2.4 - adaptations for nutrition Flashcards
Autotroph
- An organism that creates complex molecules from simple molecules.
2 types of autotrophs + definition
- photoautotroph = uses light energy
-chemoautotroph = uses chemical energy
What are the 2 main nutrition methods of Animals ?
- heterotrophic- consuming other organisms
-holozoic - ingestion digestion, absorption and egestion
What is saparotrophic nutrition ?
Nutrition from dead/decaying organisms
- |extracellular digestion
Why is multicellular digestion less efficient than Animal digestion?
- ingestion + egestion occur at the same location
- Less enzymes
- Only 1 ph across whole system due to no different regions dor digestion
4 functions of the gut
INGESTION
DIGESTION
ABSORPTION
EGESTION
3 types of digestion
Mechanical digestion = teeth
chemical digestion (enzymes)
chemical digestion ( acid ph)
Outline the structure of the gut X4
Serosa = reduce friction
longitudinal muscle + circular muscle = rhythmic contractions , L = relax C= contract
Submucosa = remove absorption products + nerve transmissions
Mucosa = produce mucus to lubricate the food moving through the gut.
3 features of the buccal cavity
-HCO3 and co3 ions maintain ph7
-amalayse digests starch and glycogen into maltase
- mucus lubricates t he food for the passage down the oesophegus.
Outline the features of the stomach
- 2 sphincteers which contract to keep food in the stomach for several hours.
-stomach walls contract + mix with gastric juice.
-extra layer of muscle for more powerful contractions
What are the folds in the stomach wall called ?
Rugae
ZYMOGEN - gastric juice
- Zymogen secretes pepsinogen which is activated by H+ ions into pespin which is an endopeptidase.
Oxyntic cells - gastric juice
- oxyntic cells secrete HCL which lowers the Ph of the stomach
-optimum ph for enzymes
-kills majority of bacteria
-base of gastric pit
Goblet cells
- Goblet cells secrete mucus to lubricate food + protect stomach wall from enzymes
-top of gastric pit
Outline the components of bile
+purpose
- no enzymes
-bile salts which have hydrophobic and hydrophillic parts
-emulsifies lipids + lowers |SA
-Alkaline + neutralises food coming from the stomach.
Name the 4 enzymes in pancreatic juice
- Trypsinogen
-Endopeptidase
-Amalayse
-Lipase
Function of trypsinogen
trypsinogen is an inactive enzyme that is converted into trypsin - the endopeptidase by enterokinase .
Endopeptidase
Hydrolyses polyep[eptides into peptides
Role of NaCO3 in pancreatic juice
-neutralise acidic food from the stomach
What is the Crypt of Lieberkuhn ?
-contain brunners gland which produce mucus to lubricate and neutralise food from stomach.
- On the small intestine wall
4 Adaptation of the small intestestine
- contain villi + microvilli = increase SA
- capillary= maintian conc gradient
- Lacteal = absorb lipids
- epithelium = short diffusion
Define a Ruminant
- Group of herbivores possessing a stomach that is divided into 4 chambers.
Where is the Rumen and what is its function
In the gut of herbivores, where mutualistic microbes digest complex polysaccharides
Describe the 7 steps of cellulose digestion in herbivores -
- grass is cut by teeth + mixed with saliva to form cud.
- Enters the rumen where cellulose digesting microbes produce glucose.
-Glucose is fermented into organic acids and absorbed into the blood (produces methane + co2
-fermented grass passes into the reticulum where it is re-formed into cud - cud is regurgitated
-the absomasum digests protoens
-passes into small intestine
