Unit 4A.1 | Topic 1 | Biochemistry | Quiz

Which of the following are the three main macronutrients required by the body?

• Vitamins, minerals, water

• Carbohydrates, proteins, fats

• Fibre, water, proteins

• Enzymes, lipids, carbohydrates

Answer explanation

The three main macronutrients required by the body are carbohydrates, proteins, and fats. These nutrients provide energy and are essential for growth, metabolism, and overall health.

Why do carbohydrates provide a more immediate source of energy than fats?

• Fats are absorbed faster than carbohydrates

• Carbohydrates are quickly broken down into glucose

• Proteins help digest fats faster

• Fats have more energy than carbohydrates

Answer explanation

Carbohydrates provide a more immediate source of energy because they are quickly broken down into glucose, which the body can readily use for energy, unlike fats that take longer to metabolize.

What reagent is used to test for the presence of starch in food?

• Iodine solution

• Benedict’s solution

• Biuret solution

• Sudan III

Answer explanation

Iodine solution is used to test for starch. When iodine comes into contact with starch, it forms a blue-black complex, indicating the presence of starch in the food sample.

Why does an apple provide more energy than celery?

• Apples contain more fibre than celery

• Celery contains more proteins than apples

• Apples have a higher sugar content

• Celery has more vitamins than apples

Answer explanation

Apples provide more energy than celery primarily because they have a higher sugar content. Sugars are a quick source of energy, while celery has lower sugar levels and is more water-dense, contributing less energy overall.

Which statement best evaluates the idea that "all fats are bad for you"?

• Some fats, such as unsaturated fats, are beneficial for heart health

• All fats increase cholesterol levels equally

• Fats are unnecessary in the human diet

• Only trans fats are unhealthy

Answer explanation

The statement "Some fats, such as unsaturated fats, are beneficial for heart health" correctly counters the idea that all fats are bad, highlighting that certain fats can actually promote health.

Which of the following meals is best suited for an athlete needing quick energy?

• A steak with buttered vegetables

• A banana with oatmeal and peanut butter

• A large salad with water

• A protein shake with no carbohydrates

Answer explanation

A banana with oatmeal and peanut butter provides quick-digesting carbohydrates and healthy fats, making it ideal for athletes needing immediate energy. Other options lack the necessary quick energy sources.

Match the following descriptions with their roles in digestion.

• Role of enzymes in digestion

• They transport nutrients through the bloodstream

• Function of the liver

• They break down food molecules into smaller components

• Function of fat cells

• They remove toxins from the body

• Role of blood vessels

• They store energy for later use

Answer explanation

Enzymes play a crucial role in digestion by breaking down food molecules into smaller components, making it easier for the body to absorb nutrients. This distinguishes them from other functions like energy storage or toxin removal.

What process forms a disaccharide like sucrose?

• Hydrolysis

• Dehydration synthesis

• Oxidation

• Reduction

Answer explanation

Disaccharides like sucrose are formed through dehydration synthesis, a process where two monosaccharides combine, releasing a water molecule. This reaction creates a glycosidic bond, linking the sugar units together.

Benedict’s solution is used to test for the presence of: (a)  

• Reducing sugars
• Proteins
• Lipids
• Starch

Answer explanation

Benedict's solution is specifically used to test for reducing sugars, which can donate electrons and reduce copper ions in the solution, leading to a color change. It does not test for proteins, lipids, or starch.

What is the main difference between amylase, lipase, and protease?

• Amylase digests lipids, protease digests carbohydrates, lipase digests proteins

• Amylase digests carbohydrates, lipase digests fats, protease digests proteins

• Lipase digests carbohydrates, protease digests fats, amylase digests proteins

• All enzymes perform the same function

Answer explanation

Amylase breaks down carbohydrates, lipase breaks down fats, and protease breaks down proteins. The correct choice accurately describes the specific functions of each enzyme.