Digestion And Absorption Flashcards
Why do large molecules need breaking down?
Too large to diffuse into cell
Cannot be absorbed into blood
What are proteins broken down into?
Amino acids
What are fats broken down into?
Fatty acids
Monoglycerides
What are carbohydrates broken into?
Monosaccharides
Which enzyme breaks down carbohydrates?
Amylase
Where is amylase produced?
Pancreas and small intestine
What does amylase hydrolyse?
Starch into maltose
What are membrane bound disaccharidases?
Enzymes attached to epithelium cell membrane of small intestine
Break down disaccharides into monosaccharides
How do monosaccharides pass through ileum membrane?
Active transport
Transporter proteins
How is fructose absorbed?
Facilitated diffusion
What are lipids broken down by?
Lipases and bile salts
What are lipids hydrolysed into?
Fatty acids and monoglycerides
Which bond is hydrolysed when breaking down lipids?
Ester bond
Where are bile salts made?
Liver
What do bile salts do?
Emulsify lipids to increase surface area for lipases
Once lipids are broken down, micelles are formed. What do micelles do?
Move monoglycerides and fatty acids to epithelium
How do fatty acids and monoglycerides pass through membrane?
Diffuse through bilayer
Which bond is broken in the hydrolysis of proteins?
Peptide bond
How are amino acids absorbed?
Active transport with sodium ions
What are endopeptidases?
Enzymes which break down bonds within a protein
What are exopeptidases?
Enzymes which break down bonds at the end of a protein and remove a single amino acid
Where are endopeptidases synthesised and secreted?
Made in pancreas
Secrets in small intestine
Give an example of an endopeptidase
Pepsin
What do exopeptidases work specifically on?
Hydrolysing peptide bonds in disaccharides
