GCSE Double Award Science - Biology Unit 1: Nutrition and Food Tests

These flashcards cover the critical concepts related to nutrition and food tests from the Biology Unit 1 lecture notes.

What are the three main elements found in carbohydrates, proteins, and fats?

Carbon, hydrogen, and oxygen.

Which element is exclusively found in proteins?

Nitrogen.

What are the main sources of carbohydrates?

Simple sugars are found in biscuits and cakes; starch is found in potatoes, rice, pasta, and bread.

What is the primary reason why we need protein in our diet?

Growth and repair.

What are the two types of carbohydrates?

Simple carbohydrates (sugars) and complex carbohydrates (starch, glycogen, cellulose).

What is the storage carbohydrate in plants?

Starch.

What happens to carbohydrates during digestion?

They are broken down into glucose.

What two biological molecules are our main sources of energy?

Carbohydrate and fat.

What type of fat is known for being an excellent energy source?

Lipids.

What is cellulose and why is it important in our diet?

It is found in plant cell walls and provides fiber, helping to push food through the digestive system.

What is the method to test for starch in food samples?

Add iodine solution to the food; it changes from yellow-brown to blue-black if starch is present.

How does Benedict's test work for reducing sugars?

Add Benedict's solution to the food and heat; it changes from blue to green, orange, or brick red if reducing sugars are present.

What is produced when fats are broken down?

1 glycerol and 3 fatty acids.

What method is used to investigate the energy content of food?

Burning food samples and measuring the change in water temperature.

What do amino acids link together to form?

Proteins.

Which food type contains double the energy per gram compared to carbohydrates and proteins?

Fats/Lipids.

Why is starch important for energy release?

It releases energy more slowly than simple sugars.

What change indicates that protein is present in a food sample using Biuret test?

The solution changes from blue to lilac/purple.

What are the sources of protein?

Lean meat, beans, fish, and egg white.

What is the primary function of carbohydrates in our diet?

To provide energy.

What are the key components of a balanced diet?

Carbohydrates, protein, fats/lipids, vitamins and minerals, fiber, and water.

Which test makes a white emulsion indicating the presence of fats?

Ethanol test.

What is the role of cellulose in our diet?

To add fiber which helps in digestion.