Digestion And Absorption Flashcards
What happens during digestion
Large biological molecules are hydrolysed to smaller molecules that can be absorbed across the cell membrane
Test for starch
Iodine
Positive- blue-black
Negative - orange- brown
Test for sugars
Benedict’s
Positive- brick-red
Negative - light blue
Test for proteins
Biuret
Positive- lilac -purple
Negative blue
Function of exopeptidase
Hydrolyse peptide bonds at end of polypeptide
Function of endopeptidase
Hydrolyse internal peptide bonds within polypeptide
Explain the digestion of lipids with in gut (exclude absorption)
Triglycerides decrease because of the action of lipase. They also decrease because of they are hydrolysed into fatty acids which causes the concentration of fatty acids to increases. They also decrease because of the digestion of the ester bonds.
Describe the role of micelles in the absorption of fats into the cells lining the ileum.
Micelles include bile salts and fatty acids
They make fatty acids more soluble in water
They bring the fatty acids to the lining of the ilium and releases it into cell
In calorimeter the higher the absorbency the darker/lighter the colour of the mixture
Darker the mixture
( it’s the absorbency of the substance rather than the absorbable on the other side)
A student did not have a colorimeter describe how a method this student could use to prepare colour standards and use them to give data for the total anthoyancic extracted
Use known concentration of pigment
Prepare dilution series
Compare results with colour standards to give concentration
What does bile do to fats
Emulsification
Where is amylase produced
Salivary glands
Pancreases
Small intestine
How does amylase work
It hydrolyses the polysaccharide into disaccharide by hydrolysing the glycosidic bond
not into monosaccharides because then the specific enzyme does it E,g. Maltase then digests monosaccharides maltose)
Enzyme that break down
Sucrose
Lactose
Maltose
Sucrase
Lactase
Maltase
Where does protein digestion start
Stomach
