment.‬ ‭The‬‭cytoplasm‬‭is‬‭an‬‭aqueous‬‭ground‬‭substance‬‭containing‬‭organelles‬‭such‬‭as‬‭the‬‭nucleus.‬ ‭ he‬‭nucleus‬‭contains‬‭hereditary‬‭material‬‭and‬‭DNA‬‭in‬‭the‬‭form‬‭of‬‭chromatin‬‭threads‬‭which‬ T ‭condense‬‭into‬‭highly-coiled‬‭chromosomes‬‭visible‬‭under‬‭the‬‭light‬‭microscope‬‭during‬‭cell‬‭division.‬ ‭The‬‭nuclear‬‭membrane‬‭surrounds‬‭the‬‭nucleoplasm.‬‭The‬‭nuclear‬‭membrane‬‭consists‬‭of‬‭two‬ ‭membranes,‬‭one‬‭is‬‭continuous‬‭with‬‭the‬‭endoplasmic‬‭reticulum.‬‭The‬‭nuclear‬‭membrane‬‭is‬ ‭perforated‬‭with‬‭pores‬‭which‬‭control‬‭the‬‭substances‬‭moving‬‭in‬‭and‬‭out‬‭of‬‭it.‬‭The‬‭nucleus‬‭also‬ ‭controls‬‭and‬‭directs‬‭activities‬‭of‬‭the‬‭cell,‬‭such‬‭as‬‭cell‬‭growth.‬ ‭ he‬‭cell‬‭wall‬‭is‬‭an‬‭inflexible,‬‭inelastic,‬‭and‬‭totally‬‭permeable,‬‭and‬‭is‬‭made‬‭up‬‭of‬‭cellulose.‬‭It‬ T ‭may‬‭undergo‬‭extensive‬‭lignification.‬‭The‬‭cell‬‭was‬‭protects‬‭the‬‭cell‬‭from‬‭overextension‬‭and‬ ‭provides‬‭support‬‭for‬‭the‬‭cell.‬ ‭Cytoplasm‬‭and‬‭organelles‬ ‭ he‬‭cytoplasm‬‭contains‬‭the‬‭organelles‬‭of‬‭the‬‭cell.‬‭Each‬‭organelle‬‭is‬‭specialised‬‭for‬‭a‬‭particular‬ T ‭function.‬ ‭Below‬‭are‬‭the‬‭organelles‬‭of‬‭a‬‭cell.‬ ‭❡‬‭Rough‬‭endoplasmic‬‭reticulum‬ ‭❡‬‭Smooth‬‭endoplasmic‬‭reticulum‬ ‭❡‬‭Golgi‬‭apparatus‬‭(and‬‭vesicles)‬ ‭❡‬‭Ribosomes‬ ‭❡‬‭Mitochondria‬ ‭❡‬‭Chloroplasts‬‭(Plant‬‭only)‬ ‭❡‬‭Vacuole(s)‬ ‭ ndoplasmic‬‭reticulum‬‭(in‬‭general)‬‭-‬‭Network‬‭of‬‭folded‬‭membranes‬‭forming‬‭sheets,‬‭tubes,‬‭or‬ E ‭flattened‬‭sacs‬‭called‬‭cisternae‬‭in‬‭cytoplasm,‬‭originating‬‭from‬‭the‬‭outer‬‭membrane‬‭of‬‭the‬ ‭nuclear‬‭membrane.‬ ‭ he‬‭rough‬‭endoplasmic‬‭reticulum‬‭is‬‭covered‬‭with‬‭ribosomes‬‭on‬‭the‬‭outer‬‭surface‬‭of‬‭the‬ T ‭membrane.‬‭It‬‭transports‬‭proteins‬‭manufactured‬‭by‬‭the‬‭ribosomes‬‭which‬‭are‬‭then‬‭exported‬‭out‬‭of‬ ‭the‬‭cell.‬ ‭ he‬‭smooth‬‭endoplasmic‬‭reticulum‬‭is‬‭not‬‭covered‬‭in‬‭ribosomes‬‭and‬‭is‬‭more‬‭tubular.‬‭It‬ T ‭synthesises‬‭hormones‬‭and‬‭steroids‬‭,‬‭detoxifies‬‭harmful‬‭substances‬‭into‬‭harmless‬‭materials,‬‭and‬ ‭gives‬‭rise‬‭to‬‭the‬‭Golgi‬‭body.‬ ‭ he‬‭golgi‬‭apparatus/body‬‭is‬‭a‬‭compact‬‭stack‬‭of‬‭membrane-bound‬‭sacs‬‭and‬‭golgi‬‭vesicles.‬ T ‭Sacs‬‭are‬‭fluid‬‭filled‬‭and‬‭pinch‬‭at‬‭the‬‭ends‬‭to‬‭form‬‭golgi‬‭vesicles.‬‭It‬‭has‬‭a‬‭convex‬‭face‬‭where‬ ‭vesicles‬‭from‬‭ER‬‭fuse‬‭with‬‭the‬‭golgi‬‭body,‬‭and‬‭a‬‭concave‬‭face‬‭where‬‭vesicles‬‭pinch‬‭off.‬‭It‬ ‭chemically‬‭modifies‬‭substances‬‭manufactured‬‭by‬‭the‬‭ER,‬‭and‬‭stores‬‭and‬‭packages‬‭them‬‭for‬ ‭secretion‬‭out‬‭of‬‭the‬‭cell.‬ ‭ he‬‭ribosomes‬‭are‬‭made‬‭of‬‭ribosomal‬‭RNA‬‭and‬‭proteins‬‭and‬‭can‬‭be‬‭found‬‭in‬‭the‬‭cytoplasm‬‭or‬ T ‭attached‬‭to‬‭endoplasmic‬‭reticulum.‬‭RER‬‭ribosomes‬‭synthesise‬‭secretory‬‭proteins,‬‭while‬‭free‬ ‭ribosomes‬‭synthesize‬‭intra-cellular‬‭proteins.‬ ‭ he‬‭mitochondria‬‭is‬‭a‬‭double‬‭membrane‬‭organelle‬‭that‬‭is‬‭rod-shaped,‬‭releases‬‭energy‬‭in‬‭the‬ T ‭form‬‭of‬‭ATP‬‭(Adenosine‬‭Triphosphate).‬‭(Highly‬‭active‬‭cells‬‭may‬‭possess‬‭up‬‭to‬‭1000.)‬ ‭ he‬‭chloroplasts‬‭has‬‭a‬‭double‬‭membrane.‬‭Chloroplasts‬‭contain‬‭a‬‭series‬‭of‬‭membranes‬ T ‭(thylakoids)‬‭running‬‭through‬‭a‬‭matrix‬‭where‬‭chlorophyll‬‭can‬‭be‬‭located.‬‭Thylakoids‬‭can‬‭be‬ ‭stacked‬‭to‬‭form‬‭a‬‭granum.‬‭Contains‬‭starch‬‭grains‬‭converted‬‭from‬‭glucose‬‭from‬‭photosynthesis.‬ ‭Chloroplasts‬‭contain‬‭chlorophyll‬‭pigment‬‭to‬‭absorb‬‭sunlight‬‭to‬‭manufacture‬‭glucose‬‭during‬ ‭photosynthesis.‬ ‭ he‬‭vacuole‬‭is‬‭a‬‭fluid-filled‬‭organelle‬‭surrounded‬‭by‬‭a‬‭selectively‬‭permeable‬‭vacuolar‬ T ‭membrane.‬‭It‬‭provides‬‭support‬‭for‬‭a‬‭plant‬‭by‬‭being‬‭filled‬‭with‬‭water,‬‭and‬‭temporarily‬‭stores‬ ‭waste‬‭products‬‭and‬‭food‬‭reserves.‬ ‭Cell‬‭specialisation‬ ‭ here‬‭are‬‭many‬‭different‬‭types‬‭of‬‭cells‬‭in‬‭the‬‭human‬‭body.‬‭Differentiation‬‭is‬‭the‬‭process‬‭of‬ T ‭newly‬‭produced‬‭cells‬‭developing‬‭special‬‭structures‬‭or‬‭losing‬‭certain‬‭structures‬‭to‬‭carry‬‭out‬ ‭specific‬‭functions.‬ ‭ ell‬‭specialisation‬‭allows‬‭cells‬‭to‬‭be‬‭more‬‭efficient‬‭at‬‭its‬‭tasks.‬‭However,‬‭if‬‭an‬‭unusual‬‭need‬ C ‭arises,‬‭it‬‭will‬‭be‬‭less‬‭able‬‭to‬‭adapt‬‭to‬‭that.‬ ‭ ‬‭tissue‬‭is‬‭a‬‭group‬‭of‬‭cells‬‭with‬‭similar‬‭structures‬‭which‬‭work‬‭together‬‭to‬‭perform‬‭a‬‭specific‬ A ‭function.‬‭Simple‬‭tissue‬‭are‬‭cells‬‭of‬‭the‬‭same‬‭kind‬‭which‬‭group‬‭together.‬‭Muscular‬‭tissue‬‭is‬ ‭simple‬‭tissue.‬‭Complex‬‭tissue‬‭are‬‭tissues‬‭which‬‭contain‬‭more‬‭than‬‭one‬‭type‬‭of‬‭cell.‬‭Blood‬‭is‬‭an‬ ‭example‬‭of‬‭complex‬‭tissue.‬ ‭ n‬‭organ‬‭contains‬‭more‬‭than‬‭one‬‭type‬‭of‬‭tissue‬‭which‬‭all‬‭work‬‭together‬‭for‬‭a‬‭specific‬‭function.‬ A ‭The‬‭stomach‬‭contains‬‭gland‬‭tissue,‬‭muscular‬‭tissue,‬‭and‬‭nervous‬‭tissue.‬ ‭ ‬‭(organ)‬‭system‬‭consists‬‭of‬‭several‬‭organs‬‭working‬‭together‬‭for‬‭a‬‭common‬‭purpose.‬‭A‬‭system‬ A ‭in‬‭the‬‭human‬‭body‬‭is‬‭something‬‭such‬‭as‬‭the‬‭digestive‬‭system.‬ ‭An‬‭organism‬‭is‬‭various‬‭systems‬‭working‬‭together‬‭to‬‭make‬‭up‬‭the‬‭entire‬‭body‬‭of‬‭the‬‭organism.‬ ‭ ed‬‭blood‬‭cells‬‭do‬‭not‬‭contain‬‭a‬‭nucleus‬‭to‬‭contain‬‭more‬‭haemoglobin,‬‭not‬‭to‬‭pack‬‭more‬ R ‭oxygen.‬ ‭Two‬‭types‬‭of‬‭cellular‬‭organisations‬‭are‬‭recognised:‬ ‭Prokaryotes‬‭and‬‭Eukaryotes‬ ‭Eukaryotes‬‭are‬‭cells‬‭that‬‭possess‬‭a‬‭nucleus‬‭and‬‭membrane-bound‬‭organelles.‬ ‭ rokaryotes‬‭are‬‭cells‬‭that‬‭do‬‭not‬‭possess‬‭a‬‭membrane‬‭bound‬‭nucleus.‬‭They‬‭are‬‭smaller‬‭than‬ P ‭eukaryotes.‬ ‭As‬‭a‬‭reminder,‬‭plant‬‭cells‬‭aren’t‬‭necessarily‬‭rectangular.‬ ‭Movement‬‭of‬‭Substances‬ ‭An‬‭Overview‬ ‭ he‬‭movement‬‭of‬‭substances‬‭in‬‭and‬‭out‬‭of‬‭cells‬‭across‬‭their‬‭plasma‬‭membranes‬‭has‬‭to‬‭occur‬ T ‭continuously‬‭for‬‭the‬‭functioning‬‭of‬‭living‬‭tissues.‬ ‭The‬‭purpose‬‭of‬‭that‬‭is‬‭to:‬ ‭❡‬‭Allow‬‭entry‬‭of‬‭substances‬‭useful‬‭to‬‭the‬‭cell‬‭such‬‭as‬‭oxygen‬ ‭❡‬‭Remove‬‭excretory‬‭products‬‭from‬‭the‬‭cell‬‭such‬‭as‬‭carbon‬‭dioxide‬ ‭❡‬‭Secretion‬‭of‬‭substances‬‭out‬‭of‬‭the‬‭cell‬‭such‬‭as‬‭hormones‬ ‭Cell‬‭Surface‬‭Membrane‬‭|‬‭Fluid‬‭Mosaic‬‭Model‬ ‭ here‬‭is‬‭a‬‭bilayer‬‭of‬‭phospholipids,‬‭with‬‭hydrophobic‬‭tails‬‭facing‬‭inwards.‬‭Phosphilipids‬‭move‬ T ‭within‬‭the‬‭bilayer,‬‭and‬‭inmobile‬‭proteins‬‭are‬‭embedded‬‭or‬‭attached‬‭to‬‭within‬‭the‬‭bilayer.‬ ‭ hospholipids‬‭have‬‭a‬‭hydrophilic‬‭head‬‭and‬‭a‬‭hydrophobic‬‭tail.‬‭The‬‭phospholipids‬‭also‬‭contain‬ P ‭cholesterol.‬ ‭There‬‭are‬‭two‬‭types‬‭of‬‭membrane‬‭proteins:‬‭Integral/Intrinsic‬‭and‬‭Peripheral/Extrinsic.‬ I‭ntrinsic‬‭membrane‬‭proteins‬‭are‬‭tightly‬‭bound‬‭to‬‭the‬‭phospholipid‬‭bilayer.‬‭Hydrophobic‬‭amino‬ ‭acids‬‭are‬‭in‬‭contact‬‭with‬‭the‬‭hydrophobic‬‭lipids‬‭on‬‭the‬‭bilayer.‬‭Hydrophilic‬‭proteins‬‭are‬‭exposed‬ ‭to‬‭the‬‭aqueous‬‭medium‬‭on‬‭either‬‭side‬‭of‬‭the‬‭membrane.‬ ‭ xtrinsic‬‭membrane‬‭proteins‬‭are‬‭loosely‬‭attached‬‭to‬‭the‬‭membrane‬‭surface,‬‭to‬‭the‬‭exposed‬ E ‭portions‬‭of‬‭integral‬‭proteins.‬ ‭There‬‭are‬‭5‬‭functions‬‭of‬‭membrane‬‭proteins.‬ ‭❡‬‭Transport‬ ‭❡‬‭Enzymatic‬‭reactions‬ ‭❡‬‭Signal‬‭transduction‬ ‭❡‬‭Cell‬‭to‬‭cell‬‭recognition‬ ‭❡‬‭Intercellular‬‭joining‬‭and‬‭adhesion‬ ‭ ransport‬‭proteins‬‭are‬‭involved‬‭in‬‭the‬‭movement‬‭of‬‭specific‬‭molecules‬‭across‬‭the‬‭membrane‬‭by‬ T ‭acting‬‭as‬‭either‬‭channel‬‭or‬‭carrier‬‭proteins.‬ ‭ nzymatic‬‭reaction‬‭proteins‬‭have‬‭their‬‭active‬‭sites‬‭exposed‬‭to‬‭substances‬‭on‬‭either‬‭side‬‭of‬‭the‬ E ‭membrane.‬‭In‬‭some‬‭cases,‬‭the‬‭enzymes‬‭are‬‭organised‬‭as‬‭part‬‭of‬‭a‬‭metabolic‬‭pathway.‬ ‭ ignal‬‭transduction‬‭proteins‬‭act‬‭as‬‭receptors‬‭to‬‭receive‬‭chemical‬‭messengers‬‭such‬‭as‬ S ‭hormones.‬‭Upon‬‭binding‬‭and‬‭receiving‬‭the‬‭signal,‬‭the‬‭protein‬‭will‬‭undergo‬‭a‬‭conformational‬ ‭change‬‭to‬‭relay‬‭the‬‭message‬‭to‬‭the‬‭inside‬‭of‬‭the‬‭cell.