Digestion Flashcards
What is Digestion?
The process of breaking large insoluble molecules into small soluble molecules
Chemical Digestion
Food molecules are broken down by enzymes
Mechanical Digestion
Food is broken down into smaller pieces by chewing and churning in the stomach
Where is Bile produced and stored?
Made: Liver
Stored: Gall bladder
By what process do food molecules get absorbed in the small intestine?
Diffusion
How is the small intestine adapted for diffusion of nutrients to be rapid?
Lots of villi + microvilli -> Large surface area
Thin wall (one cell thick) -> Short diffusion distance
Good blood supply (from capillary network) -> maintains high concentration gradient
Ingestion
Taking in of food
Absorption
Nutrients pass through gut wall into blood
Assimilation
Getting rid of waste and undigested food
Peristalsis
Muscular contraction which squeezes food through the digestive sytem
Mouth structure
Teeth and Tongue
Mouth function
Mechanical digestion of food , moistens it
Salivary gland structure
Glands with ducts found in mouth
Salivary Glands Function
Produces saliva (contains amylase)
Digests starch -> maltose
Stomach structure
Muscular bag which produces HCl + protease enzymes + walls produce mucus
pH 2
Stomach function
Churns food into liquid chyme
Proteins digested into amino acids
Mucus stops stomach from being digested by HCl
Liver structure
Large organ/gland
Liver Function
Produces bile to emulsify fats
Pancreas structure
An elongated gland which contains islets of Langerhans (specialised cells)
Pancreas Function
Secretes pancreatic juice -> contains amylase, lipase, protease and hormones e.g. insulin
Small intestine Structure
Long muscular tube lines with villi + microvilli
Digests food using protease, lipase,
Small Intestine Function
Further digestion of food
Absorbs food and nutrients e.g. glucose into the blood
Large Intestine + Colon structure
Long muscular tube -> 1.5 m long
Large Intestine + Colon Function
Water further absorbed in colon
