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Ques*ons  

•  Why  does  the  insect  circulatory  system  operate  without  regard  to  oxygen  demand  of  the  *ssues?  

•  What  is  the  circula*on  of  material  inside  an  individual  cell  called?  

Ques*on  

•  What  are  the  advantages  to  not  having  nuclei  in  red  blood  cells?  

Ques*ons  

•  Discuss  the  differences  between  the  2-­‐chambered  and  4-­‐chambered  heart  in  terms  of  blood  pressure.  

•  What  is  the  advantage  of  a  4-­‐chambered  heart  over  a  3-­‐chambered  heart?  

4/11/12  

2  

Biology:

What is Life? Cellular Structure: the unit of life, one or many

Growth: cell enlargement, cell number

Evolution: long term adaptation Behavior: short term response to stimuli Reproduction: avoid extinction at death

Metabolism: photosynthesis, respiration, fermentation, digestion, gas exchange, secretion, excretion, circulation –processing materials and energy

Movement: intracellular, movement, locomotion

Properties of Life

hEp://nikonrumors.com/2009/04/05/did-­‐you-­‐register-­‐for-­‐the-­‐nikon-­‐rumors-­‐forum.aspx/  

Food  Capture  and  Diges*on  

Feeding  strategies  and  adapta*ons  

Food  Capture  

Intracellular    Food  digested  inside  the  cell.      Waste  must  be  eliminated  from  cell.  

Extracellular    Food  digested  outside  the  cell  (cavity,  gut).    Only  digested  products  enter  cells.  

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Intracellular  Diges*on  

•  Mainly  seen  in  pro*sts.  – Amoeba,  Paramecium  

hEp://www.biofor*fied.org/2010/03/glowing-­‐phagocytosis/   hEp://www.sciencephoto.com/media/149302/enlarge  

Anima*on  of  intracellular  diges*on  in  poriferans.  

hEp://www.biology.ualberta.ca/courses.hp/zool250/anima*ons/Porifera.swf  

Food  Diges*on  

Intracellular    Food  digested  inside  the  cell.      Waste  must  be  eliminated  from  cell.  

Extracellular    Food  digested  outside  the  cell  (cavity,  gut).    Only  digested  products  enter  cells.  

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Extracellular  Diges*on  Strategies  

•  Suspension  feeders  – Feeding  on  par*cles  suspended  in  water  

•  Deposit  feeders  – Feeding  on  surface  or  subsurface  debris  

•  Mass  feeders  – Feeding  on  mass  chunks  of  plants  or  animals  

hEp://underwater.com.au/content/8169/coral_polyps.jpg  

hEp://www.biologyjunc*on.com/images/earthw1.jpg  

hEp://keep3.sjfc.edu/students/naa07113/e-­‐port/squirrel.jpg  

Suspension  Feeders  

•  Feeding  on  bacteria,  phytoplankton,  zooplankton,  detritus  

•  Adapta*ons:  – Filters  – Setae  – Tentacles  or  tube  feet  

hEp://ikandoank.blogspot.com/2011/06/culture-­‐plankton-­‐par*cularly.html  

Filter  Feeders  

hEp://depts.washington.edu/`lk12/links/StudentProjects/Tun.biology.html   hEp://jklsciencelab.weebly.com/clam-­‐dissec*on.html   hEp://wn.com/bivalve  

hEp://prospect.rsc.org/blogs/cw/2008/03/  

SubPh.  Urochordata  “Tunicate”   Cl.  Bivalvia  

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Porcelain  crab  suspension  feeding  

hEp://www.youtube.com/watch?v=i1NPrDVUSSI  

Barnacles  suspension  feeding  

hEp://www.youtube.com/watch?v=25F7xMVNt-­‐w  

Tentacle  or  tube  feet  suspension  feeding  

hEp://www.youtube.com

/watch?v=8uZJVSFw

ixY&feature=related   Cl.  Crinoidea  

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Deposit  Feeders  

•  Direct  deposit  feeding  – Swallow  large  quan**es  of  dirt/sediment  

•  Selec*ve  deposit  feeding  – Feed  only  on  the  top  layer  of  dirt/sediment  

Direct  deposit  feeders  

•  Examples:  – earthworms,  polycheate  annelids  – Can  digest  up  to  500x  their  weight  a  day!  

hEp://jwswj.com/blog/?cat=3   hEp://www.fossilmuseum.net/fossilpictures-­‐wpd/annelid/annelid.jpg  

Selec*ve  deposit  feeders  

•  Only  feed  on  the  top  layer  of  sediment  – This  is  where  most  of  the  bacteria,  detritus,  and  pro*sts  are  found  