‬ ‭For‬‭the‬‭three‬‭routes‬‭that‬‭things‬‭can‬‭pass‬‭through‬‭the‬‭plasma‬‭membrane‬‭of‬‭a‬‭cell:‬ ‭ hrough‬‭the‬‭phospholipid‬‭bilayer‬‭is‬‭for‬‭substances‬‭that‬‭are‬‭fat-soluble‬‭and‬‭not‬‭repelled‬‭by‬ T ‭the‬‭hydrophobic‬‭layer.‬ ‭Through‬‭the‬‭channel‬‭proteins‬‭are‬‭for‬‭water-soluble‬‭molecules‬‭only.‬ ‭ hrough‬‭the‬‭carrier‬‭proteins‬‭are‬‭for‬‭water-soluble‬‭and‬‭water-insoluble‬‭molecules.‬‭It‬‭supports‬ T ‭charged‬‭particles‬‭(Na+,‬‭Ca2+)‬‭and‬‭relatively‬‭large‬‭polar‬‭molecules‬‭(amino‬‭acids,‬‭glycerol).‬ ‭ hannel‬‭proteins‬‭are‬‭categorised‬‭under‬‭facilitated‬‭diffusion.‬‭It‬‭does‬‭not‬‭take‬‭up‬‭energy.‬‭It‬‭only‬ C ‭transports‬‭substances‬‭down‬‭the‬‭concentration‬‭gradient.‬ ‭ arrier‬‭proteins‬‭are‬‭categorised‬‭under‬‭active‬‭transport.‬‭It‬‭takes‬‭up‬‭energy,‬‭but‬‭only‬‭when‬‭the‬ C ‭transportation‬‭of‬‭substances‬‭goes‬‭against‬‭the‬‭concentration‬‭gradient.‬ ‭Carrier‬‭is‬‭much‬‭slower‬‭than‬‭channel.‬ ‭Diffusion‬ ‭ iffusion‬‭is‬‭the‬‭net‬‭movement‬‭of‬‭substances‬‭from‬‭one‬‭place‬‭to‬‭another‬‭place‬‭down‬‭a‬ D ‭concentration‬‭gradient.‬‭It‬‭is‬‭caused‬‭by‬‭particles‬‭(atoms,‬‭molecules,‬‭ions)‬‭bumping‬‭into‬‭each‬ ‭other‬‭and‬‭spreading‬‭outwards.‬ I‭n‬‭a‬‭situation‬‭where‬‭Point‬‭A‬‭is‬‭a‬‭place‬‭where‬‭a‬‭perfume‬‭bottle‬‭was‬‭spilled‬‭and‬‭Point‬‭B‬‭is‬‭a‬‭place‬ ‭where‬‭someone‬‭is‬‭existing.‬‭Gas‬‭particles‬‭are‬‭more‬‭concentrated‬‭at‬‭Point‬‭A‬‭than‬‭at‬‭Point‬‭B.‬ ‭There‬‭is‬‭a‬‭difference‬‭in‬‭concentration.‬‭This‬‭is‬‭the‬‭concentration‬‭gradient.‬‭The‬‭larger‬‭the‬ ‭difference,‬‭the‬‭steeper‬‭the‬‭concentration‬‭gradient,‬‭and‬‭the‬‭faster‬‭particles‬‭would‬‭diffuse‬‭from‬ ‭Point‬‭A‬‭to‬‭Point‬‭B.‬ ‭ ells‬‭at‬‭the‬‭lungs‬‭exchange‬‭oxygen‬‭and‬‭carbon‬‭dioxide‬‭through‬‭the‬‭process‬‭of‬‭diffusion,‬‭and‬‭so‬ C ‭do‬‭root‬‭hair‬‭cells.‬ ‭Osmosis‬ ‭ smosis‬‭is‬‭the‬‭net‬‭movement‬‭of‬‭water‬‭molecules‬‭from‬‭a‬‭solution‬‭of‬‭higher‬‭water‬‭potential‬‭to‬‭a‬ O ‭solution‬‭of‬‭lower‬‭water‬‭potential,‬‭through‬‭a‬‭partially‬‭permeable‬‭membrane.‬‭“Water‬‭potential”‬‭is‬‭a‬ ‭measure‬‭of‬‭the‬‭tendency‬‭of‬‭water‬‭to‬‭move‬‭from‬‭one‬‭place‬‭to‬‭another.‬‭A‬‭dilute‬‭solution‬‭contains‬ ‭more‬‭water‬‭molecules‬‭per‬‭unit‬‭volume‬‭than‬‭a‬‭concentrated‬‭solution‬‭hence‬‭a‬‭dilute‬‭solution‬‭has‬ ‭a‬‭higher‬‭water‬‭potential‬‭than‬‭a‬‭concentrated‬‭solution.‬‭A‬‭water‬‭potential‬‭gradient‬‭is‬‭established‬ ‭when‬‭a‬‭partially‬‭permeable‬‭membrane‬‭separates‬‭two‬‭solutions‬‭of‬‭different‬‭water‬‭potentials.‬ ‭ upposing‬‭that‬‭there‬‭is‬‭a‬‭container‬‭with‬‭two‬‭segments‬‭separated‬‭by‬‭a‬‭partially‬‭permeable‬ S ‭membrane‬‭and‬‭that‬‭the‬‭left‬‭side‬‭is‬‭filled‬‭with‬‭a‬‭10%‬‭sucrose‬‭solution‬‭while‬‭the‬‭right‬‭side‬‭is‬‭filled‬ ‭with‬‭a‬‭5%‬‭sucrose‬‭solution,‬‭water‬‭will‬‭move‬‭to‬‭the‬‭left‬‭side‬‭of‬‭the‬‭container‬‭through‬‭osmosis‬‭due‬ ‭to‬‭the‬‭right‬‭side‬‭having‬‭a‬‭higher‬‭water‬‭potential‬‭than‬‭the‬‭left‬‭side.‬‭It‬‭can‬‭be‬‭said‬‭that‬‭there‬‭was‬‭a‬ ‭net‬‭movement‬‭of‬‭water‬‭from‬‭a‬‭region‬‭of‬‭higher‬‭water‬‭potential‬‭to‬‭a‬‭region‬‭of‬‭lower‬‭water‬ ‭potential‬‭down‬‭the‬‭water‬‭potential‬‭gradient.‬ ‭Surface‬‭Area‬‭to‬‭Volume‬‭Ratio‬‭+‬‭L‬ ‭ s‬‭something‬‭increases‬‭in‬‭volume,‬‭the‬‭surface‬‭area‬‭would‬‭increase‬‭at‬‭a‬‭slower‬‭rate‬‭than‬‭the‬ A ‭volume‬‭since‬‭surface‬‭area‬‭is‬‭in,‬‭for‬‭example,‬‭metre‬‭squared,‬‭while‬‭volume‬‭is‬‭something‬‭such‬‭as‬ ‭metre‬‭cubed.‬‭Cells‬‭will‬‭not‬‭grow‬‭past‬‭a‬‭certain‬‭size‬‭because‬‭of‬‭this.‬ ‭Active‬‭Transport‬ ‭ his‬‭is‬‭the‬‭process‬‭in‬‭which‬‭energy‬‭is‬‭used‬‭to‬‭move‬‭the‬‭particles‬‭of‬‭a‬‭substance‬‭across‬‭a‬ T ‭membrane‬‭against‬‭its‬‭concentration‬‭gradient‬‭from‬‭a‬‭region‬‭of‬‭lower‬‭concentration‬‭to‬‭a‬‭region‬‭of‬ ‭higher‬‭concentration.‬ ‭ ctive‬‭transport‬‭is‬‭performed‬‭by‬‭specific‬‭carrier‬‭proteins‬‭in‬‭the‬‭membrane.‬‭Active‬‭transport‬ A ‭enables‬‭a‬‭cell‬‭to‬‭maintain‬‭internal‬‭concentrations‬‭of‬‭small‬‭molecules‬‭that‬‭differ‬‭from‬ ‭concentrations‬‭in‬‭its‬‭environment.‬‭For‬‭example,‬‭compared‬‭to‬‭its‬‭surroundings,‬‭an‬‭animal‬‭cell‬ ‭has‬‭a‬‭much‬‭higher‬‭concentration‬‭of‬‭K+‬‭ions‬‭and‬‭lower‬‭concentration‬‭of‬‭Na+‬‭ions.‬‭The‬‭carrier‬ ‭protein‬‭known‬‭as‬‭sodium-potassium‬‭pump‬‭therefore‬‭is‬‭maintaining‬‭these‬‭steep‬‭gradients‬‭by‬ ‭pumping‬‭Na+‬‭out‬‭of‬‭the‬‭cells‬‭and‬‭K+‬‭into‬‭the‬‭cells.‬ ‭Cells‬‭and‬‭Water‬‭potential‬ I‭f‬‭an‬‭animal‬‭cell‬‭has‬‭a‬‭higher‬‭water‬‭potential‬‭than‬‭the‬‭surrounding‬‭solution,‬‭water‬‭will‬‭leave‬‭the‬ ‭cell‬‭by‬‭osmosis‬‭through‬‭the‬‭selectively‬‭permeable‬‭membrane.‬‭The‬‭cell‬‭will‬‭shrink,‬‭and‬‭spikes‬ ‭appear‬‭on‬‭the‬‭cell‬‭membrane.‬‭This‬‭is‬‭called‬‭crenation.‬‭(Cremation‬‭is‬‭when‬‭a‬‭human‬‭body’s‬‭cells‬ ‭undergoes‬‭too‬‭much‬‭crenation‬‭and‬‭dies,‬‭and‬‭then‬‭body‬‭getting‬‭buried)‬ I‭f‬‭a‬‭plant‬‭cell‬‭has‬‭a‬‭higher‬‭water‬‭potential‬‭than‬‭the‬‭surrounding‬‭solution,‬‭the‬‭same‬‭will‬‭happen.‬ ‭The‬‭large‬‭central‬‭vacuole‬‭decreases‬‭in‬‭size,‬‭causing‬‭the‬‭cytoplasm‬‭to‬‭shrink‬‭as‬‭well‬‭and‬‭the‬‭cell‬ ‭membrane‬‭pulling‬‭away‬‭from‬‭the‬‭cell‬‭wall.‬‭This‬‭is‬‭called‬‭plasmolysis.‬ I‭f‬‭an‬‭animal‬‭cell‬‭has‬‭a‬‭lower‬‭water‬‭potential‬‭than‬‭the‬‭surrounding‬‭solution,‬‭water‬‭will‬‭enter‬‭the‬ ‭cell‬‭by‬‭osmosis‬‭through‬‭the‬‭selectively‬‭permeable‬‭membrane.‬‭The‬‭cell‬‭will‬‭expand‬‭and‬‭burst.‬‭It‬ ‭happens‬‭because‬‭the‬‭cell‬‭membrane‬‭ruptures‬‭and‬‭there‬‭is‬‭no‬‭cell‬‭wall.‬‭This‬‭is‬‭called‬‭lysis.‬‭(The‬ ‭cell‬‭is‬‭lysed.)‬ I‭f‬‭a‬‭plant‬‭cell‬‭has‬‭a‬‭lower‬‭water‬‭potential‬‭than‬‭the‬‭surrounding‬‭solution,‬‭water‬‭will‬‭enter‬‭the‬‭cell‬ ‭by‬‭osmosis‬‭in‬‭the‬‭same‬‭way.‬‭The‬‭large‬‭central‬‭vacuole‬‭will‬‭increase‬‭in‬‭size,‬‭causing‬‭the‬ ‭cytoplasm‬‭to‬‭be‬‭pushed‬‭against‬‭the‬‭cell‬‭wall,‬‭which‬‭makes‬‭the‬‭cell‬‭turgid.‬‭The‬‭cell‬‭wall‬‭prevents‬ ‭it‬‭from‬‭bursting.‬‭There‬‭isn’t‬‭really‬‭a‬‭name‬‭for‬‭this‬‭so‬‭I’m‬‭gonna‬‭call‬‭this‬‭turgor‬‭pressure.‬ ‭Bulk‬‭Transport‬ ‭ arge‬‭molecules‬‭such‬‭as‬‭proteins‬‭and‬‭polysaccharides‬‭cross‬‭the‬‭cell‬‭membrane‬‭in‬‭bulk‬‭by‬ L ‭mechanisms‬‭that‬‭involve‬‭packaging‬‭into‬‭vesicles.‬‭These‬‭processes‬‭require‬‭energy.‬‭There‬‭are‬ ‭two‬‭types‬‭of‬‭bulk‬‭transport:‬ ‭❡‬‭Endocytosis‬ ‭❡‬‭Exocytosis‬ ‭Exocytosis‬ ‭ ‬‭During‬‭exocytosis,‬‭transport‬‭vesicles‬‭(called‬‭secretory‬‭vesicles‬‭or‬‭Golgi‬ ‭vesicles)‬‭that‬‭budded‬‭from‬‭the‬‭Golgi‬‭Apparatus‬‭move‬‭towards‬‭the‬‭cell‬ ‭surface‬‭membrane.‬ ‭ ‬‭When‬‭the‬‭vesicle‬‭membrane‬‭and‬‭plasma‬‭membrane‬‭come‬‭into‬‭contact,‬ ‭the‬‭two‬‭membranes‬‭fuse.‬‭The‬‭contents‬‭of‬‭the‬‭vesicles‬‭are‬‭released‬‭and‬ ‭the‬‭vesicle‬‭membrane‬‭becomes‬‭part‬‭of‬‭the‬‭plasma‬‭membrane.‬ ‭Extocytosis‬‭involves‬‭vesicles‬‭a‬‭lot.‬ ‭Endocytosis‬ ‭ ndocytosis‬‭ ‬‭During‬‭endocytosis,‬‭particles‬‭are‬‭taken‬‭into‬‭the‬‭cells‬‭through‬‭the‬ E ‭formation‬‭of‬‭new‬‭vesicles.‬‭Particles‬‭that‬‭are‬‭about‬‭to‬‭be‬‭taken‬‭in‬‭or‬‭engulfed‬‭come‬‭into‬ ‭contact‬‭with‬‭the‬‭cell‬‭surface.‬‭The‬‭cell‬‭membrane‬‭invaginates‬‭(folds‬‭inwards)‬‭to‬‭form‬‭a‬ ‭flask-like‬‭depression‬‭around‬‭the‬‭particles‬‭or‬‭the‬‭cell‬‭membrane‬‭extends‬‭outwards‬ ‭forming‬‭extensions‬‭(pseudopodia)‬‭around‬‭the‬‭particles.‬‭Subsequently,‬‭the‬‭depression‬ ‭deepens‬‭and‬‭the‬‭neck‬‭of‬‭the‬‭flask‬‭closes‬‭and‬‭seals‬‭off‬‭the‬‭invagination,‬‭forming‬‭a‬ ‭separate‬‭vesicle‬ ‭There‬‭are‬‭three‬‭types‬‭of‬‭endocytosis.‬‭They‬‭are:‬ ‭❡‬‭Phagocytosis‬ ‭❡‬‭Pinocytosis‬ ‭❡‬‭Receptor-mediated‬‭endocytosis‬ ‭ hagocytosis‬‭refers‬‭to‬‭the‬‭process‬‭which‬‭takes‬‭up‬‭materials‬‭in‬‭solid‬‭form‬‭(such‬‭as‬‭bacteria‬‭or‬ P ‭cells).