Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Digestion is the process of breaking down complex, insoluble food molecules into simple, soluble molecules like glucose () that the body can absorb.
The Alimentary Canal is a long muscular tube (approx. meters) consisting of the mouth, oesophagus, stomach, small intestine, large intestine, rectum, and anus.
In the mouth, Salivary Amylase breaks down starch into simpler sugars like Maltose.
The Stomach secretes Gastric Juice containing Hydrochloric Acid (), which provides an acidic medium and kills harmful bacteria.
The Liver secretes Bile, which is stored in the gall bladder and helps in the emulsification of fats.
The Pancreas secretes pancreatic juice containing enzymes such as Trypsin (for proteins), Lipase (for fats), and Amylase (for carbohydrates).
Absorption occurs primarily in the small intestine through finger-like projections called , which increase the surface area for better nutrient uptake.
Assimilation is the process where absorbed food is utilized by the body cells for energy, growth, and repair.
📐Formulae
💡Examples
Problem 1:
What is the function of in the human stomach?
Solution:
- It kills bacteria that enter with food. 2. It activates the enzyme Pepsin.
Explanation:
The stomach environment needs to be acidic (around ) for protein-digesting enzymes to function and to neutralize pathogens.
Problem 2:
Explain the role of Villi in the small intestine.
Solution:
Villi increase the surface area for absorption of digested food into the bloodstream.
Explanation:
By increasing the surface area, the rate of diffusion of nutrients like and amino acids into the capillaries is maximized.
Problem 3:
Identify the end products of fat digestion.
Solution:
Fatty Acids and Glycerol.
Explanation:
Under the action of the enzyme Lipase, complex lipid molecules are broken down into their constituent units: Fatty acids and Glycerol.