BY 124 1st Edition Lecture 15 Outline of Last Lecture Chapter 41 I II III IV V VI VII VIII IX Essential Compounds Enzymatic Hydrolysis Groups How animals feed The appearance of an alimentary canal Processing stages What is food In mouth Crucial diagram for studying Outline of Current Lecture Chapter 41 cont I II III IV V In stomach Hormones Small intestine Other organs used in digestion a Liver b Gall bladder c Bile d Pancreas e Cecum f Large intestine Nutrition Current Lecture Chapter 41 cont I II In stomach a Lots of gastric pits Figure 41 11 i Mucous cells mucus ii Parietal cells hydrochloric acid HCl iii Chief cells pepsinogen can be changed to pepsin by HCl given off by parietal cells Hormone to excite or set in motion a Zymogens inactive enzymes III IV b Gastrin produced by lower part of stomach Gets in blood and the moves into top of stomach i Helps release of pepsin ii Controlled by nervous system and other hormonal release c Pepsin reduces proteins to small polypeptides d HCl not necessarily a hormone breaks things down because very acidic i Breaks down glue between cells which is important because it increases surface area ii Antimicrobial agent for stomach iii Thought to have caused ulcers 1 Found that ulcers were actually caused by Helicobacter pylori e Bolus is turned into chime f Chyme leaves pyloric sphincter g Have fast growing cells why it is hard for those on chemotherapy to eat Small Intestine Figure 41 9 a Small and large intestines i Small intestine has smaller diameter than large intestine b Figure 41 17 i Carnivore longer small intestine short cecum and shorter large intestine ii Herbivore shorter small intestine long cecum and longer large intestine c 3 parts i Duodenum 1 Where most digestion occurs ii Jejunum iii Ileum 1 Where most of absorption of nutrients occurs microvilli a brush border b Inside villi Figure 41 13 i Blood capillary goes into blood 1 Amino acids and glucose ii Lacteal goes into lymph vessels lymphatic system 1 Fat iii Uses active diffusion by using pumps iv Fat moves into epithelial cells and they are formed into triglycerides where they are coated with phospholipids cholesterol and proteins to create a chylomicron which passes into lacteals d Breaks down nucleic acids coming from pancreas by breaking phosphodiester bond and turning them into nucleotides Other organs used in digestion Figure 41 9 a Liver i Constantly makes and secretes bile that is stored and released through the gall bladder and contains the breakdown products of hemoglobin ii Adds color to feces b Gallbladder i Does not make anything ii JUST stores and releases bile iii Releases bile when cholecystokinin CCK is triggered by food entering intestines 1 CCK also effects pancreas c Bile not an organ i Does not digest anything 1 Emulsification breaks up into smaller pieces kind of like shaking a ball of oil in water and seeing it split up a Increases surface area ii Alkaline d Pancreas Figure 41 19 i Pancreatic ii Secretes digestion enzymes iii Helps neutralize chyme by producing sodium bicarbonate 1 Results in basic environment iv Releases secretin secretin tells pancreas to release sodium bicarbonate v CCK is told to release its enzymes here too vi Enterogasterones 1 CCK and secretin 2 Tells stomach to slowly release chyme vii 3 zymogens released by pancreas in response to CCK in lumen of duodenum 1 Trypsinogen releases trypsin which can react to make more trypsin or and it can activate the next two zymogens 2 Procarboxypeptidase 3 Chymotrypsinogen viii Endopeptidase and exopeptidase 1 Pepsin trypsin and chymotrypsin endopeptidases a Break bonds in middle of polypeptide chain b Some can be very specific 2 Aminopeptidase and carboxypeptidase exopeptidases a Cut from the end b Aminopeptidase cuts one amino acid in on amino end c Carboxypeptidase cuts one amino acid in on carboxyl end e Cecum i Junction between small and large intestine ii Appendix located just below it 1 Thought to be a vestigial organ iii Cows use it to store microorganisms to help breakdown cellulose in the plants that they eat f Large intestine i 2 parts 1 Colon a Ascending b Transcending c Descending 2 Rectum a Ends with the anus ii Basically does the final check on water iii Gets rid of salts V iv Escherichia Coli E Coli v Rectum will get filled and will send a signal to brain to release the buildup of fecal material vi Material can spend anywhere from 12 24 hours in the large intestine Nutrition a Essential amino acids for adults Figure 41 2 i Methionine ii Valine iii Threonine iv Phenylalanine v Leucine vi Isoleucine vii Tryptophan viii Lysine b Essential means that your body cannot make them and that you have to get them in your diet c Basal metabolic rate amount of energy measuredin calories needed to maintain your body at rest d Fats give 1 5x more energy than protein and carbohydrates e Table 41 1 vitamin requirements of humans i Only have to know which are fat and water soluble f Table 41 2 mineral requirements of humans i Trace minerals only need a little bit of them