– This  layer  also  includes  all  of  the  feces  deposited  from  other  animals  

hEp://www.sailwhisper.com/logs/news_20080628.php   hEp://www.starfish.ch/c-­‐invertebrates/seewalzen.html  

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Selec*ve  deposit  feeders  

•  Without  something  ea*ng  all  the  “organic  debris,”  it  would  accumulate,  which  would  increase  bacterial  growth  and  eventually  lead  to  anaerobic  condi*ons  and  the  growth  of  sulfur-­‐reducing  bacteria  

hEp://www.flickr.com/photos/rjcassling/3535437278/  

Sea  cucumber  poo  is  alkaline  

Sea  cucumber  poo  deposits  CaCO3  

www.treehugger.com  

Mass  Feeders  Evolu0on  of  the  gut  

•  Mass  Feeders  – Consume  chunks  of  plant  or  animal  maEer  

•  In  most  cases,  these  chunks  are  processed  in  a  gut  or  gut  cavity  

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Gastrovascular  cavity  (Gastrodermis)  

Ectoderm  

Endoderm  (gastrodermis)  

General  cnidarian  polyp  (P.  Cnidaria)    No  circulatory  system    Food  must  reach  cells  via  diffusion  

Incomplete  gut  

•  Ph.  Platyhelminthes  

•  Food  is  eaten,  digested,  and  removed  from  the  same  opening  

•  Why  is  this  branched?  

hEp://www.tutornext.com/phylum-­‐platyhelminthes/7091  

The  complete  gut  advantage  

•  Some  advantages  of  a  complete  gut:  – Long  tube  moving  food  in  one  direc*on  

•  can  fit  more  food  in  gut  (compare  to  incomplete  gut)  

– Specializa*on  of  the  gut  •  Physical  /  chemical  processes  can  be  separated  

hEp://www.tutornext.com/phylum-­‐platyhelminthes/7091  

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Complete  Gut  

•  Mouth  and  anus  present  

•  Ph.  Nematoda  

•  Specializa*on  of  gut  seen  

hEp://www.reddragonpoEery.com/a/aniphy/Helminthes/nematoda  

Pharynx  

Intes*ne  

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Earthworms also have a complete gut

Cl.  Oligochaeta  

Gut  specializa*on  

•  Esophagus  /  Pharynx  –  muscles  

•  Crop  –  Storage  

•  Gizzard  – Mechanical  processing  

•  Intes*ne  –  Enzyma*c  processing  –  Nutrient  uptake  

©1996 Norton Presentation Maker, W. W. Norton & Company

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Monday  

4  Weeks  Leq!  

Ques*on  

•  Mul*cellular  organisms  are  usually  [intracellular/extracellular]  feeders.  

•  Sponges  (Phylum  Porifera)  are  [intracellular/extracellular]  feeders.  

•  Intracellular  feeding  becomes  less  efficient  as  the  surface  area/volume  ra*o  [rises/lowers].  

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Ques*on  

•  What  is  the  difference  between  a  suspension  feeder  and  a  deposit  feeder?  

•  What  are  some  advantages  of  a  complete  gut  over  an  incomplete  gut?  

Diges*ng  your  food  by  relying  on  bacteria  takes  a  long  *me  

•  Bacteriocytes  hold  mutualis*c  bacteria  

•  Crop  diver*cula  extended  to  hold  even  more  blood  

•  One  meal  may  take  6  months  to  digest  

hEp://accessscience.com/content/Hirudinea/319100  

Intes.ne  of  a  4  cm  svl  bullfrog  tadpole  is  120  cm  long!  

Herbivore  gut  length  

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Tadpole  and  metamorphosed  frog  diges.ve  system.  

herbivore  predator  

Rumen  fermenter  –  speeding  up  diges*on  

hEp://www.mun.ca/biology/scarr/Ruminant_Diges*on.htm  

Horse  Hind-­‐gut  fermenter  

hEp://www.starstruckranch.com/supplements.htm  

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Mass  feeders  

Herbivores    Teeth  modified  to  rasp,  cut  

Carnivores    Teeth  modified  to  tear,  rip  

hEp://en.wikipedia.org/w

iki/File:Cow_ea*ng_straw

_new_forest.jpg   hE

p://ho

p2wilson

.wikisp

aces.com

/Joh

n  

hEp://www.blm.gov/id/st/en/prog/wildlife/herbivores.html  

Herbivore  teeth  

hEp://www.mathema*cal.com/mammothteentooth.gif   hEp://etc.usf.edu/clipart/41400/41438/teeth_41438_lg.gif  

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Carnassial  teeth  Canine  teeth  

hEp://ijolite.geology.uiuc.edu/02sprgclass/geo143/lectures/lect20.html  hEp://www.geol.umd.edu/~jmerck/bsci392/lecture13/lecture13.html  

Canine  

Ques*ons  

•  How  are  waste  products  handled  in  intracellular  and  extracellular  diges*on?  