‬‭Particles‬‭within‬‭the‬‭formed‬‭vesicle‬‭usually‬‭get‬‭digested‬‭by‬‭the‬‭enzymes‬‭in‬‭the‬‭cell.‬ ‭ hagocytosis‬‭is‬‭a‬‭selective‬‭process,‬‭meaning‬‭that‬‭cells‬‭will‬‭only‬‭take‬‭up‬‭specific‬‭particles.‬ P ‭Certain‬‭white‬‭blood‬‭cells‬‭engulf‬‭bacteria.‬ ‭ inocytosis‬‭refers‬‭to‬‭the‬‭process‬‭which‬‭takes‬‭up‬‭material‬‭in‬‭liquid‬‭form,‬‭and‬‭this‬‭is‬ P ‭non-selective‬‭.‬ ‭ eceptor-meditated‬‭endocytosis‬‭refers‬‭to‬‭the‬‭process‬‭in‬‭which‬‭material‬‭is‬‭to‬‭be‬‭taken‬‭up‬‭by‬ R ‭binding‬‭to‬‭the‬‭receptor‬‭proteins‬‭on‬‭the‬‭cell‬‭membrane.‬‭This‬‭is‬‭a‬‭selective‬‭process.‬ ‭Biological‬‭Molecules‬‭-‬‭Nutrients‬ ‭Nutrients‬‭are‬‭categorised‬‭into‬‭multiple‬‭things,‬‭it‬‭includes‬‭things‬‭such‬‭as‬‭food‬‭and‬‭water.‬ ‭Food‬‭is‬‭needed‬‭to:‬ ‭❡‬‭Provide‬‭energy‬‭for‬‭vital‬‭activities‬ ❡ ‭ ‬‭Supply‬‭raw‬‭materials‬‭to‬‭make‬‭new‬‭protoplasm‬‭for‬‭cell‬‭growth,‬‭reproduction,‬‭and‬‭repair‬‭for‬ ‭worn-out‬‭tissues‬ ‭❡‬‭Help‬‭organisms‬‭stay‬‭healthy‬ ‭❡‬‭Sustain‬‭one’s‬‭drug‬‭addiction‬ ‭ here‬‭are‬‭three‬‭types‬‭of‬‭nutrients.‬‭Nutrients‬‭are‬‭chemical‬‭substances‬‭in‬‭the‬‭food‬‭that‬‭we‬‭eat.‬‭It‬ T ‭includes‬‭carbohydrates‬‭,‬‭fats‬‭,‬‭and‬‭proteins‬‭.‬ ‭Water‬‭is‬‭vital‬‭for‬‭all‬‭body‬‭tissues‬‭in‬‭an‬‭organism.‬‭Water‬‭is‬‭needed‬‭to:‬ ‭❡‬‭Be‬‭a‬‭solvent‬‭for‬‭chemical‬‭reactions‬ ‭❡‬‭Be‬‭a‬‭key‬‭component‬‭of‬‭tissues‬ ‭❡‬‭Control‬‭body‬‭temperature‬ ‭❡‬‭Transporting‬‭dissolved‬‭substances‬ ‭ ater‬‭transports‬‭dissolved‬‭substances‬‭as‬‭the‬‭role‬‭of‬‭a‬‭solvent.‬‭The‬‭dissolved‬‭substances‬ W ‭include‬‭digested‬‭products‬‭and‬‭waste‬‭products.‬ ‭In‬‭plants,‬‭water‬ ‭ iving‬‭organisms‬‭are‬‭made‬‭up‬‭of‬‭chemicals‬‭based‬‭mostly‬‭on‬‭carbon‬‭.‬‭Water‬‭lacks‬‭carbon‬‭and‬‭is‬ L ‭inorganic.‬‭Carbon‬‭enters‬‭the‬‭biosphere‬‭through‬‭photosynthesis‬‭where‬‭carbon‬‭dioxide‬‭in‬‭the‬ ‭atmosphere‬‭is‬‭converted‬‭to‬‭carbohydrates.‬ ‭ arbohydrates,‬‭Lipids,‬‭Proteins,‬‭and‬‭Nucleic‬‭acids‬‭distinguish‬‭living‬‭things‬‭from‬‭inanimate‬ C ‭materials.‬‭It‬‭consists‬‭of‬‭carbon‬‭and‬‭something‬‭else,‬‭which‬‭includes‬‭hydrogen,‬‭oxygen,‬‭nitrogen,‬ ‭sulfur,‬‭or‬‭phosphorus.‬ ‭Carbohydrates‬ ‭ hese‬‭carbohydrates‬‭have‬‭the‬‭chemical‬‭formula‬‭of‬‭CnH2mOm.‬‭It‬‭includes‬‭simple‬‭sugars,‬ T ‭double‬‭sugars,‬‭and‬‭complex‬‭sugars.‬ ‭ imple‬‭sugars‬‭are‬‭called‬‭monosaccharides‬‭and‬‭they‬‭have‬‭molecular‬‭formulas‬‭that‬‭are‬‭multiple‬ S ‭of‬‭the‬‭unit‬‭CH2O.‬‭They‬‭all‬‭have‬‭the‬‭formula‬‭C6H12O6.‬‭Glucose‬‭(which‬‭is‬‭an‬‭example‬‭of‬‭this)‬‭is‬ ‭the‬‭substrate‬‭in‬‭cellular‬‭respiration.‬ ‭ ouble‬‭sugars‬‭are‬‭called‬‭disaccharides‬‭and‬‭they‬‭are‬‭formed‬‭when‬‭two‬‭monosaccharides‬‭are‬ D ‭joined‬‭together.‬‭Maltose‬‭is‬‭formed‬‭by‬‭joining‬‭together‬‭2‬‭glucose‬‭molecules,‬‭sucrose‬‭is‬‭formed‬ ‭by‬‭joining‬‭together‬‭1‬‭glucose‬‭and‬‭1‬‭fructose,‬‭lactose‬‭is‬‭formed‬‭by‬‭joining‬‭together‬‭1‬‭glucose‬‭and‬ ‭1‬‭galactose.‬ ‭Students‬‭need‬‭to‬‭recognise‬‭these:‬ ‭A‬‭disaccharide‬‭can‬‭be‬‭hydrolysed‬‭(split)‬‭to‬‭form‬‭two‬‭monosaccharides.‬ ‭ omplex‬‭carbohydrates‬‭are‬‭called‬‭polysaccharides‬‭.‬‭They‬‭are‬‭made‬‭up‬‭of‬‭many‬‭similar‬ C ‭molecules‬‭of‬‭single‬‭sugars‬‭joined‬‭together‬‭to‬‭form‬‭a‬‭large‬‭molecule.‬ ‭Fat‬ ‭ ats‬‭or‬‭lipids‬‭contain‬‭carbon,‬‭hydrogen,‬‭and‬‭oxygen.‬‭The‬‭proportion‬‭of‬‭hydrogen‬‭to‬‭oxygen‬‭is‬ F ‭not‬‭fixed.‬‭It‬‭contains‬‭much‬‭less‬‭oxygen‬‭in‬‭proportion‬‭to‬‭hydrogen.‬ ‭ ats‬‭are‬‭mostly‬‭hydrocarbons‬‭which‬‭form‬‭nonpolar‬‭covalent‬‭bonds,‬‭hence‬‭they‬‭are‬‭mostly‬‭or‬ F ‭entirely‬‭hydrophobic‬‭(no‬‭affinity‬‭for‬‭water).‬‭A‬‭fat‬‭molecule‬‭is‬‭formed‬‭from‬‭two‬‭kinds‬‭of‬‭smaller‬ ‭molecules:‬‭glycerol‬‭and‬‭fatty‬‭acids.‬‭In‬‭a‬‭fat‬‭molecule,‬‭three‬‭fatty‬‭acids‬‭are‬‭joined‬‭to‬‭one‬‭glycerol‬ ‭by‬‭an‬‭ester‬‭linkage,‬‭forming‬‭a‬‭triglyceride.‬‭Most‬‭animal‬‭fats‬‭are‬‭saturated.‬‭Saturated‬‭fats‬‭are‬ ‭solid‬‭at‬‭room‬‭temperature‬‭while‬‭“plant‬‭and‬‭fish”‬‭unsaturated‬‭fats‬‭(AKA‬‭oils)‬‭are‬‭liquid‬‭at‬‭room‬ ‭temperature,‬‭where‬‭kinks‬‭caused‬‭by‬‭cis‬‭double‬‭bonds‬‭prevent‬‭the‬‭molecules‬‭from‬‭packing‬ ‭tightly‬‭enough‬‭such‬‭that‬‭they‬‭are‬‭a‬‭solid‬‭at‬‭room‬‭temperature.‬ ‭The‬‭functions‬‭of‬‭fats‬‭are‬‭below:‬ ‭❡‬‭Storage‬‭of‬‭energy‬  ‭‬ A ‭ ‬‭gram‬‭of‬‭fat‬‭contains‬‭more‬‭than‬‭twice‬‭the‬‭energy‬‭of‬‭a‬‭gram‬‭of‬‭polysaccharides.‬‭Plants‬ ‭use‬‭oils‬‭when‬‭dispersal‬‭and‬‭compact‬‭storage‬‭are‬‭important,‬‭such‬‭as‬‭in‬‭seeds.‬‭Animals‬ ‭carry‬‭energy‬‭stores‬‭with‬‭them,‬‭so‬‭they‬‭benefit‬‭from‬‭having‬‭a‬‭more‬‭compact‬‭fuel‬‭reservoir‬ ‭of‬‭fat.‬‭Humans‬‭and‬‭other‬‭mammals‬‭store‬‭fats‬‭as‬‭long-term‬‭energy‬‭reserves‬‭in‬‭adipose‬ ‭cells‬‭that‬‭swell‬‭and‬‭shrink‬‭as‬‭fat‬‭is‬‭deposited‬‭and‬‭withdrawn‬‭from‬‭storage.‬ ‭❡‬‭Cushion‬‭vital‬‭organs‬‭(such‬‭as‬‭kidneys)‬ ‭❡‬‭Insulation‬ ‭Proteins‬ ‭ hese‬‭things‬‭are‬‭made‬‭up‬‭of‬‭the‬‭following‬‭elements:‬‭Hydrogen,‬‭Oxygen,‬‭Nitrogen,‬‭Carbon,‬‭and‬ T ‭Sulfur.‬ ‭ he‬‭basic‬‭unit‬‭of‬‭protein‬‭is‬‭the‬‭amino‬‭acid.‬‭20‬‭naturally-occurring‬‭ones‬‭are‬‭known.‬‭Amino‬‭acids‬ T ‭are‬‭joined‬‭using‬‭peptide‬‭bonds.‬‭Short-chain‬‭proteins‬‭are‬‭called‬‭polypeptides.‬ ‭Proteins‬‭function‬‭for:‬ ‭❡‬‭Synthesis‬‭of‬‭new‬‭protoplasm‬‭for‬‭growth‬‭and‬‭repair‬‭of‬‭worn-out‬‭parts‬‭of‬‭the‬‭body‬ ‭❡‬‭Synthesis‬‭of‬‭enzymes‬ ‭❡‬‭Synthesis‬‭of‬‭hormones‬ ‭❡‬‭Formation‬‭of‬‭haemoglobin‬ ‭❡‬‭Formation‬‭of‬‭antibodies‬‭(to‬‭defend‬‭against‬‭foreign‬‭substances)‬ ‭❡‬‭Formation‬‭of‬‭support‬‭structures‬‭(eg.‬‭silk,‬‭webs,‬‭collagen,‬‭keratin)‬ ‭❡‬‭Formation‬‭of‬‭storage‬‭structures‬‭(eg.‬‭ovalbumin,‬‭casein)‬ ‭❡‬‭Membrane‬‭proteins‬‭which‬‭move‬‭across‬‭the‬‭phospholipid‬‭bilayer‬ ‭Nucleic‬‭Acids‬ ‭ ucleic‬‭acids‬‭consist‬‭of‬‭Hydrogen,‬‭Oxygen,‬‭Nitrogen,‬‭Carbon,‬‭and‬‭Phosphorus‬‭.‬‭Nucleic‬‭acids‬ N ‭consist‬‭of‬‭nucleotides‬‭.‬‭Nucleic‬‭acids‬‭are‬‭polymers,‬‭while‬‭nucleic‬‭acids‬‭are‬‭monomers.‬ ‭All‬‭nucleotides‬‭consist‬‭of:‬ ‭❡‬‭A‬‭pentose‬‭sugar‬ ‭❡‬‭A‬‭nitrogenous‬‭base‬ ‭❡‬‭A‬‭phosphate‬‭group‬ ‭ here‬‭are‬‭two‬‭different‬‭types‬‭of‬‭nucleic‬‭acids:‬‭DNA‬‭(Deoxyribonucleic‬‭acid),‬‭and‬‭RNA‬ T ‭(Ribonucleic‬‭acid).‬‭DNA‬‭has‬‭a‬‭double‬‭helix‬‭structure‬‭while‬‭RNA‬‭has‬‭a‬‭single-stranded‬‭structure.‬ ‭DNA‬‭consists‬‭of‬‭nitrogenous‬‭bases‬‭Adenine‬‭,‬‭Guanine‬‭,‬‭Cytosine‬‭,‬‭and‬‭Thymine‬‭.‬‭In‬‭RNA,‬ ‭Thymine‬‭is‬‭replaced‬‭by‬‭Uracil‬‭.‬ ‭Tests‬ ‭ enedict’s‬‭test‬‭for‬‭reducing‬‭sugars,‬‭Iodine‬‭test‬‭for‬‭starch,‬‭Biuret‬‭test‬‭for‬‭protein,‬‭Ethanol‬ B ‭emulsion‬‭test‬‭for‬‭fats.‬ ‭Benedict’s‬‭Test‬‭in‬‭a‬‭nutshell‬ ‭ he‬‭first‬‭2‬‭steps‬‭for‬‭solid‬‭samples‬‭are‬‭to‬‭reduce‬‭the‬‭food‬‭to‬‭atoms‬‭extract‬‭reducing‬‭sugars‬ T ‭from‬‭the‬‭solids‬‭and‬‭to‬‭put‬‭them‬‭in‬‭a‬‭solvent.‬ ‭Steps‬‭4‬‭and‬‭5‬‭are‬‭meant‬‭to‬‭heat‬‭up‬‭everything‬‭such‬‭at‬‭the‬‭results‬‭of‬‭Benedict’s‬‭test‬‭are‬‭visible.‬ ‭1.‬ ‭Solid‬‭only:‬‭Place‬‭1cm3‬‭of‬‭the‬‭crushed‬‭food‬‭sample‬‭into‬‭a‬‭test‬‭tube.‬ ‭2.‬ S ‭ olid‬‭only:‬‭Add‬‭2cm3‬‭of‬‭water‬‭into‬‭the‬‭test‬‭tube‬‭to‬‭dissolve‬‭the‬‭reducing‬‭sugars‬‭into‬‭the‬ ‭sample‬‭.‬‭Decant.‬ ‭3.‬ ‭Place‬‭2cm3‬‭of‬‭Benedict’s‬‭solution‬‭into‬‭the‬‭test‬‭tube‬‭sample,‬‭shake‬‭thoroughly‬‭to‬‭mix‬‭.‬ ‭4.‬ ‭Place‬‭tube‬‭in‬‭boiling‬‭water‬‭bath‬‭for‬‭2-3‬‭minutes.‬ ‭5.‬ ‭Remove‬‭the‬‭tubes‬‭from‬‭the‬‭bath‬‭after‬‭2-3‬‭minutes.‬ ‭6.‬ ‭Observe‬‭and‬‭record‬‭changes‬‭in‬‭colour‬‭of‬‭the‬‭mixture‬‭if‬‭any.‬ ‭7.‬ I‭f‬‭the‬‭solution‬‭turned‬‭from‬‭blue‬‭to‬‭brick-red‬‭with‬‭precipitate,‬‭large‬‭amounts‬‭of‬‭reducing‬ ‭sugars‬‭are‬‭present.‬ I‭f‬‭the‬‭solution‬‭turned‬‭from‬‭blue‬‭to‬‭orange‬‭or‬‭yellow,‬‭a‬‭moderate‬‭amount‬‭of‬‭reducing‬ ‭sugars‬‭are‬‭present.‬‭If‬‭the‬‭solution‬‭turned‬‭from‬‭blue‬‭to‬‭green,‬‭trace‬‭amounts‬‭of‬‭reducing‬ ‭sugars‬‭are‬‭present.