Digestion And Absoption Flashcards
(14 cards)
Digestion definition
The process of breaking down food into substances that can be used by the body
What enzyme is used in breakdown of starch
Amalyse
How does amylase work
Catalysing hydrolysis reactions that break the glycosidic bonds in starch to produce maltose
Where is amylase produced
Salivary glands then released into the mouth
Pancreas then released into small intestine
What are membrane-bound disaccharides
Extend that are attached to the cell membranes of epithelial cells lining the ileum
They help break down disaccharides into monosaccharides
Three disaccharides
Sucrose
Maltose
Lactose
Three disaccharidases
Sucrase
Maltase
Lactase
Monosaccharides
Glucose + glucose = maltose
Glucose + fructose = sucrose
Glucose + galactose = lactose
What enzyme breaks down lipids
Lipase enzymes
Involves the hydrolysis of Ester bonds
What are endopeptidases
An enzyme that breaks peptide bonds in between the amino acids in the middle of the polypeptide chains
What are exopeptidases
An enzyme that breaks the peptide bonds at the end of the polypeptide chain
Absorption of monosaccharides
Glucose absorbed by active transport with sodium ions via a co transporter protein
Galactose absorbed in the same way
Fructose is absorbed via facilitated diffusion through a different transporter protein
How monoglycerides and fatty acids are absorbed
Micelles help move monoglycerides and fatty acids towards the epithelium
Monoglycerides and fatty acids are lipid soluble so can diffuse directly across the epithelial cell membrane
How amino acids are absorbed
Similar way to glucose and galactose
Sodium ions actively transported out of the epithelial cells into the ileum
They diffuse back into the cells through sodium depended transporter proteins carrying the amino acids with them
