Digestion Flashcards
State what happens in digestion.
Large molecules are broken down into smaller molecules that pass into the blood.
Name the structure that food passes along to reach the stomach.
Oesophagus.
Describe how food moves along the gut.
Muscles in the wall of the gut squeeze food along.
Explain how the villi in the small intestine are adapted to help absorb nutrients into the blood.
The villi have a large surface area and thin walls to absorb more nutrients and contain blood capillaries to carry away the absorbed food molecules.
State three problems caused by being underweight.
Poor immune system, often tired, likely to suffer from a lack of vitamins and minerals.
State three diseases obese people have an increased risk of.
Heart disease, stroke, diabetes, some cancers.
Describe the role of lipids in the body.
Provide a store of energy, keep you warm, protect organs (e.g. kidney and heart) from damage.
Name the nutrient used for growth and repair.
Protein
Explain what is meant by a balanced diet.
Eating food containing the right nutrients in the correct amounts.
Explain the difference between simple and complex carbohydrates.
Simple carbohydrates (e.g. sugars) provide a quick source of energy. Complex carbohydrate (starch) need to be digested so the energy is released more slowly.
What is the food test and positive result for starch?
Starch turns iodine blue-black.
What is the food test and positive result for sugar?
Sugar turns Benedict’s solution orange-red when placed in a water bath.
What is the food test and positive result for protein?
Protein turns Biuret solution purple.
What is the food test and positive result for fat?
Fat makes filter paper transparent.
State the unit that energy in food is measured in.
Joules (J)