‬‭If‬‭the‬‭solution‬‭remained‬‭blue,‬‭reducing‬‭sugars‬‭are‬‭absent.‬ ‭If‬‭non-reducing‬‭sugars‬‭are‬‭present,‬‭the‬‭following‬‭follow-up‬‭test‬‭can‬‭be‬‭done:‬ ‭1.‬ ‭(Test‬‭for‬‭reducing‬‭sugars.‬‭If‬‭reducing‬‭sugars‬‭are‬‭absent:)‬ ‭Use‬‭a‬‭fresh‬‭sample‬‭solution‬‭and‬‭heat‬‭the‬‭sample‬‭in‬‭a‬‭boiling‬‭water‬‭bath‬‭with‬‭2cm3‬‭of‬ ‭ ydrochloric‬‭acid.‬ h  ‭2.‬ ‭Neutralise‬‭with‬‭sodium‬‭hydrogen‬‭carbonate‬‭.‬ ‭3.‬ ‭Perform‬‭Benedict’s‬‭test‬‭for‬‭reducing‬‭sugars.‬ ‭Note‬‭:‬‭Hydrochloric‬‭acid‬‭hydrolyses‬‭the‬‭glycosidic‬‭bonds.‬ ‭Iodine‬‭Test‬‭for‬‭Starch‬ ‭The‬‭1st‬‭step‬‭for‬‭solid‬‭samples‬‭is‬‭to‬‭get‬‭ready‬‭the‬‭food‬‭for‬‭placing‬‭iodine‬‭on.‬ ‭1.‬ ‭Solid‬‭only:‬‭Place‬‭1cm3‬‭of‬‭the‬‭crushed‬‭food‬‭sample‬‭onto‬‭a‬‭white‬‭tile.‬ ‭2.‬ A ‭ dd‬‭2‬‭drops‬‭of‬‭iodine‬‭solution‬‭onto‬‭the‬‭sample‬‭solution‬‭(liquid)‬‭/‬‭onto‬‭the‬‭crushed‬‭food‬ ‭sample.‬‭(solid)‬ ‭3.‬ ‭Observe‬‭and‬‭record‬‭changes‬‭in‬‭the‬‭colour‬‭of‬‭the‬‭iodine‬‭solution‬ ‭4.‬ ‭If‬‭the‬‭solution‬‭turns‬‭from‬‭brown‬‭to‬‭blue-black,‬‭starch‬‭is‬‭present‬‭in‬‭the‬‭sample.‬ ‭If‬‭the‬‭solution‬‭remains‬‭brown,‬‭starch‬‭is‬‭absent‬‭in‬‭the‬‭sample.‬ ‭Biuret‬‭Test‬‭for‬‭proteins‬ ‭Same‬‭thing‬‭for‬‭solids,‬‭extra‬‭steps‬‭at‬‭the‬‭beginning.‬ ‭1.‬ ‭Solid‬‭only:‬‭Place‬‭the‬‭crushed‬‭food‬‭into‬‭a‬‭clean‬‭test‬‭tube,‬‭label‬‭the‬‭tube‬‭appropriately.‬ ‭2.‬ ‭Solid‬‭only:‬‭Add‬‭2cm3‬‭of‬‭water‬‭to‬‭the‬‭crushed‬‭sample.‬‭Shake‬‭thoroughly‬‭to‬‭mix,‬‭decant.‬ ‭3.‬ F ‭ or‬‭solids:‬‭Add‬‭equal‬‭volume‬‭of‬‭sodium‬‭hydroxide‬‭solution‬‭to‬‭the‬‭solution.‬‭Shake‬ ‭thoroughly‬‭to‬‭mix.‬‭For‬‭liquids:‬‭To‬‭2cm3‬‭of‬‭liquid,‬‭add‬‭2cm3‬‭of‬‭sodium‬‭hydroxide‬ ‭solution.‬‭Shake‬‭thoroughly‬‭to‬‭mix.‬ ‭4.‬ ‭Add‬‭in‬‭1%‬‭copper‬‭sulfate‬‭solution‬‭,‬‭drop‬‭by‬‭drop.‬‭Shake‬‭the‬‭test‬‭tube‬‭after‬‭every‬‭drop.‬ ‭5.‬ ‭Observe‬‭and‬‭record‬‭changes.‬ ‭6.‬ ‭If‬‭the‬‭solution‬‭turns‬‭from‬‭blue‬‭to‬‭violet,‬‭proteins‬‭are‬‭present.‬ ‭If‬‭the‬‭solution‬‭remains‬‭blue,‬‭proteins‬‭are‬‭absent.‬ ‭Ethanol‬‭Emulsion‬‭Test‬‭for‬‭lipids‬  ‭1.‬ ‭Solids‬‭only:‬‭Place‬‭1cm3‬‭of‬‭crushed‬‭food‬‭into‬‭a‬‭test‬‭tube,‬‭label‬‭appropriately.‬ ‭2.‬ F ‭ or‬‭solids:‬‭Add‬‭3cm3‬‭of‬‭ethanol‬‭into‬‭the‬‭sample,‬‭shake‬‭thoroughly‬‭to‬‭mix‬‭For‬‭liquids:‬‭To‬ ‭some‬‭drops‬‭of‬‭liquids‬‭(usually‬‭oil),‬‭add‬‭1cm3‬‭of‬‭ethanol,‬‭shake‬‭thoroughly‬‭to‬‭mix.‬ ‭3.‬ ‭Solids‬‭only:‬‭Record‬‭changes‬‭in‬‭the‬‭solution.‬ ‭4.‬ ‭Solids‬‭only:‬‭Decant‬‭1cm3‬‭of‬‭the‬‭mixture‬‭to‬‭another‬‭test‬‭tube.‬ ‭5.‬ F ‭ or‬‭solids:‬‭Add‬‭an‬‭equal‬‭amount‬‭of‬‭water‬‭into‬‭the‬‭liquid‬‭portion.‬‭Observe‬‭and‬‭record‬‭the‬ ‭formation‬‭of‬‭a‬‭white‬‭emulsion.‬‭For‬‭liquids:‬‭Add‬‭1cm3‬‭of‬‭water‬‭to‬‭the‬‭liquid‬‭portion.‬ ‭Observe‬‭and‬‭record‬‭the‬‭formation‬‭of‬‭a‬‭white‬‭emulsion.‬ ‭6.‬ ‭If‬‭a‬‭white‬‭emulsion‬‭is‬‭formed,‬‭lipids‬‭are‬‭present.‬ ‭If‬‭a‬‭white‬‭emulsion‬‭is‬‭not‬‭formed,‬‭lipids‬‭are‬‭absent.‬ ‭TA1‬‭Preparation:‬‭Answering‬‭Techniques‬ ‭Red‬‭text‬‭indicates‬‭that‬‭there‬‭was‬‭a‬‭mistake.‬ ‭Untitled‬ ‭Worksheet‬‭2‬‭-‬‭Movement‬‭of‬‭Substances‬ ‭1aii‬‭-‬‭(protein‬‭channel)‬ ‭ :‬‭Facilitates‬‭movement‬‭of‬‭specific‬‭molecules‬‭across‬‭the‬‭membrane‬‭by‬‭acting‬‭as‬‭a‬‭channel‬‭or‬ K ‭carrier‬‭protein.‬ ‭ issing:‬‭“Facilitated‬‭diffusion”,‬‭specification‬‭of‬‭molecules‬‭[eg.‬‭ions,‬‭small‬‭water‬‭soluble‬ M ‭molecules]‬ ‭L:‬‭“To‬‭act‬‭as‬‭an‬‭enzyme”‬ ‭ orrect‬‭answer:‬‭Cell‬‭recognition,‬‭surface‬‭antigen,‬‭binding‬‭site;‬‭forms‬‭hydrogen‬‭bonds‬‭with‬‭water‬ C ‭to‬‭stabilise‬‭membrane‬‭structure‬ ‭ :‬‭Phospholipids‬‭act‬‭as‬‭a‬‭boundary‬‭to‬‭protect‬‭the‬‭cell‬‭from‬‭the‬‭external‬‭environment‬‭as‬‭well‬‭as‬ M ‭to‬‭facilitate‬‭exocytosis.‬‭(This‬‭is‬‭correct)‬ ‭1c‬‭-‬‭Graph,‬‭y-axis‬‭is‬‭rate‬‭of‬‭uptake‬‭of‬‭glucose,‬‭x-axis‬‭is‬‭concentration‬‭of‬‭glucose‬ ‭ xplain‬‭how‬‭the‬‭results‬‭of‬‭the‬‭investigation‬‭support‬‭the‬‭idea‬‭that‬‭glucose‬‭enters‬‭cells‬‭by‬ E ‭faciliated‬‭diffusion.‬ ‭ issing:‬‭Rate‬‭of‬‭intake‬‭increases‬‭with‬‭increasing‬‭glucose‬‭concentration‬‭up‬‭until‬‭a‬‭constant‬‭rate‬ M ‭is‬‭reached;‬‭With‬‭passive‬‭diffusion,‬‭it‬‭would‬‭continue‬‭rising‬ ‭ uggested‬‭answer:‬‭The‬‭constant‬‭increase‬‭of‬‭rate‬‭of‬‭intake‬‭of‬‭glucose‬‭slows‬‭down‬‭to‬‭a‬‭constant‬ S ‭rate‬‭by‬‭30‬‭arbitrary‬‭units‬‭of‬‭glucose‬‭concentration.‬‭It‬‭supports‬‭the‬‭idea‬‭that‬‭glucose‬‭enters‬‭by‬ ‭facilitated‬‭diffusion‬‭because‬‭regular‬‭diffusion‬‭would‬‭cause‬‭the‬‭rate‬‭to‬‭continue‬‭increasing.‬ ‭Facilitated‬‭diffusion‬‭has‬‭a‬‭limit‬‭to‬‭the‬‭rate‬‭of‬‭diffusion.‬ ‭ b‬‭-‬‭Name‬‭and‬‭describe‬‭the‬‭function‬‭of‬‭the‬‭transport‬‭protein‬‭responsible‬‭for‬‭the‬‭entry‬‭of‬ 2 ‭water‬‭into‬‭the‬‭plant‬‭cell.‬ ‭Missing:‬‭The‬‭question‬‭was‬‭left‬‭blank‬‭so-‬ ‭(oh‬‭well)‬ ‭ nswer:‬‭Aquaporins,‬‭which‬‭provide‬‭a‬‭hydrophilic‬‭channel‬‭for‬‭water‬‭molecules‬‭to‬‭enter‬‭via‬ A ‭osmosis.‬ (‭ Aquaporins‬‭facilitate‬‭the‬‭movement‬‭of‬‭water‬‭molecules‬‭across‬‭the‬‭membranes‬‭of‬‭animal‬‭and‬ ‭plant‬‭cells.)‬ ‭3aii‬‭-‬‭State‬‭two‬‭types‬‭of‬‭materials‬‭that‬‭can‬‭be‬‭taken‬‭in‬‭via‬‭endocytosis‬ ‭Incorrect:‬‭proteins,‬‭polysaccharides‬ ‭Correct:‬‭charged‬‭particles,‬‭hydrophilic‬‭particles‬ ‭ bi‬‭-‬‭Explain‬‭why‬‭the‬‭absorption‬‭of‬‭nitrate‬‭ions‬‭by‬‭the‬‭plants‬‭in‬‭batch‬‭N‬‭differs‬‭from‬‭that‬ 5 ‭in‬‭batch‬‭P.‬ ‭Missing:‬‭How‬‭does‬‭batch‬‭P‬‭take‬‭up‬‭ions?‬ ‭1‬‭ions‬‭/‬‭minerals‬‭/‬‭nitrates‬‭in‬‭batch‬‭P‬‭are‬‭absorbed‬‭(only)‬‭by‬‭diffusion‬ ‭2‬‭no‬‭/‬‭limited‬‭/‬‭less,‬‭energy‬‭for‬‭active‬‭absorption‬‭/‬‭transport‬ ‭3‬‭because‬‭(cyanide)‬‭inhibits,‬‭respiration‬‭/‬‭ATP‬‭synthesis‬ ‭4‬‭ions‬‭in‬‭batch‬‭N‬‭are‬‭absorbed‬‭by‬‭active‬‭transport‬‭(and‬‭diffusion)‬ ‭5‬‭(idea‬‭of)‬‭after‬‭10‬‭hours‬‭no‬‭concentration‬‭gradient‬‭in‬‭P‬ ‭6‬‭as‬‭rate‬‭of‬‭assimilation‬‭/‬‭use‬‭=‬‭rate‬‭of‬‭absorption‬‭(so‬‭concentration‬‭in‬‭plant‬‭remains‬‭constant)‬ ‭7‬‭active‬‭transport‬‭continues‬‭in‬‭N‬‭against‬‭a‬‭concentration‬‭gradient‬‭(after‬‭10‬‭hours)‬ ‭8‬‭ref.‬‭to‬‭appropriate‬‭figs‬‭(linked‬‭to‬‭an‬‭explanation‬‭of‬‭different‬‭absorption‬‭rates)‬ ‭Worksheet‬‭3‬‭-‬‭Biological‬‭Molecules‬‭Nutrients‬ ‭ aii‬‭-‬‭You‬‭could‬‭use‬‭the‬‭test‬‭to‬‭compare‬‭the‬‭amount‬‭of‬‭reducing‬‭sugar‬‭in‬‭two‬‭different‬ 3 ‭brands‬‭of‬‭the‬‭nutrition‬‭supplement‬‭drinks.‬‭Suggest‬‭how‬‭the‬‭test‬‭can‬‭be‬‭used‬‭as‬‭a‬ ‭semi-quantitative.‬ ‭Structure:‬‭Compare‬‭results‬‭and‬‭colour‬‭of‬‭mixture,‬‭list‬‭colour‬‭outcomes,‬‭list‬‭quantitative‬‭action.‬ ‭Missing:‬‭If‬‭it‬‭is‬‭the‬‭same‬‭colour,‬‭compare‬‭the‬‭mass‬‭of‬‭precipitate‬‭formed.‬ ‭ aiii‬‭-‬‭Describe‬‭how‬‭the‬‭structure‬‭of‬‭cellulose‬‭makes‬‭it‬‭suitable‬‭for‬‭its‬‭function‬‭in‬‭cell‬ 3 ‭walls‬ ‭Missing:‬‭Long‬‭unbranched‬‭chains‬ ‭Questions‬‭down‬‭below:‬ ‭Describe‬‭the‬‭structure‬‭of‬‭the‬‭endoplasmic‬‭reticulum.‬ ‭ nswer:‬‭The‬‭rough‬‭endoplasmic‬‭reticulum‬‭has‬‭an‬‭outer‬‭layer‬‭that‬‭is‬‭covered‬‭in‬‭ribosomes.‬‭The‬ A ‭ribosome‬‭membrane‬‭is‬‭part‬‭of‬‭the‬‭nuclear‬‭membrane.‬‭The‬‭smooth‬‭endoplasmic‬‭reticulum‬‭is‬‭not‬ ‭covered‬‭in‬‭ribisomes,‬‭and‬‭is‬‭more‬‭tubular‬‭.‬ ‭Describe‬‭the‬‭structure‬‭of‬‭the‬‭nucleus.‬ ‭ nswer:‬‭The‬‭nuclear‬‭membrane‬‭surrounds‬‭the‬‭nucleoplasm‬‭.‬‭The‬‭nuclear‬‭membrane‬‭consists‬ A ‭of‬‭two‬‭membranes.‬‭One‬‭of‬‭which‬‭is‬‭continuous‬‭with‬‭the‬‭endoplasmic‬‭reticulum.‬‭The‬‭nuclear‬ ‭membrane‬‭is‬‭peforated‬‭with‬‭pores‬‭to‬‭control‬‭the‬‭movement‬‭of‬‭substances‬‭in‬‭and‬‭out‬‭of‬‭the‬ ‭nucleus.‬ ‭Describe‬‭the‬‭function‬‭of‬‭the‬‭golgi‬‭body.‬ ‭ nswer:‬‭The‬‭golgi‬‭body‬‭chemically‬‭modifies‬‭substances‬‭manufactured‬‭by‬‭the‬‭endoplasmic‬ A ‭reticulum‬‭and‬‭stores‬‭and‬‭secretes‬‭them‬‭out‬‭of‬‭the‬‭cell‬‭using‬‭golgi‬‭vesicles.‬ ‭Describe‬‭the‬‭function‬‭of‬‭the‬‭golgi‬‭vesicle.