Digestion and Absorption Flashcards
What is the primary function of the digestive system?
To break down food molecules and absorb water.
What do digestive juices contain that facilitate digestion?
Hydrolytic enzymes and other molecules.
What is the process by which large insoluble food molecules are converted into smaller soluble molecules?
Hydrolysis.
What enzymes hydrolyse polypeptides and proteins into amino acids?
Proteases.
What enzymes are responsible for hydrolysing carbohydrates into simple sugars?
Carbohydrases.
Which enzymes hydrolyse fats into glycerol, fatty acids, and monoglycerides?
Lipases.
What enzyme do salivary glands secrete?
Salivary Amylase.
What is the role of gastric juice in the stomach?
It is acidic, kills microorganisms, and contains endopeptidases and exopeptidases.
Where does the majority of nutrient absorption occur?
In the small intestine (ileum).
What enzyme hydrolyses maltose to glucose in the small intestine?
Maltase.
Complete the sentence: In mammals, cellulose is NOT hydrolysed because _______.
the enzyme cellulase is not produced.
What are the products of starch digestion?
Maltose and glucose.
Which two types of enzymes are involved in protein digestion?
Endopeptidases and exopeptidases.
What is the function of dipeptidases?
To hydrolyse dipeptides into amino acids.
What type of transport do monosaccharides use to cross the epithelial cell membrane?
Facilitated diffusion and co-transport.
Describe the role of sodium ions in glucose absorption.
Sodium ions create a concentration gradient that facilitates glucose absorption.
True or False: Glucose absorption requires ATP directly.
False.
What is the role of bile in lipid digestion?
To emulsify fat droplets and increase the surface area for lipase action.
What are micelles and their function in lipid absorption?
Micelles make fatty acids soluble in water and transport them to the epithelial cell surface.
How are chylomicrons formed?
Triglycerides are modified and packaged with proteins at the Golgi apparatus.
What is the outcome of lipid digestion in the small intestine?
Lipids are hydrolysed into glycerol, fatty acids, and monoglycerides.
How are amino acids absorbed from the ileum into the blood?
By facilitated diffusion and co-transport using specific carrier proteins.
Fill in the blank: Proteins are hydrolysed by _______.
Proteases.
What happens to sodium ions if they are not actively transported out of the epithelial cell?
The concentration of sodium ions will rise in the cell.
