Carbohydrates
Laura Armstrong & Joe Wolfensohn
Teachers


Recall Questions
This topic requires prior knowledge of monomers and polymers. You can test your knowledge on these below.
What is a monomer?
A small, single unit that can form larger polymers.
What are the monomers of carbohydrates?
Monosaccharides like glucose, galactose, and fructose.
What type of reaction joins monomers?
Condensation
What type of reaction breaks down polymers?
Hydrolysis
Topic Explainer Video
Check out this @JoeDoesBiology video that explains carbohydrates or read the full notes below. Once you've gone through the whole note, try out the practice questions!
What Are Carbohydrates?
- Biological molecules containing the elements: carbon, hydrogen, and oxygen.
- Provide energy, structural support, and aid cell recognition.
Types of Carbohydrates
1. Monosaccharides
- Examples: Glucose, Galactose, Fructose
- Function: Quick energy source.
- Properties: Soluble
2. Disaccharides
- Examples: Maltose, Sucrose, Lactose
- Function: Energy transport and storage.
- Properties: Soluble
3. Polysaccharides
- Examples: Starch, Glycogen, Cellulose
- Functions: Energy storage (starch in plants, glycogen in animals); structural support (cellulose in plants).
- Properties: Insoluble
Key Terms
- Condensation Reaction: Joins molecules, by making bonds and releasing water.
- Hydrolysis Reaction: Breaks bonds using water.
- Glycosidic Bond: The bond that links monosaccharides.
Contrast the structure of monosaccharides and polysaccharides (3 marks).
- Monosaccharides are individual monomers.
- Polysaccharides are made of many, repeating monosaccharides.
- Joined by glycosidic bonds.
- Formed in condensation reactions.
Practice Question
Try to answer the practice question from the TikTok on your own, then watch the video to see how well you did!