‬ ‭ nswer:‬‭Golgi‬‭vesicles‬‭are‬‭responsible‬‭for‬‭transporting‬‭substances‬‭chemically‬‭modified‬‭by‬‭the‬ A ‭golgi‬‭body‬‭out‬‭of‬‭the‬‭cell‬‭via‬‭exocytosis.‬ ‭Explain‬‭why‬‭this‬‭is‬‭known‬‭as‬‭the‬‭fluid‬‭mosaic‬‭model.‬ ‭Answer:‬‭The‬‭phospholipids‬‭move‬‭freely‬‭within‬‭the‬‭bilayer‬ ‭Why‬‭did‬‭the‬‭potato‬‭gain‬‭in‬‭mass?‬‭(It‬‭was‬‭placed‬‭in‬‭water)‬ ‭ nswer:‬‭The‬‭potato‬‭was‬‭placed‬‭in‬‭a‬‭solution‬‭which‬‭had‬‭a‬‭higher‬‭water‬‭potential‬‭than‬‭itself.‬ A ‭Water‬‭travelled‬‭from‬‭the‬‭water‬‭(higher‬‭concentration)‬‭to‬‭the‬‭potato‬‭(lower‬‭concentration)‬‭by‬ ‭osmosis‬‭through‬‭the‬‭partially‬‭permeable‬‭cell‬‭membranes‬‭of‬‭the‬‭potato,‬‭down‬‭the‬‭concentration‬ ‭gradient‬‭until‬‭equilibrium‬‭was‬‭reached.‬‭The‬‭potato‬‭cells‬‭contained‬‭more‬‭water‬‭than‬‭it‬‭did‬‭before,‬ ‭therefore‬‭it‬‭gained‬‭in‬‭mass.‬ ‭What‬‭is‬‭the‬‭difference‬‭between‬‭channel‬‭and‬‭carrier‬‭proteins‬‭in‬‭function?‬ ‭Answer:‬‭Channel‬‭proteins‬‭creates‬‭a‬‭hydrophilic‬‭channel‬‭for‬‭water-insoluble‬‭molecul‬ ‭What‬‭are‬‭the‬‭types‬‭of‬‭endocytosis?‬‭Describe‬‭and‬‭explain‬ ‭Describe‬‭the‬‭Biuret‬‭Test‬ ‭Nutrition‬‭in‬‭Humans‬ ‭Basic‬‭overview‬ ‭There‬‭are‬‭two‬‭types‬‭of‬‭nutrition:‬‭Autoprophic‬‭and‬‭Heterotrophic.‬ ‭ n‬‭Autotroph‬‭is‬‭an‬‭organism‬‭which‬‭can‬‭produce‬‭its‬‭own‬‭food‬‭using‬‭light,‬‭water,‬‭carbon‬‭dioxide,‬ A ‭or‬‭other‬‭chemicals.‬‭Most‬‭use‬‭photosynthesis‬‭to‬‭synthesize‬‭food.‬ ‭ ‬‭Heterotroph‬‭is‬‭an‬‭organism‬‭that‬‭is‬‭unable‬‭to‬‭produce‬‭organic‬‭substances‬‭from‬‭inorganic‬‭ones‬ A ‭and‬‭depend‬‭indirectly‬‭or‬‭directly‬‭on‬‭autotrophs‬‭for‬‭nutrients‬‭and‬‭energy.‬ ‭Digestive‬‭System,‬‭Alimentary‬‭Canal,‬‭Accessory‬‭organs‬ ‭ he‬‭himan‬‭digestive‬‭system‬‭consists‬‭of‬‭the‬‭alimentary‬‭canal‬‭and‬‭various‬‭accessory‬‭glands.‬ T ‭Accessory‬‭glands‬‭include‬‭the‬‭salivary‬‭glands,‬‭pancreas,‬‭liver,‬‭and‬‭gall‬‭bladder.‬ ‭Mouth,‬‭Buccal‬‭Cavity,‬‭Salivary‬‭Glands‬ ‭ hysical‬‭and‬‭Chemical‬‭digestion‬‭of‬‭food‬‭begins‬‭in‬‭the‬‭buccal‬‭cavity.‬‭Teech‬‭cut,‬‭grind,‬‭and‬‭break‬ P ‭up‬‭food‬‭during‬‭chewing.‬‭This‬‭increases‬‭the‬‭surface‬‭area‬‭of‬‭food‬‭exposed‬‭to‬‭digestive‬‭enzymes.‬ ‭ he‬‭presence‬‭of‬‭food‬‭trivggers‬‭a‬‭nervous‬‭reflex‬‭which‬‭causes‬‭the‬‭salivary‬‭glands‬‭to‬‭secrete‬ T ‭saliva‬‭through‬‭salivary‬‭ducts‬‭to‬‭the‬‭buccal‬‭cavity.‬‭Saliva‬‭contains‬‭amylase,‬‭mucin,‬‭buffers,‬‭and‬ ‭anti-bacterial‬‭agents.‬ ‭Salivary‬‭amylase‬‭digests‬‭starch‬‭into‬‭maltose.‬‭The‬‭optimum‬‭pH‬‭for‬‭this‬‭is‬‭7.‬ ‭Oesophagus‬ ‭ he‬‭bolus‬‭is‬‭pushed‬‭along‬‭the‬‭oesophagus‬‭by‬‭peristalsis,‬‭not‬‭gravity.‬‭There‬‭are‬‭rhythmic‬‭waves‬ T ‭of‬‭contraction‬‭by‬‭smooth‬‭muscles‬‭in‬‭the‬‭walls‬‭of‬‭the‬‭alimentary‬‭canal.‬ ‭Stomach‬ ‭ astric‬‭glands‬‭in‬‭the‬‭stomach‬‭secretes‬‭gastric‬‭juice.‬‭It‬‭mixes‬‭this‬‭with‬‭the‬‭food‬‭using‬‭the‬ G ‭churning‬‭action‬‭of‬‭the‬‭smooth‬‭muscles‬‭in‬‭the‬‭stomach‬‭wall.‬‭Hydrochloric‬‭acid‬‭in‬‭gastric‬‭juice‬‭has‬ ‭a‬‭pH‬‭of‬‭2,‬‭which‬‭kills‬‭bacteria‬‭and‬‭denatures‬‭proteins‬‭in‬‭the‬‭food.‬‭Pepsin‬‭works‬‭well‬‭in‬‭strongly‬ ‭acidic‬‭environments.‬‭It‬‭breaks‬‭peptide‬‭bonds‬‭in‬‭proteins‬‭which‬‭produces‬‭smaller‬‭polypeptides.‬ ‭ Cl‬‭and‬‭pepsin‬‭are‬‭released‬‭directly‬‭into‬‭the‬‭lumen‬‭of‬‭the‬‭stomach‬‭so‬‭the‬‭cells‬‭of‬‭the‬‭stomach‬ H ‭are‬‭protected‬‭from‬‭self-digestion.‬‭The‬‭stomach‬‭lining‬‭is‬‭further‬‭protecting‬‭by‬‭a‬‭coating‬‭of‬‭mucus‬ ‭which‬‭is‬‭secreted‬‭by‬‭the‬‭epithelial‬‭cells.‬‭However,‬‭the‬‭epithelium‬‭is‬‭continuously‬‭eroded,‬‭and‬ ‭are‬‭replaced‬‭regularly‬‭by‬‭mitosis.‬ ‭Intestinal‬‭juice‬‭contains‬‭peptidase,‬‭maltase,‬‭sucrase‬‭(invertase),‬‭lactase,‬‭and‬‭lipase.‬ ‭Peristalsis‬ I‭n‬‭peristalsis‬‭(especially‬‭in‬‭the‬‭oesophagus),‬‭the‬‭two‬‭sets‬‭of‬‭muscles‬‭are‬‭longitudinal‬‭and‬ ‭circular‬‭muscles,‬‭which‬‭work‬‭antagonistically.‬‭When‬‭one‬‭contracts,‬‭the‬‭other‬‭relaxes.‬‭The‬‭food‬ ‭is‬‭squeezed‬‭and‬‭pushed‬‭forward.‬ !‭‬‭https://prod-files-secure.s3.us-west-2.amazonaws.com/94a250b5-19bc-4880-9eb3-ccfe47b69b‬ ‭88/df0f75eb-e04b-446c-9d0c-f233a7f96b88/image1.png‬ ‭Absorption‬ ‭ mino‬‭acids‬‭and‬‭glucose‬‭are‬‭absorbed‬‭in‬‭the‬‭blood‬‭capillaries‬‭of‬‭the‬‭villi‬‭by‬‭diffusion‬‭down‬‭the‬ A ‭concentration‬‭gradients,‬‭and‬‭active‬‭transport‬‭against‬‭the‬‭concentration‬‭gradient.‬‭Capillaries‬ ‭converge‬‭into‬‭the‬‭hepatic‬‭portal‬‭vein‬‭which‬‭goes‬‭to‬‭the‬‭liver.‬ !‭‬‭https://prod-files-secure.s3.us-west-2.amazonaws.com/94a250b5-19bc-4880-9eb3-ccfe47b69b‬ ‭88/e7faa236-e4c9-4392-b3cf-3ac4a3428e9a/image4.png‬ ‭Unknown‬‭Content‬‭-‬‭Biology‬‭WA2‬ ‭Enzymes‬ ‭ atabolic‬‭pathways‬‭-‬‭Releases‬‭energy‬‭by‬‭breaking‬‭complex‬‭molecules‬‭into‬‭simpler‬ C ‭compounds.‬ ‭Anabolic‬‭pathways‬‭-‬‭Uses‬‭energy‬‭to‬‭build‬‭larger‬‭complex‬‭molecules‬‭from‬‭smaller‬‭simpler‬‭ones.‬ ‭ nzyme‬‭-‬‭Biological‬‭catalysts‬‭that‬‭alter‬‭the‬‭rate‬‭of‬‭chemical‬‭reactions‬‭without‬‭being‬ E ‭chemically‬‭changed‬‭at‬‭the‬‭end‬‭of‬‭a‬‭reaction.‬ ‭Enzymes‬‭lower‬‭the‬‭activation‬‭energy‬‭required‬‭for‬‭reactions.‬ ‭ ctivation‬‭energy‬‭is‬‭the‬‭amount‬‭of‬‭energy‬‭required‬‭to‬‭bring‬‭a‬‭molecule‬‭from‬‭its‬‭reactants‬‭to‬‭its‬ A ‭transition‬‭state.‬ !‭‬‭https://prod-files-secure.s3.us-west-2.amazonaws.com/94a250b5-19bc-4880-9eb3-ccfe47b69b‬ ‭88/39d5e997-2328-4d2d-b06f-f367e8a78ddb/image21.png‬ ‭ nzymes‬‭are‬‭required‬‭to‬‭lower‬‭the‬‭activation‬‭energy‬‭required‬‭for‬‭reactions‬‭because‬‭heating‬‭to‬ E ‭do‬‭so‬‭would‬‭denature‬‭proteins‬‭and‬‭is‬‭not‬‭suitable‬‭for‬‭organisms.‬ ‭ ock‬‭and‬‭key‬‭hypothesis:‬‭Reaction‬‭catalysed‬‭by‬‭each‬‭enzyme‬‭is‬‭very‬‭specific‬‭.‬‭The‬‭enzyme‬ L ‭will‬‭bind‬‭to‬‭a‬‭substrate‬‭with‬‭a‬‭complementary‬‭shape‬‭which‬‭fits‬‭into‬‭the‬‭active‬‭site‬‭of‬‭the‬‭enzyme‬ ‭to‬‭form‬‭an‬‭enzyme-substrate‬‭complex‬‭.‬‭While‬‭bound,‬‭the‬‭catalytic‬‭action‬‭of‬‭the‬‭enzyme‬ ‭converts‬‭the‬‭substrate‬‭into‬‭the‬‭products‬‭.‬ ‭Reason‬‭of‬‭specificity‬‭-‬‭Three-dimensional‬‭shape,‬‭consequence‬‭of‬‭amino‬‭acid‬‭sequence‬ ‭ nzyme‬‭activity‬‭can‬‭be‬‭investigated‬‭either‬‭by‬‭measuring‬‭the‬‭formation‬‭of‬‭products‬‭or‬‭the‬ E ‭disappearance‬‭of‬‭substrates.‬ ‭Nutrition‬‭in‬‭humans‬ ‭Ingestion‬‭>‬‭Digestion‬‭>‬‭Absorption‬‭>‬‭Assimilation‬‭>‬‭Egestion‬ ‭ outh‬‭-‬‭Physical‬‭and‬‭chemical‬‭digestion‬‭occur‬‭in‬‭the‬‭buccal‬‭cavity‬‭.‬‭Presence‬‭of‬‭food‬‭triggers‬‭a‬ M ‭nervous‬‭reflex‬‭which‬‭secretes‬‭saliva‬‭through‬‭salivary‬‭ducts‬‭to‬‭the‬‭buccal‬‭cavity.‬ ‭ wallowing‬‭-‬‭Tongue‬‭rolls‬‭food‬‭into‬‭a‬‭bolus‬‭,‬‭and‬‭pushes‬‭it‬‭into‬‭the‬‭buccal‬‭cavity‬‭and‬‭pharynx‬‭.‬ S ‭Glottis‬‭(trachea‬‭opening)‬‭is‬‭blocked‬‭by‬‭epiglottis‬‭flap.‬ ‭Small‬‭intestine‬‭parts‬‭-‬‭Duodenum‬‭>‬‭Ileum‬‭>‬‭Jejunum‬ ‭ uodenum‬‭-‬‭Secretes‬‭intestinal‬‭juice‬‭into‬‭lumen‬‭containing‬‭peptidase‬‭,‬‭maltase‬‭,‬‭sucrase‬‭,‬ D ‭lactase‬‭,‬‭lipase‬‭.‬‭Most‬‭digestion‬‭is‬‭completed‬‭here.‬ ‭Ileum‬‭-‬‭Absorption‬‭of‬‭digested‬‭food‬ ‭Jejunum‬‭-‬‭Absorption‬‭of‬‭digested‬‭food‬ ‭ bsorption‬‭details‬‭-‬‭Amino‬‭acids‬‭and‬‭glucose‬‭are‬‭absorbed‬‭into‬‭blood‬‭capillaries‬‭by‬‭diffusion‬ A ‭and‬‭active‬‭transport.‬‭Capillaries‬‭converge‬‭into‬‭larger‬‭blood‬‭vessels‬‭and‬‭then‬‭the‬‭hepatic‬‭portal‬ ‭vein‬‭leading‬‭to‬‭the‬‭liver.‬ ‭‬ G ‭ lycerol‬‭and‬‭fatty‬‭acids‬‭are‬‭absorbed‬‭by‬‭diffusion‬‭only‬‭into‬‭the‬‭epithelial‬‭cells‬‭and‬ ‭recombined‬‭into‬‭fat‬‭molecules,‬‭then‬‭mixed‬‭with‬‭cholesterol‬‭and‬‭special‬‭proteins‬‭to‬‭form‬ ‭chylomicrons,‬‭then‬‭transported‬‭into‬‭lacteals‬‭of‬‭each‬‭villus.‬ ‭ mall‬‭intestine‬‭is‬‭adapted‬‭for‬‭absorption‬‭with‬‭a‬‭large‬‭surface‬‭area,‬‭net‬‭of‬‭blood‬‭capillaries‬‭and‬ S ‭lacteals‬‭causing‬‭a‬‭steep‬‭concentration‬‭gradient‬‭,‬‭one-cell‬‭thick‬‭epithelium,‬‭and‬‭many‬ ‭mitochondria‬‭in‬‭epithelial‬‭cells‬‭to‬‭facilitate‬‭active‬‭transport.