Carbohydrates, Lipids, Proteins

Question 1

Name a disease caused by deficiency of protein

Answer 1

Kwashiorkor

Question 2

Why do we need to eat food?

Answer 2

Because food provides us with
- energy for supporting daily activities
- energy for keeping us warm
- substances that are important for maintaining health

Question 3

Name the process /chemical reaction that forms disaccharides and polysaccharides.
Explain this chemical reaction.

Answer 3

Condensation
Two (monosaccharide) molecules combine with the loss of a water molecule.

Question 4

How do we convert disaccharides and polysaccharides back to monosaccharides?

Answer 4

Hydrolysis.
They are broken down into monosaccharides with a water molecule added.

Question 5

What are the characteristics of monosaccharides and disaccharides?

Answer 5

• are called sugars
• taste sweet
• are soluble in water
• they are all reducing sugars except sucrose

Question 6

Gives examples of monosaccharides and disaccharides and their sources, respectively.

Answer 6

monosaccharides : glucose, fructose, galactose
disaccharides : maltose, sucrose, lactose

Food sources
glucose and fructose : fruits and honey
galactose and lactose : milk, dairy products like cheese and yogurt
maltose : germinating barley
sucrose : sugar cane, sugar beet, table sugar

Question 7

What are the physical states of oils and fats, respectively ?
Where do they come from?

Answer 7

oils : liquid, from plants
fats : solid, from animals

Question 8

How many kilojoules (kJ) of each gram of lipids, carbohydrates, and proteins have?

Answer 8

Lipids : 38.9 kJ
Carbohydrates : 17.1 kJ
Proteins : 18.2 kJ