Enzyme
Which enzyme begins the digestion of starch in the mouth?
Enzymes catalyse the breakdown of large, insoluble food molecules into smaller, soluble molecules that can be absorbed.
Where is bile produced?
Liver
What is the main function of the small intestine?
digestion and absorption of nutrients.
What is the main function of carbohydrates?
They provide energy for respiration.
What is ingestion?
The process of taking food into the mouth.
Which enzyme begins the digestion of starch in the mouth?
Amylase
Where is bile released?
Small intestine
How are villi adapted for absorption?
Villi provide a large surface area for absorption.
Which nutrient is needed for healthy bones and teeth?
Calcium/ Vitamin D
Which structure in the small intestine is adapted for absorption?
Villi and microvilli.
Which enzyme breaks down lipids? and what are the products?
Lipase breaks down lipids into fatty acids and glycerol.
What is the main role of bile in lipid digestion?
Bile emulsifies lipids, breaking large fat droplets into smaller droplets.
Why is the wall of the small intestine only one cell thick?
It provides a short diffusion distance, allowing nutrients to pass quickly into the blood.
What is a balanced diet?
A diet that provides all 7 nutrients the body needs in the correct proportions.
What is absorption?
The movement of small, soluble nutrients from the small intestine into the blood or lymph.
What is the role of enzymes in digestion?
Enzymes catalyse the breakdown of large, insoluble food molecules into smaller, soluble molecules that can be absorbed
Why is neutralisation important for digestion in the small intestine?
It provides a suitable pH for intestinal and pancreatic enzymes to work effectively.
What is the role of the lacteal in a villus?
absorbs and transports fatty acids and glycerol
Why is iron important in the diet?
Iron is needed to make haemoglobin, which carries oxygen in red blood cells.
What is the difference between egestion and excretion?
Egestion removes undigested food, while excretion removes metabolic waste products such as carbon dioxide and urea.
Why does pepsin work well in the stomach?
The stomach contains hydrochloric acid, which provides the low pH required for pepsin to work effectively.
Does bile chemically digest lipids?
No. Bile physically emulsifies lipids; breaking large fat droplets into smaller droplets.
Why is the small intestine long?
Its long length provides a large area and sufficient time for digestion and absorption.
Why is water important to the human body?
Water is needed for chemical reactions, transport of substances, and temperature regulation.
What are the five stages of nutrition in humans in the correct order?
Ingestion → Digestion → Absorption → Assimilation → Egestion