‬ ‭Pancreas‬‭-‬‭Produces‬‭alkaline‬‭pancreatic‬‭juice‬‭containing‬‭trypsin‬‭(protease),‬‭amylase‬‭,‬‭lipase‬‭.‬ ‭Liver‬ ‭ ‬‭-‬‭Secretes‬‭insulin‬‭to‬‭stimulate‬‭conversion‬‭of‬‭excess‬‭glucose‬‭to‬‭glycogen‬‭if‬‭blood‬ 1 ‭concentration‬‭is‬‭high‬ ‭ ecretes‬‭glucagon‬‭to‬‭stimulate‬‭conversion‬‭of‬‭excess‬‭glycogen‬‭to‬‭glucose‬‭if‬‭blood‬ S ‭concentration‬‭is‬‭low‬ ‭Blood‬‭glucose‬‭concentration‬‭=‬‭90mg/100ml‬‭=‬‭0.9‬‭g/dm3‬ ‭2‬‭-‬‭Secretes‬‭bile‬‭that‬‭is‬‭stored‬‭in‬‭the‬‭gall‬‭bladder.‬ ‭3‬‭-‬‭Breaks‬‭down‬‭hormones‬‭after‬‭use‬ ‭ ‬‭-‬‭Metabolises‬‭excess‬‭amino‬‭acids‬‭by‬‭deamination‬‭to‬‭eventually‬‭be‬‭converted‬‭into‬‭urea‬‭and‬ 4 ‭glycogen.‬ ‭5‬‭-‬‭Breaks‬‭down‬‭alcohol‬‭by‬‭oxidation‬‭to‬‭acetaldehyde‬ ‭Self-test.‬‭Bolded‬‭are‬‭unknown‬ ‭5‬‭functions‬‭of‬‭the‬‭liver?‬ ‭.‬ 1 ‭ lood‬‭glucose‬‭concentration‬‭regulation‬ B ‭2.‬ ‭Hormone‬‭removal‬ ‭3.‬ ‭Production‬‭of‬‭bile‬‭for‬‭digestion‬ ‭4.‬ ‭Oxidation‬‭of‬‭alcohol‬ ‭5.‬ ‭Deamination‬‭of‬‭excess‬‭amino‬‭acids‬ ‭How‬‭can‬‭you‬‭measure‬‭the‬‭rate‬‭of‬‭enzyme‬‭activity‬‭with‬‭an‬‭experiment?‬‭There‬‭are‬‭two‬‭ways.‬ ‭How‬‭are‬‭amino‬‭acids‬‭and‬‭glucose‬‭and‬‭fat‬‭molecules‬‭absorbed‬‭in‬‭the‬‭small‬‭intestine?‬ ‭Transport‬ ‭‬ ‭Consists‬‭of‬‭blood‬‭and‬‭lymphatic‬‭system‬ ‭‬ ‭Double‬‭circulation,‬‭pulmonary‬‭and‬‭systemic‬ ‭‬ ‭Lymphatic‬‭system‬‭is‬‭one-way‬‭from‬‭interstitial‬‭fluid‬‭to‬‭cardiovascular‬‭system‬ ‭‬ B ‭ lood‬‭consists‬‭of‬‭blood‬‭plasma‬‭(55%),‬‭red‬‭blood‬‭cells‬‭,‬‭white‬‭blood‬‭cells‬‭,‬‭and‬ ‭platelets‬‭.‬ ‭‬ B ‭ lood‬‭plasma‬‭contains‬‭inorganic‬‭ions/salts,‬‭plasma‬‭proteins,‬‭organic‬‭nutrients,‬ ‭nitrogenous‬‭wastes,‬‭hormones,‬‭dissolved‬‭gases‬ ‭‬ ‭Red‬‭blood‬‭cells‬‭(erythrocytes)‬‭produced‬‭by‬‭bone‬‭marrow,‬‭contains‬‭haemoglobin‬ ‭‬ P ‭ rotein‬‭molecule‬‭haemoglobin‬‭consists‬‭of‬‭four‬‭subunits,‬‭which‬‭each‬‭consist‬‭of‬‭globular‬ ‭proteins‬‭attached‬‭to‬‭haem‬‭unit‬‭(which‬‭then‬‭comprises‬‭of‬‭porphyrin‬‭ring‬‭containing‬‭iron‬ ‭atom)‬ ‭‬ A ‭ daptations‬‭of‬‭erythrocytes:‬‭Biconcave‬‭circular,‬‭haemoglobin,‬‭no‬‭nucleus,‬‭flexible‬ ‭plasma‬‭membrane,‬‭small‬‭size‬ ‭‬ ‭No‬‭nucleus‬‭allows‬‭red‬‭blood‬‭cell‬‭to‬‭carry‬‭more‬‭haemoglobin‬‭(not‬‭oxygen)‬ ‭‬ ‭Acclimatisation‬ ‭‬ ‭White‬‭blood‬‭cells‬‭(leucocytes)‬‭have‬‭two‬‭types‬‭lymphocytes‬‭and‬‭phagocytes‬ ‭‬ L ‭ ymphocytes‬‭-‬‭Large‬‭rounded‬‭nucleus,‬‭limited‬‭movement,‬‭doesn’t‬‭squeeze‬‭through‬ ‭capillary‬‭walls,‬‭produces‬‭antibodies‬‭in‬‭response‬‭to‬‭foreign‬‭proteins‬‭antigens‬‭from‬ ‭pathogens.‬ ‭‬ ‭Antibodies‬‭does‬‭the‬‭following:‬ ‭Cause‬‭bacteria‬‭to‬‭agglutinate‬‭to‬‭facilitate‬‭phagocytosis/ingestion‬‭by‬‭phagocytes‬ ‭Neutralises‬‭toxins‬‭from‬‭bacteria‬ ‭Ruptures‬‭bacteria‬‭cell‬‭membrane‬ ‭‬ P ‭ hagocytes‬‭-‬‭bean‬‭shaped,‬‭capable‬‭of‬‭amoeboid‬‭movement‬‭and‬‭through‬‭capillary‬‭walls‬ ‭to‬‭infected‬‭areas,‬‭shorter‬‭lifespan‬‭than‬‭lymphocytes‬ ‭‬ U ‭ ndergoes‬‭phagocytosis‬‭to‬‭ingest‬‭foreign‬‭particles,‬‭engulfs‬‭it‬‭to‬‭form‬‭vesicle,‬‭fused‬‭with‬ ‭lysosome‬‭containing‬‭hydrolytic‬‭enzymes‬‭to‬‭digest‬‭the‬‭bacteria‬ ‭‬ B ‭ lood‬‭platelets‬‭(thrombocytes)‬‭initiate‬‭blood‬‭clotting‬‭to‬‭prevent‬‭excessive‬‭loss‬‭of‬‭blood‬ ‭and‬‭entry‬‭of‬‭harmful‬‭bacteria‬ ‭‬ P ‭ latelets‬‭release‬‭enzyme‬‭thrombin‬‭,‬‭catalyses‬‭conversion‬‭of‬‭soluble‬‭protein‬‭fibrinogen‬ ‭to‬‭insoluble‬‭fibrin‬‭threads‬ ‭‬ ‭Fibrin‬‭threads‬‭entangle‬‭blood‬‭cells,‬‭whole‬‭mass‬‭forms‬‭a‬‭clot‬‭or‬‭scab‬ ‭‬ ‭Blood‬‭group‬‭number‬‭represents‬‭the‬‭antigens‬‭it‬‭has‬‭.‬‭(Group‬‭O‬‭means‬‭no‬‭antigens)‬ ‭‬ ‭Antigens‬‭and‬‭antibodies‬‭of‬‭the‬‭same‬‭type‬‭agglutinates‬‭(A‬‭agglutinates‬‭with‬‭a)‬ ‭‬ ‭Antigens‬‭marked‬‭with‬‭capital‬‭letters,‬‭antibodies‬‭marked‬‭with‬‭small‬‭letters‬ ‭‬ ‭AB‬‭is‬‭the‬‭universal‬‭acceptor,‬‭O‬‭is‬‭the‬‭universal‬‭donor‬ ‭‬ ‭Tissue‬‭rejection‬‭occurs‬‭when‬‭transplanted‬‭organ‬‭is‬‭not‬‭compatible‬‭with‬‭patient’s‬‭original‬ ‭‬ ‭General‬‭blood‬‭flow:‬‭Artery‬‭-‬‭Arteriole‬‭-‬‭Capillary‬‭-‬‭Venule‬‭-‬‭Vein‬ ‭‬ A ‭ rteries‬‭has‬‭thick‬‭muscular,‬‭and‬‭elastic‬‭walls‬‭;‬‭and‬‭a‬‭smaller‬‭lumen‬‭than‬‭veins;‬‭blood‬ ‭flows‬‭under‬‭high‬‭pressure‬‭in‬‭pulses‬ ‭‬ ‭Thick‬‭muscular‬‭walls‬‭constricts‬‭and‬‭dilates‬‭arteries‬‭to‬‭maintain‬‭pressure‬ ‭‬ ‭Elastic‬‭walls‬‭withstands‬‭high‬‭pressure‬‭by‬‭ventricular‬‭contractions‬‭of‬‭heart‬ ‭‬ V ‭ eins‬‭have‬‭less‬‭muscular‬‭and‬‭elastic‬‭walls,‬‭larger‬‭lumen‬‭than‬‭arteries,‬‭presence‬‭of‬ ‭semi-lunar‬‭valves.‬‭Blood‬‭flows‬‭under‬‭lower‬‭pressure‬ ‭‬ ‭Semi-lunar‬‭valves‬‭prevent‬‭backflow‬‭of‬‭blood‬‭when‬‭closed‬ ‭‬ ‭Capillaries‬‭are‬‭microscopic‬‭blood‬‭vessels,‬‭walls‬‭are‬‭single‬‭layer‬‭of‬‭cells‬‭(endothelium)‬ ‭‬ P ‭ artially‬‭permeable‬‭or‬‭one-cell‬‭thick‬‭endothelium‬‭enables‬‭quick‬‭diffusion‬‭of‬‭smaller‬ ‭substances‬ ‭‬ H ‭ ighly‬‭branched‬‭network‬‭of‬‭capillaries‬‭provides‬‭large‬‭surface‬‭area‬‭for‬‭exchange‬‭of‬ ‭substances,‬‭reduces‬‭blood‬‭pressure‬‭to‬‭slow‬‭down‬‭blood‬‭flow‬‭for‬‭exchange‬‭of‬ ‭substances‬ ‭‬ ‭Plasma‬‭forced‬‭out‬‭of‬‭arterial‬‭end‬‭of‬‭capillary‬‭to‬‭form‬‭tissue‬‭fluid‬ ‭‬ ‭Tissue‬‭fluid‬‭is‬‭a‬‭medium‬‭for‬‭transfer‬‭of‬‭substances‬‭between‬‭capillaries‬‭and‬‭cell‬ ‭‬ ‭Dissolved‬‭food‬‭and‬‭oxygen‬‭diffuses‬‭from‬‭capillaries‬‭into‬‭tissue‬‭fluid‬‭then‬‭into‬‭cells‬ ‭‬ ‭Waste‬‭products‬‭go‬‭the‬‭other‬‭way‬ ‭‬ T ‭ issue‬‭fluid‬‭returns‬‭to‬‭circulatory‬‭system‬‭by‬‭venous‬‭end‬‭of‬‭capillary‬‭network‬‭and‬ ‭lymphatic‬‭capillaries‬ ‭‬ S ‭ welling‬‭of‬‭organs‬‭and‬‭tissues‬‭occurs‬‭when‬‭accumulated‬‭tissue‬‭fluid‬‭is‬‭not‬‭returned‬‭to‬ ‭blood‬ ‭‬ ‭Advantages‬‭of‬‭double‬‭circulation:‬ ‭Blood‬‭enters‬‭lungs‬‭at‬‭lower‬‭pressure,‬‭sufficient‬‭time‬‭for‬‭blood‬‭to‬‭be‬‭oxygenated‬‭well‬ ‭Blood‬‭pumped‬‭to‬‭body‬‭tissues‬‭at‬‭higher‬‭pressure‬‭by‬‭heart,‬‭distributes‬‭oxygen‬‭to‬‭them‬ f‭aster‬ ‭‬ H ‭ eart‬‭has‬‭2‬‭upper‬‭chambers‬‭atria‬‭and‬‭2‬‭larger‬‭lower‬‭chambers‬‭ventricles‬‭;‬‭right‬‭side‬ ‭completely‬‭separated‬‭from‬‭left‬‭by‬‭septum‬‭to‬‭prevent‬‭mixing‬‭of‬‭oxygenated‬‭and‬ ‭deoxygenated‬‭blood‬ ‭‬ A ‭ tria‬‭has‬‭thinner‬‭walls‬‭than‬‭ventricles‬‭because‬‭distance‬‭between‬‭atria‬‭and‬‭ventricles‬‭are‬ ‭short‬ ‭‬ L ‭ eft‬‭ventricle‬‭has‬‭thicker‬‭walls‬‭than‬‭right‬‭ventricle‬‭because‬‭systemic‬‭vs‬‭pulmonary‬ ‭circulation‬ ‭‬ P ‭ ath:‬‭Vena‬‭cava‬‭-‬‭Right‬‭atria‬‭-‬‭Right‬‭ventricle‬‭-‬‭Pulmonary‬‭artery‬‭-‬‭Lungs‬‭-‬‭Pulmonary‬ ‭vein‬‭-‬‭Left‬‭atria‬‭-‬‭Left‬‭ventricle‬‭-‬‭Aorta‬‭-‬‭Body‬ ‭‬ D ‭ iastole‬‭(0.4s)‬‭:‬‭All‬‭muscles‬‭relaxed,‬‭blood‬‭flows‬‭into‬‭the‬‭heart,‬‭oxygenated‬‭blood‬ ‭enters‬‭left‬‭atrium,‬‭deoxygenated‬‭blood‬‭enters‬‭right‬‭atrium,‬‭blood‬‭flows‬‭passively‬‭into‬ ‭ventricles‬‭when‬‭bicuspid‬‭and‬‭tricuspid‬‭valve‬‭are‬‭open‬ ‭‬ A ‭ trial‬‭Systole‬‭(0.15s)‬‭:‬‭Muscles‬‭of‬‭atria‬‭contract,‬‭muscles‬‭of‬‭ventricles‬‭remain‬‭relaxed,‬ ‭blood‬‭pumped‬‭from‬‭ventricles‬‭to‬‭atria,‬‭aortic‬‭and‬‭pulmonary‬‭valves‬‭remain‬‭closed‬ ‭‬ V ‭ entricular‬‭Systole‬‭(0.3s)‬‭:‬‭Muscles‬‭of‬‭ventricles‬‭contract,‬‭muscles‬‭of‬‭atria‬‭begin‬‭to‬ ‭relax‬‭,‬‭steep‬‭increase‬‭of‬‭pressure‬‭closes‬‭bicuspid‬‭and‬‭tricuspid‬‭valves‬‭forcefully‬ ‭causing‬‭“Lub”,‬‭aortic‬‭and‬‭pulmonary‬‭valves‬‭forced‬‭open,‬‭blood‬‭forced‬‭into‬‭respective‬ ‭vessels‬‭(aorta‬‭and‬‭pulmonary‬‭artery)‬ ‭‬ V ‭ entricular‬‭Diastole‬‭:‬‭Ventricles‬‭start‬‭to‬‭relax,‬‭pressure‬‭falls,‬‭high‬‭pressure‬‭from‬‭aorta‬ ‭and‬‭pulmonary‬‭arteries‬‭causes‬‭blood‬‭to‬‭flow‬‭back‬‭towards‬‭ventricles,‬‭closes‬‭aortic‬‭and‬ ‭pulmonary‬‭valves,‬‭prevents‬‭backflow‬‭of‬‭blood,‬‭causes‬‭“Dub”.