Digestion (B2.30-B2.34)
- Created by: Natasha Granville
- Created on: 11-05-16 17:22
View mindmap
- Mouth
- Oesophagus
- Stomach
- Small intestine
- Pancreas
- Large intestine
- undigested food passes into this wide, thin walled tube
- excess water diffuses back into the blood, leaving faeces
- faeces is stored in the rectum
- produces pancreatic juice
- which contains enzymes and neutralises stomach acid
- produces digestive enzymes
- and releases them into the small intestine
- Large intestine
- a long coiled muscular tube
- food is mixed with enzymes and bile
- digested food is absorbed into the blood by villi
- Pancreas
- churns food up with gastric juices by peristalsis
- hydrochloric acid kills bacteria
- enzyme pepsin starts the digestion of protein
- Small intestine
- muscular tube between the mouth and the stomach
- rhythmic contractions (peristalsis) moves food downwards
- Stomach
- food is chewed and mixed with saliva
- saliva lubricates food and makes it easier to swallow
- saliva contains amylase which begins the digestion of starch
- tongue rolls food into a bolus
- Oesophagus
- Anus
- undigested food (faeces) is passed out of the body
- Large intestine
- undigested food passes into this wide, thin walled tube
- excess water diffuses back into the blood, leaving faeces
- faeces is stored in the rectum
- protein
- protease, e.g. pepsin
- amino acids
- protease, e.g. pepsin
- fats
- lipase
- fatty acids
- glycerol
- lipase
- Bile
- alkaline, so neutralises stomach acid
- creates slightly alkaline environment for protease to work
- emulsifies fat
- breaks down large globules of fat into tiny droplets
- smaller globules have a larger surface area so lipase can break them down faster
- breaks down large globules of fat into tiny droplets
- stored in the gall bladder
- made in the liver
- alkaline, so neutralises stomach acid
- Villi
- increases the surface area of the small intestine
- so more diffusion can take place
- each villus has a good network of capillaries
- so there is a lower concentration of food molecules in the blood than in the small intestine
- so diffusion can occur along a steep concentration gradient
- so there is a lower concentration of food molecules in the blood than in the small intestine
- single layer of surface cells
- diffusion occurs more quickly as shorter distance
- increases the surface area of the small intestine
- functional foods- foods with health benefits
- Probiotics
- live, good bacteria
- found in gut
- e.g. Bifidobacteria and lactobacillus
- added to yogurt
- claim to make digestive system healthier
- and help to prevent disease and reduce allergies
- live, good bacteria
- Prebiotics
- carbohydrates that we can't digest
- e.g. oligosaccharides
- claim to help promote growth of good bacteria in gut
- helping digestive system and immune system
- Plant stanol esters
- found in plants
- used in foods like yogurts and spreads
- Probiotics
Comments
No comments have yet been made