Unit 3 Food Studies - Digestion

What is the purpose of mechanical digestion?

• To break down food into smaller pieces

• To absorb nutrients into the bloodstream

• To neutralize stomach acid

• To produce digestive enzymes

Answer explanation

The purpose of mechanical digestion is to break down food into smaller pieces. This is so that the food is easier to process for the body and can be further broken down chemically in later stages of digestion. The other options, absorbing nutrients into the bloodstream, neutralizing stomach acid and producing digestive enzymes, are not the primary purpose of mechanical digestion.

Which enzyme is responsible for breaking down carbohydrates in the mouth?

• Salivary amylase

• Lingual lipase

• Pepsinogen

• Pancreatic amylase

Answer explanation

The enzyme responsible for breaking down carbohydrates in the mouth is Salivary amylase. This enzyme begins the digestive process by breaking down starch when you chew your food, converting it into maltose, a smaller carbohydrate. The other options, Lingual lipase, Pepsinogen, and Pancreatic amylase, function in fat digestion, protein digestion, and carbohydrate digestion in the small intestine, respectively.

What is the function of the stomach in digestion?

• To churn food with gastric juices to create chyme

• To absorb nutrients into the bloodstream

• To break down carbohydrates into glucose

• To produce bile for fat digestion

Answer explanation

The stomach's role in digestion is to churn food with gastric juices, forming a semi-liquid substance known as chyme. This process is crucial as it facilitates the further breakdown of nutrients in the small intestine. The other options, such as absorbing nutrients, breaking down carbohydrates into glucose, or producing bile, are not functions of the stomach, but are performed by other organs in the digestive system.

Where does the majority of chemical digestion occur?

• Mouth

• Oesophagus

• Stomach

• Small intestine

Answer explanation

The majority of chemical digestion occurs in the small intestine. This is where the final breakdown of food happens. The other options, mouth, oesophagus, and stomach, are involved in the initial stages of digestion but the small intestine is where the majority of it occurs.

What is the role of bile in digestion?

• To break down proteins into amino acids

• To neutralize stomach acid

• To emulsify fat for better digestion

• To absorb nutrients into the bloodstream

Answer explanation

Bile plays a crucial role in digestion, specifically in the emulsification of fats. It acts as a detergent, breaking down large fat globules into smaller ones, thus enhancing fat digestion. The other options, including breaking down proteins into amino acids, neutralizing stomach acid, and absorption of nutrients, are not functions of bile.

Which hormone controls the glucose level in the blood?

• Insulin

• Pepsinogen

• Lingual lipase

• Pancreatic amylase

Answer explanation

Insulin is the hormone that regulates glucose level in blood. It is produced by the pancreas and it allows cells to take in sugar (glucose) from the bloodstream to use as energy. Other options like Pepsinogen, Lingual lipase, and Pancreatic amylase are not directly related to the regulation of glucose levels.

Where does absorption of nutrients occur?

• Mouth

• Stomach

• Small intestine

• Large intestine

Answer explanation

The absorption of nutrients primarily occurs in the small intestine. This organ is specialized for this task with its villi and microvilli providing a large surface area for absorption. While other organs like the mouth, stomach and large intestine play a role in digestion, they are not the main site of nutrient absorption.

How is protein utilised by the body?

• Is a secondary source of energy

• Broken down into glucose

• To aid in enzyme, hormone and antibody production

• Growth, maintenance and repair of body cells

Answer explanation

Proteins play a crucial role in the body. They are not primarily used for energy, but instead are vital in the production of enzymes, hormones, and antibodies. However, their most significant function is to contribute to the growth, maintenance, and repair of body cells. Thus, the correct answer highlights the role of proteins in cell growth, maintenance, and repair.

Which enzyme is responsible for breaking down fats?

• Salivary amylase

• Protease

• Pancreatic lipase

• Pepsinogen

Answer explanation

The question asks about the enzyme responsible for breaking down fats. The correct answer is Pancreatic lipase. This enzyme is produced in the pancreas and plays a crucial role in the digestion of fats, converting them into fatty acids and glycerol. The options Salivary amylase, Protease, and Pepsinogen are incorrect as they are involved in the breakdown of other substances, not fats.

What are the main functions of fats in the body?

• To transport fat soluble vitamins

• To neutralize stomach acid

• To provide energy and insulation

• To absorb nutrients into the bloodstream

Answer explanation

The primary functions of fats in the body include the transport of fat-soluble vitamins, providing energy and insulation. They, however, do not neutralize stomach acid or directly absorb nutrients into the bloodstream. Fats provide a concentrated source of energy and provide padding to protect vital organs. They also promote proper function of nerves and the brain.