Carbohydrates (2)

Question 1

Elements in a carbohydrate

Additional info: how is glucose formed

Answer 1

Carbon, hydrogen and oxygen

Additional info: glucose is formed when carbon dioxide and water react during photosynthesis in the presence of chlorophyll and sunlight

Question 2

Starch ->
Maltose ->
Lactose ->
Sucrose ->
Dietary fibre ->

Answer 2

Starch -> Glucose
Maltose -> Glucose + Glucose
Lactose -> Glucose + galactose
Sucrose -> Glucose + Fructose
Dietary fibre -> Dietary fibre

Question 3

Types of carbohydrates, definition and examples (1)

Answer 3

Simple carbohydrates
Monosaccharides -> Simplest unit of carbohydrates
-Glucose
-Galactose
-Fructose
Disaccharides -> Two units of monosaccharide bonded together
-Lactose
-Maltose
-Sucrose

Question 4

Types of carbohydrates, definition and examples (2)

Answer 4

Complex carbohydrates
Polysaccharides -> Made up of more than 10 units of monosaccharides bonded together
-Starch -> Consists of hundreds of glucose molecules joined together into a chain-like molecular structure [e.g. cereals (rice), tubers (potato or yam)]
-Dietary fibre
-Cellulose -> An insoluble component of cell walls that provides support to plants [e.g. fruits (apple), vegetables (carrot), whole grains (brown rice), beans (red bean)]
-Pectin ->A soluble component found in the cell walls of certain plants [e.g. fruits (lemon and grapefruit)]

Question 5

Functions of carbohydrates

Answer 5

1. Carbohydrates are one of the main sources of energy that fuels a person’s daily activities (1g carbohydrate -> 4 kilocalories of energy)
2. Carbohydrates in the form of dietary fibre provide bulk to stools, improve bowel movement and prevent constipation