Grade 8 INTRA - Human Alimentary Canal
- 1. awan
- 22. Mouth Ptialin / Amylas e Starch disaccharide / glucose Stomach Pepsi n Renni n HCl Protein pepton To precipate kasein (milk protein) To kill germ in the foods Pancrea s Trypsi n Amylas e Lipase pepton amino acid Starch glucose Fats/ lipid fatty acids + glycerol
- 23. Small intestin e Erepsin Enterokina se Protein amino acid Erepsinogen Erepsin Fats/ lipid fatty acids + glycerol Maltose glucose + glucose Lactose glucose + galactose Sucrose glucose + fructose Lipase Maltase Lactase Sucrase/ Sacarase
- 24. Name of part Clue Usually held close by sphicters, stretching of the part above this causes the sphincters to relax About 25 cm long part of the tract where most of the digestion takes place Where ingestion of food takes place For temporary storage of faeces Where involuntary contractions of the muscles in the digestive tract first begin Muscular organ where bacteria present in the ingested food are killed Where chyme becomes known as faeces as water is removed Longest part of the digestive tract Anus Duodenum Mouth Rectum Oesophagus Stomach Colon Ileum 1a
- 25. 2b Chewing breaks large pieces of food into smaller and smaller pieces which increases the surface area over which enzyme action will take place 2d 1. Food is chewed, mixed with saliva, rolled into a ball and pushed to the back of the mouth by the tongue 2. Tongue is raised towards hard palate, pushing food into the pharynx 3. Process under voluntary control up this point, subsequent actions are under involuntary control 4. Soft palate rises to cover entrance to nasal cavity 5. Larynx rises towards epiglottis 6. Weight of food bends epiglottis to cover entrance to windpipe, and finally food is directed towards the oesophagus
- 26. 2e Name the movement of food described in .................................. peristalsis Movement of food in the digestive tract as a whole Movement of food in the stomach Brought about by muscles lining walls of tract Movements are involuntary Take place in one direction Serves to mix food with enzymes and move it along Slow Brought about by muscles lining walls of tract Movements are involuntary Can take place in various directions Also to physically break food into smaller pieces Vigorous at times
- 27. 3a Feature which aids absorbtion Part of small intestine Increased surface area Reduced distance over which nutrients must move Food brought close to walls Presence of a diffusion gradient Length (6 m) Many internal foldings Narrow diameter Muscular walls Network of blood vessels to remove absorbed substances 3b, (i) Villus 3b, (ii) To protect the intestinal cells from being digested by the enzymes in the chyme/ to reduce abrasion by food particles / to provide lubrication and aid movement of chyme along the tract
- 28. 1 (a) Methode of dispresing fat droplets : (b) Non-enzyme which brings about (a): (c) Part of the digestive tract where (a) takes place: (d) Producer of (b): (e) A non-enzyme which denatures proteins: (f) Enzyme activated by (e) which acts on milk proteins: (g) Place which produced in the mouth: (h) Enzyme which begins hydrolysis of polypeptides: (i) Structure controlling release of chyme into the duodenum: (j) Creates the correct pH for enzyme action in the duodenum: (k) Enzyme produced in the mouth: (l) Subtance which (k) acts on: (m) Inactive form of enzyme produced by the pancreas: (n) Substance which the active form of (m) works on: emulsification bile salts duodenum liver Hydrochloric acid rennin stomach pepsin Pyloric sphincter Sodium bicarbonate Salivary amylase Polysaccharide or starchtrypsinogen protein
- 29. 1 (o) Organ, which is not part of digestive tract, but produce digestive enzymes (p) Enzyme which can only work after (a) has taken place: (q) Substrate which (p) works on: (r) Products of the action of (p): (s) Enzyme which activates the inactive enzyme (m): (t) Site of production of (s): (u) Class of enzymes which act on (l): (v) Class of enzymes to which (f) and (h) belong to: (w) Final product of the action of (v) (x) Final product of the action of (u) (y) Part of digestive tract where (p) begins action: (z) Part of digestive tract where (h) acts: pancreas lipase fats Fatty acids & glycerolenterokinase Intestinal cells amylase proteases Amino acids Simple sugars / glucoseduodenum stomach
- 30. 2a Polymers of sugars called ___________________are acted on by the class of enzymes called ______________________. The bonds linking the units are broken one at a time until only the __________________________ remain. 2b Fats must first be ____________________ to increase the ____________________. This task is carried out by _______________ from the _______________ The class of enzymes called ____________________ can then work to split the fats into _______________________ and ________________. This takes place in the ____________________ polysaccharides amylases monosaccharide s emulsified Surface area Bile salts liver lipases Fatty acids glycerol duodenum
- 31. 2c Enzyme action on proteins begins in the ________________. _________________ break the protein polymer into shorter chains _________________ then break the ____________________, setting free the amino acids. 3b A: liver – produces bile salts which emulsify fats B: pancreas 1)produced trypsin (which digests proteins), amylase (which digest starch), lipase (which digest fats) 2)Sodium bicarbonate present in the pancreatic juice neutralises the acid in chyme entering from the stomach and provides suitable pH for intestinal enzymes to work stomach proteases peptidases Peptide bonds