Digestion II Glucose Absorption Lumen of small intestine Na Glucose Na glucose co transporter Cytoplasm of intestinal cell K Na K ATPase Glucose transport protein Blood vessel Na Glucose Glucose enters an intestinal cell along with Na driven by the Na concentration difference between the lumen of the intestine and the cytoplasm of the cell Na concentration is kept low inside the cell by the action of the Na K pump Glucose exits the intestinal cell passively by a glucose transport protein Glucose exits the intestinal cell passively by a glucose transport protein Glucose enters an intestinal cell along with Na driven by the Na concentration difference between the lumen of the intestine and the cytoplasm of the cell Na concentration iskept low inside thecell by the action ofthe Na K pump Small Intestine Summary Duodenum Jejunum Ileum LONG 3 5x height High S A Mucosal folds Villi microvilli Chemical Digestion Absorption Protein and Carbs Most fats Water soluble vitamins Carbohydrate digestion Protein digestion Nucleic acid digestion Fat digestion Fig 41 13 Oral cavity pharynx esophagus Stomach Polysaccharides starch glycogen Disaccharides sucrose lactose Salivary amylase Smaller polysaccharides maltose Proteins Pepsin Small polypeptides Polypeptides Smaller polypeptides Pancreatic carboxypeptidase Amino acids Small peptides Lumen of small intes tine Polysaccharides Pancreatic amylases Maltose and other disaccharides Pancreatic trypsin and chymotrypsin Pancreatic nucleases DNA RNA Fat globules Bile salts Fat droplets Nucleotides Pancreatic lipase Glycerol fatty acids monoglycerides Epithelium of small intestine brush border Disaccharidases Dipeptidases carboxypeptidase and aminopeptidase Monosaccharides Amino acids Nucleotidases Nucleosides Nucleosidases and phosphatases Nitrogenous bases sugars phosphates Hepatic Portal System Liver Functions Reabsorption of water minerals ions Na Cl Formation storage and expulsion of feces rectum anus Houses bacteria Provide beneficial nutrients and vitamins Cheap protein powder Lactose intolerance Beans Cellulose Appendix what the what Large Intestine Cellulose Complex carbohydrate or polysaccharide composed of Glucose monomers Basic building block of cell walls in plants 33 of vegetable matter and the most abundant natural organic compound on Earth VERY dense stable and indigestible by animals Only made by plants fungi unicellular orgs Cellulase hydrolyzes glycogen into glucose monomers Think write share Can Wisconsin s beloved Holsteins digest the cellulose in the grass they eat Why or why not Foregut Fermenter Ruminants Stomach Esophagus Rumen Reticulum Omasum Abomasum Small intestine Cecum Large intestine Rectum Cattle Sheep Goats 4 chambered stomach The GI tract of a ruminant is suited for harboring microbes mixing and retention Takes a lot of mechanical digestion stirring and time Chewing cud Rumen Reticulum house bacteria and mix food Omasum is highly folded and absorbs most of the SCFa s Abomasum is highly acidic kills bacteria and denatures proteins Symbiosis of Fermentation Host Animal Provide a safe stable moist environment Constant pH Constant temperature Provide cellulose fats protein Bacteria Have cellulase Provide SCFa s energy Protein when they die are converted to a a s Vitamins Hindgut Fermenter Horses Koalas Rabbits Termites Rhinos Tapirs Stomach and small intestine function normally like our own Most energy is derived from the mid hindgut less mixing less chewing less efficient Visibly apparent in poo A lot of the by products of symbiotic fermentation are not able to be absorbed and would be wasted Caprophagy Cecotropes Proteins vitamins Esophagus Stomach Small intestine Cecum Large intestine Rectum minerals Digestion LLOs 1 Know the foregut midgut and hindgut s roles in digesting an animal s diet 2 Know where and how the three macromolecules break down in foregut and midgut and how they are absorbed into the body 3 Understand the necessity of a strongly acidic stomach and how protein digestion occurs within the stomach 4 Describe how the stomach creates and maintains an acidic stomach 5 Describe how the small Intestine works with the pancreas and liver to finish digestion and start complete absorption 6 Know that the large intestine retains digesta long enough to absorb water and nutrients before expulsion 7 Compare and contrast hindgut vs foregut fermentation strategies Know where fermentation happens for each and what strategies are employed to maximize energy and nutrient acquisition