•  What’s  the  difference  between  direct  deposit  and  selec*ve  deposit  feeders?  

Ques*ons  

•  How  are  waste  products  handled  in  intracellular  and  extracellular  diges*on?  

•  What’s  the  difference  between  filter  feeders  and  suspension  feeders?  

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Food  Diges*on  

 CH.  43  

Molecules  

Mass  Feeder  

hEp://www.youtube.com

/watch?v=m

LVDwlrSq5U

 

The  Radula  hEp://en.w

ikipedia.org/wiki/File:Snail_radula_w

orking.png   hEp://www.midnightsunschool.com/Katchemak_Bay/mollusks.html   hEp://shells.tricity

.wsu.edu

/Arche

rdShellCollec*on

/Illustra*o

ns/Radula.html  

hEp://www.scielo.br/scielo.php?pid=S1519-­‐69842007000400019&script=sci_arEext  

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Mass  Feeder  

Ques*on  

What  happens  to  the  food  aqer  it’s  eaten?  

Molecules  of  interest  

•  Carbs  and  Lipids  more  common  •  Lipids  carry  the  most  energy  (9  kcal  vs.  4  kcal)  

•  What  do  you  want  on  your  toast?  – BuEer,  Jam/Jelly,  Peanut  BuEer  

Carbohydrates   Lipids   Proteins  

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The human digestive system preview:

amylase

pepsin, HCl

bile (emulsifier) trypsin, amylase,

H2CO3 (alk), lipase

subunit absorption bacterial culture

water reabsorption waste holding, elimination

acidic  por.on  

alkaline  por.on  

hEp://www.sciencephoto.com/media/149302/enlarge  

The  mouth  

•  Salivary  glands  produce  amylase  to  breakdown  carbohydrates  (starch)  

•  The  tongue  secretes  lipase  enzymes  which  begin  to  breakdown  lipids  

hEp://www.3dscience.com/3D_Images/Human_Anatomy/Diges*ve/Open_Mouth.php  

Stomach  

•  Highly  muscular  organ    – Some  mixing  – Creates  a  uniform  consistency  

•  Releases  Hydrochloric  acid  (HCl)  

•  Par*al  diges*on  of  proteins  

Fig.  43.8  pg  966  

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Stomach  

•  Diges*on  (denaturing)  of  proteins  by  acid  •  2-­‐3  pH  

– Unfolding  proteins  (loss  of  2o  and  3o  structure)  – Pepsin  =  enzyme  denatures  proteins  

– Why  doesn’t  pepsin  dissolve  our  own  cells?  •  Stored  in  cells  and  released  into  lumen  as  pepsinogen  •  Pepsinogen  becomes  pepsin  in  presence  of  acid  

Stomach  

How  does  the  acid  get  into  the  stomach?    H20  +  CO2  à          H2CO3            à  H+  +  HCO3  

                                         Carbonic  acid                          bicarbonate  H+  ac*vely  pumped  into  lumen  by  ATPase  (requires  energy)    

Concentra*on  gradient  ~3  mill  to  1  

Stomach  acid  Why  aren’t  we  diges*ng  ourselves?  

•  Stomach  lining  safe  because  of  mucous  

•  Stomach  acids  do  not  cause  most  ulcers  

•  Helicobacter  pylori  (published  1983,  Nobel  Prize  2005)  

•  Self  inflicted  research!  

•  Who  wants  yogurt?  

hEp://www.humenhealth.com/helicobacter-­‐pylori-­‐2  

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Small  Intes*ne  

•  Enzymes  added  to  the  slurry  (chyme)  – Enzymes  provided  by  the  pancreas  and  liver  

•  Nutrients  absorbed  selec*vely  and  ac*vely  

•  Keyword  for  small  intes*ne:  surface  area!  

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An intestinal cross section reveals the increased surface area:

Fold  

Lumen  

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Villi line the folds to increase the surface area of the absorptive regions of the intestine.

villi  

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Here you can see the microvilli from a single villus

villus

microvilli

Surface  area  

~20  m  long  +  Folds  +  Villi  +  Microvilli  =  

 2  million  cm2  =Tennis  court!  

Fig  43.11  pg  969  

Small  Intes*ne  Protein  diges0on  

•  Protein  diges*on  completed  via  proteases  –  Inac*ve  proteases  abundant  in  pancreas,  SI  – Trypsinogen  changed  to  trypsin  (by  protein,  not  H+)  – Trypsin  ac*vates  many  other  proteases  

Fig  43.12  pg  970  

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Digest:  the  Rest  

Who’s  here  today?  Who  are  we?  