‬  ‭‬ A ‭ ccumulation‬‭of‬‭cholesterol‬‭and‬‭polysaturated‬‭fats‬‭are‬‭deposited‬‭on‬‭inner‬‭wall‬‭of‬ ‭coronary‬‭arteries‬‭during‬‭atherosclerosis,‬‭lumen‬‭narrows,‬‭blood‬‭pressure‬‭increases‬ ‭Respiration‬ ‭‬ R ‭ espiration‬‭occurs‬‭in‬‭mitochondria‬‭of‬‭all‬‭living‬‭cells.‬‭Each‬‭step‬‭is‬‭controlled‬‭by‬‭enzymes.‬ ‭‬ ‭Breakdown‬‭of‬‭food‬‭substances‬‭through‬‭oxidation‬‭in‬‭living‬‭cells‬‭with‬‭the‬‭release‬‭of‬ ‭energy‬‭.‬ ‭‬ ‭Point‬‭of‬‭rate‬‭of‬‭photosynthesis‬‭being‬‭equal‬‭to‬‭rate‬‭of‬‭respiration‬‭in‬‭plants‬‭is‬ ➡️ ‭compensation‬‭point.‬ ‭‬ ‭Aerobic‬‭respiration:‬‭C6H12O6‬‭+‬‭6O2‬‭ ‬‭6CO2‬‭+‬‭6H2O‬‭|‬‭Large‬‭amount‬‭of‬‭energy‬ ➡️ ‭released‬ ‭‬ ‭Anaerobic‬‭respiration:‬‭C6H12O6‬‭ 2CO2‬‭+‬‭2C2H5OH‬‭|‬‭Relatively‬‭small‬‭amt.‬‭of‬‭energy‬ ➡️ ‭released,‬‭ethanol‬‭on‬‭right,‬‭anaerobic‬‭respiration‬‭in‬‭yeast‬ ‭‬ ‭Anaerobic‬‭respiration:‬‭C6H12O6‬‭ 2‬‭C3H6O3‬‭|‬‭Relatively‬‭small‬‭amt.‬‭of‬‭energy‬ ‭released,‬‭lactic‬‭acid,‬‭anaerobic‬‭respiration‬‭in‬‭humans‬ ‭‬ ‭Total‬‭energy‬‭needed‬‭=‬‭Aerobic‬‭respiration‬‭energy‬‭+‬‭Anaerobic‬‭respiration‬‭energy‬ ‭‬ ‭Oxygen‬‭debt‬‭is‬‭the‬‭amount‬‭of‬‭oxygen‬‭needed‬‭to‬‭break‬‭down‬‭all‬‭lactic‬‭acid‬‭accumulated‬ ‭in‬‭muscles‬‭during‬‭anaerobic‬‭respiration.‬ ‭‬ ‭Oxygen‬‭debt‬‭is‬‭incurred‬‭due‬‭to‬‭insufficient‬‭oxygen‬‭to‬‭meet‬‭demands‬‭of‬‭muscular‬ ‭contraction‬ ‭‬ ‭Lactic‬‭acid‬‭is‬‭removed‬‭from‬‭muscles‬‭and‬‭transported‬‭to‬‭liver,‬‭some‬‭is‬‭oxidised‬‭to‬‭release‬ ‭energy‬‭to‬‭convert‬‭remaining‬‭lactic‬‭acid‬‭into‬‭glucose‬‭then‬‭glycogen‬‭as‬‭storage.‬ ‭‬ ‭Passage‬‭of‬‭air:‬‭Mouth/Nostrils‬‭-‬‭Pharynx‬‭-‬‭Larynx‬‭-‬‭Trachea‬‭-‬‭Bronchi‬‭-‬‭Bronchioles‬‭-‬ ‭Alveoli‬ ‭‬ ‭Hairs‬‭and‬‭mucous‬‭membrane‬‭trap‬‭dust‬‭and‬‭bacteria‬‭in‬‭air‬‭in‬‭nostrils‬ ‭‬ ‭Sensory‬‭cells‬‭in‬‭mucous‬‭membrane‬‭detect‬‭harmful‬‭chemicals‬ ‭‬ ‭Gland‬‭cells‬‭in‬‭trachea‬‭secrete‬‭mucus‬‭to‬‭trap‬‭dust‬‭and‬‭bacteria‬ ‭‬ ‭Ciliated‬‭cells‬‭bear‬‭cilia‬‭to‬‭sweep‬‭trapped‬‭dust‬‭and‬‭bacteria‬‭upwards‬‭into‬‭the‬‭pharynx,‬ ‭then‬‭swallowed‬‭into‬‭the‬‭oesophagus.‬‭(SHITE‬‭i‬‭have‬‭phlegm‬‭now)‬ ‭‬ ‭Thin‬‭layer‬‭of‬‭lubricating‬‭fluid‬‭allows‬‭pleura‬‭(a‬‭membrane)‬‭to‬‭glide‬‭over‬‭one‬‭another‬‭easily‬ ‭when‬‭lungs‬‭contract‬‭or‬‭expand‬‭during‬‭breathing.‬ ‭‬ ‭Total‬‭volume‬‭of‬‭air‬‭in‬‭lungs‬‭consists‬‭of‬‭Inspiratory‬‭reserve‬‭volume‬‭(max‬‭inhale‬‭limit),‬ ‭Tidal‬‭volume‬‭(regular‬‭breathing‬‭limit),‬‭Expiratory‬‭reserve‬‭volume‬‭(max‬‭exhale‬‭limit),‬ ‭Residual‬‭volume‬‭(air‬‭that‬‭cannot‬‭be‬‭exhaled).‬ ‭‬ ‭Oxygen‬‭dissolves‬‭in‬‭moisture‬‭lining‬‭alveolar‬‭walls,‬‭diffuses‬‭through‬‭alveolar‬‭walls‬‭into‬ ‭blood‬‭capillaries.‬ ‭‬ ‭Oxygen‬‭enters‬‭blood‬‭plasma,‬‭combines‬‭chemically‬‭with‬‭haemoglobin‬‭to‬‭form‬ ‭oxyhaemoglobin‬ ‭‬ ‭Alveoli‬‭contain‬‭collagen‬‭and‬‭elastic‬‭fibers‬‭that‬‭allow‬‭alveoli‬‭to‬‭stretch‬‭during‬‭inhalation‬‭to‬ ‭fill‬‭it‬‭with‬‭air‬ ‭‬ ‭Concentration‬‭gradient‬‭of‬‭gases‬‭is‬‭maintained‬‭by‬‭continuous‬‭flow‬‭of‬‭blood‬‭and‬ ‭constant‬‭breathing‬‭of‬‭air.‬ ‭‬ ‭Alveoli‬‭adaptations‬‭include‬‭(below)‬  ‭‬ ‭ umerous‬‭alveoli,‬‭large‬‭surface‬‭area‬ N ‭‬ ‭One-cell‬‭thick‬‭alveoli,‬‭short‬‭diffusion‬‭distance‬ ‭‬ ‭Thin‬‭film‬‭of‬‭moisture‬‭on‬‭surface‬‭of‬‭alveolus,‬‭allows‬‭oxygen‬‭to‬‭dissolve‬ ‭‬ ‭Continuous‬‭blood‬‭flow,‬‭maintains‬‭concentration‬‭gradient‬ ‭‬ ‭In‬‭INHALATION:‬‭(To‬‭remember‬‭antagonstic‬‭motion,‬‭respective‬‭muscle‬‭relaxes‬‭-‬‭External‬ ‭relaxes‬‭upon‬‭expiration)‬ ‭‬ ‭External‬‭intercostal‬‭muscles‬‭contract‬‭,‬‭shorten‬ ‭‬ ‭Internal‬‭intercostal‬‭muscles‬‭relax‬‭,‬‭lengthen‬ ‭‬ ‭Ribs‬‭and‬‭sternum‬‭move‬‭upwards‬‭and‬‭outwards‬ ‭‬ ‭Diaphragm‬‭contracts‬‭and‬‭flattens‬ ‭‬ ‭Volume‬‭of‬‭lungs‬‭increases,‬‭pressure‬‭decreases‬ ‭‬ ‭In‬‭EXHALATION:‬ ‭‬ ‭External‬‭intercostal‬‭muscles‬‭relax‬‭,‬‭lengthen‬ ‭‬ ‭Internal‬‭intercostal‬‭muscles‬‭contract‬‭,‬‭shorten‬ ‭‬ ‭Ribs‬‭and‬‭sternum‬‭move‬‭downwards‬‭and‬‭inwards‬ ‭‬ ‭Diaphragm‬‭relaxes‬‭and‬‭arches‬‭outwards‬ ‭‬ ‭Volume‬‭of‬‭lungs‬‭decreases,‬‭pressure‬‭increases‬ ‭‬ ‭Atmospheric‬‭pressure‬‭is‬‭higher/lower‬‭than‬‭pressure‬‭in‬‭lungs,‬‭air‬‭passively‬‭flows‬‭in/out‬‭of‬ ‭lungs‬ ‭‬ ‭Breathing‬‭stimulus‬‭is‬‭the‬‭accumulation‬‭of‬‭carbon‬‭dioxide‬‭causing‬‭a‬‭lower‬‭pH.‬ ‭‬ ‭Lack‬‭of‬‭oxygen‬‭is‬‭not‬‭a‬‭breathing‬‭stimulus‬ ‭‬ ‭Nicotine‬‭-‬‭addictive‬‭,‬‭increases‬‭heart‬‭rate,‬‭blood‬‭pressure,‬‭and‬‭blood‬‭clots‬‭in‬‭blood‬ ‭vessels‬ ‭‬ ‭Carbon‬‭monoxide‬‭-‬‭deadly‬‭,‬‭combines‬‭irreversibly‬‭with‬‭haemoglobin‬‭to‬‭form‬ ‭carboxyhaemoglobin,‬‭reduces‬‭amount‬‭of‬‭haemoglobin‬‭in‬‭blood,‬‭increases‬‭blood‬‭clots‬‭in‬ ‭blood‬‭vessels‬ ‭‬ ‭Tar‬‭-‬‭cancerous‬‭,‬‭blocks‬‭air‬‭sacs,‬‭paralyses‬‭cillia‬‭lining‬‭air‬‭passage,‬‭prevents‬‭removal‬‭of‬ ‭mucus‬ ‭.‬ 1 ‭Define‬‭oxygen‬‭debt‬ ‭2.‬ ‭How‬‭is‬‭oxygen‬‭debt‬‭managed‬ ‭3.‬ ‭State‬‭the‬‭passage‬‭of‬‭air‬‭into‬‭the‬‭respiratory‬‭system‬ ‭4.‬ ‭State‬‭the‬‭passage‬‭of‬‭oxygen‬‭into‬‭the‬‭bloodstream‬ ‭5.‬ ‭State‬‭the‬‭adaptations‬‭of‬‭the‬‭nose‬‭and‬‭trachea‬‭to‬‭remove‬‭bacteria‬‭or‬‭dust.‬ ‭6.‬ ‭List‬‭the‬‭action‬‭of‬‭intercostal‬‭muscles,‬‭ribs‬‭and‬‭sternum,‬‭and‬‭diaphragm‬‭in‬‭inspiration‬‭and‬ ‭expiration‬‭as‬‭well‬‭as‬‭volume‬‭and‬‭pressure‬‭of‬‭lungs.‬ ‭.‬ 7 ‭State‬‭the‬‭action‬‭of‬‭breathing‬ ‭8.‬ ‭State‬‭why‬‭smoking‬‭bad‬ ‭Excretion‬ ‭‬ M ‭ etabolic‬‭waste‬‭products‬‭and‬‭toxins‬‭are‬‭removed‬‭in‬‭excretion‬ ‭‬ ‭Includes‬‭urea,‬‭carbo=n‬‭dioxide,‬‭bile‬‭pigments,‬‭water,‬‭oxygen‬‭(in‬‭photosynthesis)‬ ‭‬ ‭Prevents‬‭accumulation‬‭of‬‭metabolic‬‭waste,‬‭which‬‭can‬‭alter‬‭pH/water‬‭potential‬‭of‬‭body‬ ‭fluids‬‭or‬‭poison‬‭enzyme‬‭systems‬ ‭‬ ‭Carbon‬‭dioxide‬‭excreted‬‭as‬‭gas‬‭in‬‭exhaled‬‭air‬  ‭‬ M ‭ ineral‬‭salts,‬‭nitrogenous‬‭waste‬‭products‬‭(urea,‬‭uric‬‭acid)‬‭and‬‭creatinine‬‭(from‬‭muscle‬ ‭tissue‬‭breakdown)‬‭excreted‬‭as‬‭urine‬‭and‬‭sweat‬‭(in‬‭smaller‬‭quantities)‬ ‭‬ ‭Excess‬‭water‬‭excreted‬‭as‬‭main‬‭constituent‬‭of‬‭urine‬‭and‬‭sweat‬‭and‬‭as‬‭vapour‬‭in‬‭exhaled‬ ‭air‬ ‭‬ ‭Bile‬‭pigments‬‭excreted‬‭as‬‭constituent‬‭of‬‭faeces‬‭through‬‭intestines‬ ‭‬ ‭Excretion‬‭is‬‭the‬‭removal‬‭of‬‭metabolic‬‭waste‬‭products‬ ‭‬ ‭Egestion‬‭is‬‭the‬‭removal‬‭of‬‭undigested‬‭waste‬ ‭‬ ‭Oxygen‬‭is‬‭an‬‭excretory‬‭product.‬‭Photosynthesis‬‭is‬‭a‬‭metabolic‬‭process‬‭(anabolic).‬ ‭‬ ‭Urinary‬‭system‬‭consists‬‭of:‬ ‭‬ ‭Pair‬‭of‬‭kidneys‬‭,‬‭renal‬‭artery‬‭and‬‭renal‬‭vein,‬‭pair‬‭of‬‭ureters‬‭,‬‭bladder,‬‭urethra.‬‭(renal‬ ‭refers‬‭to‬‭kidney)‬ ‭‬ ‭Renal‬‭arteries‬‭has‬‭more‬‭urea‬‭and‬‭less‬‭carbon‬‭dioxide‬‭than‬‭renal‬‭veins‬ ‭‬ ‭Kidney‬‭located‬‭in‬‭abdominal‬‭cavity‬‭attached‬‭to‬‭the‬‭dorsal‬‭wall‬‭behind‬‭the‬‭liver.‬ ‭‬ ‭Nephron‬‭is‬‭found‬‭in‬‭the‬‭cortex‬‭of‬‭the‬‭renal‬‭pyramid‬‭in‬‭a‬‭kidney‬ ‭‬ ‭Includes‬‭Bowman’s‬‭capsule,‬‭Proximal‬‭(first)‬‭convoluted‬‭tubule,‬‭loop‬‭of‬‭Henle,‬‭Distal‬ ‭(second)‬‭convoluted‬‭tubule‬ ‭‬ ‭Several‬‭nephrons‬‭open‬‭into‬‭the‬‭collecting‬‭duct‬‭which‬‭is‬‭a‬‭tube‬ ‭‬ ‭Blood‬‭enters‬‭kidney‬‭by‬‭renal‬‭artery‬‭and‬‭branches‬‭into‬‭glomerulus‬‭(a‬‭mass‬‭of‬‭capillaries‬ ‭in‬‭Bowman’s‬‭capsule)‬ ‭‬ ‭Afferent‬‭arteriole‬‭is‬‭wider‬‭than‬‭efferent‬‭arteriole.‬ ‭‬ ‭Heart‬‭and‬‭diameter‬‭difference‬‭of‬‭afferent‬‭and‬‭efferent‬‭arterioles‬‭create‬‭high‬‭pressure‬‭in‬ ‭glomerulus‬ ‭‬ ‭Forces‬‭part‬‭of‬‭blood‬‭plasma‬‭through‬‭the‬‭capillary‬‭walls‬‭into‬‭Bowman’s‬‭capsule‬ ‭‬ ‭Larger‬‭molecules‬‭(red‬‭blood‬‭cells,‬‭white‬‭blood‬‭cells,‬‭platelets,‬‭fats,‬‭proteins)‬‭are‬‭retained‬ ‭‬ ‭Filtrate‬‭moves‬‭of‬‭glomerulus‬‭to‬‭the‬‭three‬‭other‬‭parts.‬ ‭‬ ‭Useful‬‭materials‬‭are‬‭filtered‬‭back‬‭by‬‭capillaries‬‭surrounding‬‭the‬‭tubules.‬‭(Glucose,‬‭amino‬ ‭acids,‬‭most‬‭mineral‬‭salts)‬ ‭‬ ‭Anti-diuretic‬‭hormone‬‭(ADH,‬‭vasopressin)‬‭action‬‭regulates‬‭the‬‭concentrations‬‭of‬‭water‬ ‭and‬‭various‬‭solutes‬‭to‬‭maintain‬‭a‬‭constant‬‭water‬‭potential‬‭in‬‭the‬‭body.