Team  Bazinga  winner  by  one  vote!  

Amino acids ready for absorption in small intestine

Protein digestion:

His Glu Tyr Thr Lys His Glu Ser Arg Asp Trp Thr Phe amino end carboxyl end

Stomach

Pancreas

pepsin pepsin

His Glu Tyr Thr Lys His Glu Ser Arg Asp Trp Thr Phe

His Glu Tyr Thr Lys His Glu Ser Arg Asp Trp Thr Phe

His Glu Tyr Thr Lys His Glu Ser Arg Asp Trp Thr Phe

His Glu Tyr Thr Lys His Glu Ser Arg Asp Trp Thr Phe

trypsin trypsin chymotrypsin chymotrypsin

carboxypeptidase aminopeptidase

dipeptidase dipeptidase dipeptidase dipeptidase

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Small  Intes*ne  Lipid  diges0on  

•  Pancreas  secretes  enzymes  to  breakdown  fats  

•  Fats  insoluble  in  water,  tend  to  form  large  globules  –  Bile  salts  (actually  lipids)  emulsify*  the  lipids  

 *To  combine  by  making  the  lipid  globs  smaller  

•  Brought  into  the  cells  and  transported  to  storage  in  mul*ple  forms  –  Triglycerides,  faEy  acids,  glycerols  

Bile  

What  is  Bile?  •  Bile  is  a  complex  fluid  

containing  water,  electrolytes  and  a  baEery  of  organic  molecules  including  bile  acids,  cholesterol,  phospholipids  and  bilirubin    

•  “Bile  Salt”  

What  is  the  func.on  of  Bile?  •  Bile  “salts”  aid  in  diges*on  

of  fats  by  emulsifying  them.  

Think  oil,  water,      and  soap                      fat,    food,        and  bile  

hEp://www.vivo.colostate.edu/hbooks/pathphys/diges*on/liver/bile.html  

Do  it  again!  

Figure  43.13  pg  971  

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Emulsifica*on  

Emulsifica*on:  Separa*ng  large  globs  of  fat  into  smaller  globs  in  order  to  increase  the  available  surface  area.    Increased  surface  area  leads  to  faster  diges*on  by  enzymes  

hEp://www.youtube.com/watch?v=fJCVLG3YNJk&feature=related  

Small  Intes*ne  Carbohydrate  diges0on  

•  Polysaccharides  broken  down  further  into  disaccharides  and  monosaccharides  by  amylase  

•  Unique  enzymes  break  down  disaccharides  into  monosaccharides  – Examples:  lactase,  maltase  

Digestion of polysaccharides

amylase amylase amylase Starch

maltase maltase Maltose Maltose Glucose Glucose

Glucose Glucose Glucose Glucose Glucose Glucose

These  monosaccharides  are  ready  for  absorp.on  from  the  diges.ve  system.  

glu   glu   glu   glu   glu   glu  

α-­‐1,4  glycosidic  bond  

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Summary of macromolecule digestion into subunits Disaccharides

maltose sucrose lactose

Monosaccharides

gluose frucose

galactose

Polysaccharides

starch (amylose)

salivary amylase pancreatic amylase

intestinal maltase sucrase lactase

Proteins Peptides Amino Acids Endopeptidases: stomach pepsin

pancreatic trypsin pancreatic chymotrypsin

Exopeptidases: pancreatic intestinal

Fats (triglycerides) Emulsified fats liver bile

monoglycerides

fatty acids glycerol

direct absorption

pancreatic lipase

Diges*on  Review  

Fig  43.6  pg  964  

Essay  Ques*ons  •  Trace  the  diges*on  of  [protein,  carb,  lipid]  throughout  the  human  diges*ve  system.  Include  organs,  func*ons,  processes,  enzymes,  star*ng  molecules,  and  products.  

•  List  all  the  different  names  for  carbohydrates,  proteins,  and  lipids.  What  do  these  names  signify?  

•  Describe  how  the  process  of  ac*va*ng  both  pepsin  and  trypsin  are  similar  and  different.  

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Adapta*ons  

•  All  animals  need  proteins,  carbs,  lipids  – What  about  the  herbivores  and  cellulose  diges*on?  

– Prokaryotes  are  needed  for  cellulose  breakdown.  

•  How  have  herbivores  adapted  to  a  plant  diet?  –  Increase  surface  area  and  volume  of  gut!  

•  Long  intes*nes  •  Rumen  fermenta*on  •  Hind  gut  fermenta*on