‬ ‭‬ ‭Less‬‭ADH‬‭means‬‭more‬‭urine.‬‭More‬‭ADH‬‭means‬‭less‬‭urine.‬‭“Anti”‬‭means‬‭Less‬‭and‬ ‭“Diuretic”‬‭means‬‭urine.‬ ‭‬ ‭Increases‬‭permeability‬‭of‬‭the‬‭distal‬‭convoluted‬‭tubules‬‭and‬‭collecting‬‭duct‬ ‭Homeostasis‬‭and‬‭Hormonal‬‭control‬ ‭‬ ‭Homeostasis‬‭is‬‭maintenance‬‭of‬‭constant‬‭internal‬‭environment‬ ‭‬ ‭Receptor,‬‭control‬‭centre,‬‭effector‬ ‭‬ N ‭ egative‬‭feedback‬‭causes‬‭body‬‭to‬‭bring‬‭opposite‬‭counterchange‬‭to‬‭changes‬‭detected‬‭to‬ ‭restore‬‭system‬‭into‬‭its‬‭steady‬‭state.‬ ‭‬ ‭Blood‬‭glucose‬‭level‬‭regulation‬‭-‬‭Liver‬‭(normal‬‭is‬‭90mg/100cm3‬‭of‬‭blood)‬ ‭‬ ‭Hyperglycemia‬‭-‬‭Temporary‬‭increase‬‭in‬‭blood‬‭glucose‬‭concentration‬ ‭‬ ‭Islets‬‭of‬‭Langerhans‬‭β-cells‬‭in‬‭pancreas‬‭are‬‭stimulated,‬‭releases‬‭hormone‬‭insulin‬ ‭‬ I‭nsulin‬‭diffuses‬‭from‬‭pancreas‬‭into‬‭(surrounding)‬‭blood‬‭capillaries,‬‭transported‬‭into‬‭liver‬ ‭and‬‭muscles‬ ‭‬ ‭Promotes‬‭conversion‬‭of‬‭excess‬‭glucose‬‭to‬‭glycogen‬‭for‬‭storage‬‭(1)‬ ‭Causes‬‭increased‬‭cellular‬‭respiration‬‭(2)‬ ‭Increases‬‭permeability‬‭of‬‭cell‬‭membrane‬‭to‬‭glucose‬‭(3)‬ ‭‬ ‭Remaining‬‭insulin‬‭sent‬‭to‬‭liver‬‭to‬‭be‬‭destroyed‬‭(deamination),‬‭removed‬‭by‬‭kidneys‬‭.‬ ‭‬ ‭Hypoglycemia‬‭-‬‭Temporary‬‭decrease‬‭in‬‭blood‬‭glucose‬‭concentration‬ ‭‬ ‭Islets‬‭of‬‭Langerhans‬‭α-cells‬‭in‬‭pancreas‬‭are‬‭stimulated,‬‭releases‬‭hormone‬‭glucagon‬ ‭‬ ‭Osmoregulation‬‭-‬‭Kidneys‬‭(regulating‬‭water‬‭potential‬‭in‬‭blood)‬ ‭‬ C ‭ ontrolled‬‭by‬‭ADH‬‭(Antidiuretic‬‭hormone),‬‭produced‬‭by‬‭hypothalamus‬‭in‬‭brain,‬ ‭released‬‭by‬‭pituitary‬‭gland‬‭,‬‭increases‬‭water‬‭reabsorption‬‭at‬‭kidney‬‭nephrons‬ ‭‬ P ‭ revents‬‭red‬‭blood‬‭cells‬‭from‬‭being‬‭affected‬‭by‬‭water‬‭potential‬‭changes‬‭by‬‭lysis‬‭or‬ ‭crenation‬ ‭‬ ‭Thermoregulation‬‭-‬‭Skin‬ ‭‬ C ‭ ontrolled‬‭by‬‭sudoriferous‬‭glands‬‭and‬‭vasodilation‬‭during‬‭heat‬‭gain,‬‭increase‬‭in‬ ‭metabolic‬‭rate‬‭and‬‭vasoconstriction‬‭during‬‭heat‬‭loss,‬‭all‬‭by‬‭hypothalamus‬ ‭‬ ‭Arterio-venous‬‭shunt‬‭vessel‬‭can‬‭constrict‬‭or‬‭dilate‬ ‭‬ D ‭ uring‬‭heat‬‭gain,‬‭arterio-venous‬‭shunt‬‭vessel‬‭constricts‬‭,‬‭blood‬‭is‬‭directed‬‭to‬‭surface‬ ‭capillaries,‬‭more‬‭heat‬‭lost‬‭by‬‭radiation‬ ‭‬ D ‭ uring‬‭heat‬‭loss,‬‭arterio-venous‬‭shunt‬‭vessel‬‭dilates‬‭,‬‭less‬‭blood‬‭is‬‭directed‬‭to‬‭surface‬ ‭capillaries,‬‭less‬‭heat‬‭lost‬‭by‬‭radiation‬ ‭‬ ‭Coordination‬‭and‬‭response‬‭involves‬‭nervous‬‭system‬‭and‬‭endocrine‬‭system‬ ‭‬ E ‭ ndocrine‬‭system‬‭controls‬‭body‬‭activity‬‭by‬‭releasing‬‭chemical‬‭messengers‬‭(aka‬ ‭hormones)‬‭into‬‭blood‬ ‭‬ H ‭ ormone‬‭-‬‭Chemical‬‭substance‬‭produced‬‭by‬‭an‬‭endocrine‬‭gland‬‭carried‬‭by‬‭blood,‬ ‭which‬‭alters‬‭the‬‭activity‬‭of‬‭one‬‭or‬‭more‬‭specific‬‭target‬‭organs‬‭and‬‭is‬‭then‬‭destroyed‬‭by‬ ‭the‬‭liver.‬ ‭‬ ‭Hormones‬‭diffuse‬‭directly‬‭into‬‭surrounding‬‭blood,‬‭hence‬‭endocrine‬‭glands‬‭are‬‭ductless‬ ‭‬ ‭Endocrine‬‭glands‬‭contain‬‭an‬‭extensive‬‭network‬‭of‬‭blood‬‭vessels‬ ‭‬ ‭Pituitary‬‭gland‬‭-‬‭“controller”‬‭of‬‭other‬‭endocrine‬‭glands,‬‭secretes‬‭ADH‬ ‭‬ ‭Hypothalamus‬‭-‬‭Regulates‬‭the‬‭secretion‬‭of‬‭pituitary‬‭hormones‬ ‭‬ T ‭ hyroid‬‭gland‬‭-‬‭Secretes‬‭thyroxine,‬‭which‬‭controls‬‭rate‬‭of‬‭metabolism‬‭and‬‭influences‬ ‭physical‬‭development‬ ‭‬ ‭Adrenal‬‭gland‬‭-‬‭Secretes‬‭adrenaline,‬‭prepares‬‭body‬‭for‬‭“fight-or-flight”‬ ‭‬ ‭Pancreas‬‭-‬‭Islets‬‭of‬‭Langerhans‬‭secrete‬‭insulin‬‭and‬‭glucagon‬ ‭‬ ‭Testes‬‭-‬‭Secretes‬‭testosterone‬ ‭‬ ‭Ovaries‬‭-‬‭Secretes‬‭estrogen‬ ‭‬ ‭Type‬‭1‬‭diabetes‬‭is‬‭insufficient‬‭insulin,‬‭Type‬‭2‬‭diabetes‬‭is‬‭insulin‬‭resistance.‬ ‭‬ ‭Human‬‭skin‬‭functions‬‭below:‬ ‭○‬ ‭Thermoregulation‬ ‭○‬ ‭Thermal‬‭insulation‬ ‭○‬ ‭Protection‬‭from‬‭physical‬‭damage,‬‭dehydration,‬‭UV‬‭rays‬ ‭○‬ ‭Energy‬‭reserves‬‭from‬‭adipose‬‭tissue‬ ‭○‬ ‭Reception‬‭of‬‭external‬‭stimuli‬ ‭○‬ ‭Vitamin‬‭production‬ ‭○‬ ‭(minor)‬‭nitrogenous‬‭excretion‬  ‭‬ ‭Consists‬‭of‬‭epidermis‬‭and‬‭dermis‬ ‭Nervous‬‭system‬ ‭‬ ‭Actions‬‭can‬‭be‬‭voluntary‬‭or‬‭involuntary‬ ‭‬ ‭Nervous‬‭system‬‭consists‬‭of‬‭Central‬‭Nervous‬‭System‬‭and‬‭Peripheral‬‭Nervous‬‭System‬ ‭‬ ‭CNS‬‭consists‬‭of‬‭brain‬‭and‬‭spinal‬‭cord‬ ‭‬ P ‭ NS‬‭consists‬‭of‬‭nerves,‬‭ganglia,‬‭sense‬‭organs,‬‭forms‬‭connection‬‭between‬‭organs‬‭and‬ ‭CNS‬ ‭‬ N ‭ erve‬‭impulses‬‭are‬‭transmitted‬‭along‬‭neurons‬‭from‬‭organs‬‭that‬‭receive‬‭stimuli‬‭at‬ ‭receptors‬‭to‬‭organs‬‭that‬‭effect‬‭change‬‭at‬‭effectors‬‭.‬ ‭Example:‬‭Nerve‬‭impulse‬‭transmitted‬‭from‬‭pain‬‭receptor‬‭to‬‭spinal‬‭cord‬‭then‬‭to‬‭muscle‬ ‭‬ ‭Cell‬‭body‬‭of‬‭neuron‬‭contains‬‭nucleus‬‭and‬‭cytoplasm‬ ‭‬ S ‭ ensory‬‭neuron‬‭(receptor)‬‭-‬‭transmit‬‭nerve‬‭impulse‬‭from‬‭sense‬‭organs‬‭to‬‭CNS‬‭(optic‬ ‭nerve)‬ ‭‬ R ‭ elay‬‭neuron‬‭(intermediate)‬‭-‬‭found‬‭within‬‭CNS,‬‭receive‬‭impulses‬‭from‬‭sensory‬‭or‬‭other‬ ‭intermediate‬‭neurons,‬‭relaying‬‭to‬‭other‬‭intermediate‬‭or‬‭motor‬‭neurons.‬ ‭‬ ‭Motor‬‭neuron‬‭(effector)‬‭-‬‭transmit‬‭nerve‬‭impulse‬‭from‬‭CNS‬‭to‬‭effectors‬ ‭‬ ‭Parts‬‭of‬‭a‬‭neuron‬‭(below)‬ ‭‬ ‭Dendron‬‭-‬‭nerve‬‭fibres‬‭that‬‭transmit‬‭nerve‬‭impulses‬‭towards‬‭the‬‭cell‬‭body‬ ‭‬ ‭Dendrite‬‭-‬‭receiver‬‭of‬‭nerve‬‭impulses‬‭from‬‭other‬‭neurons‬ ‭‬ ‭Axon‬‭-‬‭nerve‬‭fibre‬‭that‬‭carry‬‭impulses‬‭away‬‭from‬‭the‬‭cell‬‭body‬ ‭‬ ‭Myelin‬‭sheath‬‭-‬‭layer‬‭of‬‭fatty‬‭substance‬‭that‬‭shields‬‭and‬‭insulates‬‭the‬‭nerve‬‭fibre‬ ‭‬ N ‭ ode‬‭of‬‭Ranvier‬‭-‬‭region‬‭where‬‭myelin‬‭sheath‬‭is‬‭absent‬‭,‬‭speeding‬‭up‬‭transmission‬‭by‬ ‭allowing‬‭impulses‬‭to‬‭jump‬‭from‬‭node‬‭to‬‭node‬ ‭‬ ‭Axon‬‭terminals‬‭-‬‭transmit‬‭nerve‬‭impulses‬‭to‬‭the‬‭effector‬ ‭‬ ‭Motor‬‭end‬‭plate‬‭-‬‭junction‬‭between‬‭axon‬‭terminals‬‭and‬‭muscle‬‭fibre‬ ‭(If‬‭in‬‭italics,‬‭“axon‬‭terminals”‬‭were‬‭previously‬‭mistaken‬‭for‬‭dendrites)‬ ‭‬ ‭Motor‬‭neuron‬‭has‬‭terminal‬‭cell‬‭body,‬‭numerous‬‭short‬‭nerve‬‭fibres‬‭lead‬‭into‬‭it‬ ‭‬ ‭Sensory‬‭neuron‬‭has‬‭non-terminal‬‭cell‬‭body,‬‭single‬‭long‬‭nerve‬‭fibre‬‭leads‬‭into‬‭it‬ ‭‬ N ‭ erve‬‭fibre‬‭is‬‭a‬‭strand‬‭of‬‭cytoplasm‬‭extending‬‭from‬‭cell‬‭body,‬‭specialised‬‭in‬‭transmitting‬ ‭nerve‬‭impulses‬ ‭‬ ‭A‬‭nerve‬‭is‬‭a‬‭bundle‬‭of‬‭nerve‬‭fibres,‬‭enclosed‬‭in‬‭a‬‭sheath‬‭of‬‭connective‬‭tissue‬ ‭‬ S ‭ ensory‬‭nerve‬‭fibres‬‭conduct‬‭nerve‬‭impulses‬‭from‬‭sense‬‭organs,‬‭while‬‭motor‬‭nerve‬ ‭fibres‬‭conduct‬‭nerve‬‭impulses‬‭to‬‭effectors‬ ‭‬ ‭Spinal‬‭nerves‬‭contain‬‭both‬‭fibres,‬‭called‬‭mixed‬‭fibres‬ ‭‬ ‭A‬‭synapse‬‭is‬‭a‬‭junction‬‭between‬‭two‬‭neuron‬‭s‬‭or‬‭between‬‭a‬‭neuron‬‭and‬‭an‬‭effector‬ ‭‬ N ‭ eurons‬‭rarely‬‭contact‬‭each‬‭other,‬‭impulses‬‭do‬‭not‬‭transmit‬‭directly‬‭from‬‭neuron‬‭to‬ ‭neuron‬ ‭‬ N ‭ erve‬‭impulses‬‭are‬‭transmitted‬‭electrically‬‭through‬‭neurons‬‭,‬‭chemically‬‭across‬ ‭synapses‬ ‭‬ ‭Ensures‬‭one-directional‬‭flow‬‭of‬‭impulses‬ ‭‬ ‭Impulses‬‭are‬‭carried‬‭across‬‭synapses‬‭via‬‭neurotransmitters‬‭(aka.‬‭Chemical‬‭means)‬ ‭‬ S ‭ pinal‬‭cord‬‭passes‬‭through‬‭vertebral‬‭column,‬‭which‬‭protects‬‭spinal‬‭cord‬‭(very‬‭important,‬ ‭break‬‭=‬‭paralysed‬‭from‬‭above‬‭the‬‭head‬‭down)‬ ‭‬ R ‭ elays‬‭impulses‬‭in‬‭and‬‭out‬‭at‬‭any‬‭point‬‭along‬‭the‬‭cord,‬‭up‬‭and‬‭down‬‭the‬‭body,‬‭to‬‭and‬ ‭from‬‭the‬‭brain‬ ‭‬ ‭Spinal‬‭cord‬‭contains‬‭cell‬‭bodies‬‭,‬‭synapses‬‭,‬‭and‬‭relay‬‭neurons,‬‭which‬‭is‬‭grey‬‭matter‬‭.‬ ‭‬ ‭Relays‬‭following:‬ ‭○‬ ‭Sensory‬‭neuron‬‭to‬‭brain‬ ‭○‬ ‭Brain‬‭to‬‭motor‬‭neuron‬  ‭○‬ ‭Sensory‬‭neuron‬‭to‬‭motor‬‭neuron‬‭(reflex‬‭action)‬ ‭‬ ‭Outer‬‭part‬‭of‬‭the‬‭cord‬‭contains‬‭longitudinally-running‬‭fibres‬‭,‬‭called‬‭white‬‭matter‬‭.‬ ‭‬ S ‭ ensory‬‭fibres‬‭enter‬‭through‬‭the‬‭dorsal‬‭root‬‭,‬‭motor‬‭fibres‬‭leave‬‭through‬‭the‬‭ventral‬ ‭root‬‭.‬ ‭‬ C ‭ ell‬‭bodies‬‭of‬‭sensory‬‭fibres‬‭are‬‭si