Core Concepts: Carbohydrates

What are the **functions** of carbohydrates?

1. **Instant energy sources**
2. **Transportable/Storable energy sources**
3. **Structural Materials**

What is a **monosaccharide**?

**monomers** - single sugars named according to the number of carbon atoms in the molecule

What is the general formula for monosaccharides?

C(H²O)n

What is a triose sugar?

A **triose** is a monosaccharide containing three carbon atoms.

Give an example of a triose sugar

Glyceraldehyde 

What is a pentose sugar?

A pentose is a monosaccharide with five carbon atoms.

Give an example of a pentose sugar

Ribose (*found in RNA*)

What is a hexose sugar?

A hexose is a monosaccharide with six carbon atoms.

Give an example of a hexose sugar

Glucose

What are **isomers**?

Molecules with the **same molecular formula** but with **different arrangements** of their atoms are called **structural isomers**

Give an example of **2** types of isomer

* Alpha and Beta Isomers
* Ring and Straight Chain Isomers

What does **ABBA** stand for?

*Alpha -* Below

*Beta -* Above

Which monosaccharide is this?

Fructose

Which monosaccharide is this?

Galactose

Glucose is the **major**…?

**Respiratory substrate** which is broken down to make ATP

Where is alpha glucose found?

blood plasma

Where is beta glucose found?

In plants

Where is fructose found?

Fruits

Where is galactose found?

Milk

What happens in a **condensation** reaction?

* A water molecule is **removed**
* A new **covalent bond** is formed
* **Larger molecules** are formed

What happens in a **hydrolysis** reaction?

* A water molecule is **added**
* A **covalent** bond is **broken**
* A **smaller** molecule is formed

What is a **disaccharide?**

**2 monosaccharides** can join together through a **condensation reaction** to form a **disaccharide**

When a condensation reaction between 2 **alpha glucose** molecules occur, what is the product?

maltose

Which 2 monosaccharides join to form **sucrose**?

Glucose +Frutose

Which 2 monosaccharides join to form **lactose**?

Glucose +Galactose

What is a **polysaccharide**?

A **polymer** made of **many** glucose molecules linked together.

What is the **storage polysaccharide** found in **animals**?

Glycogen

What is the **storage polysaccharide** found in **plants**?

Starch

What is the **structural polysaccharide** found in **plant cell walls**?

Cellulose

What **4 components** make polysaccharides ideal for storage?

* No osmotic effect
* Compact
* Glucose can easily be **added** or **removed** by hydrolysis or condensation
* Insoluble

What two polymers make up **starch?**

Amylose + Amylopectin

What is **amylose**?

Polymer of alpha glucose joined by 1,4 **glycosidic chains** to form **coiled chains**

What is **amylopectin**?

**branched polymer** - links between **carbon 1 and 6**

What is **glycogen?**

* Polymer of alpha glucose joined by **1,4 glycosidic links** to form coiled chains
* Many side chains are linked by **1,6 glycosidic links**

Where is **glycogen** stored?

as **glycogen granules** in the @@liver and muscle cells@@

Which is more compact, **glycogen** or **starch**?

Glycogen

What is **cellulose?**

* An **insoluble** polysaccharide made from long, straight chains of **beta glucose**
* **Joined by Beta glucose** 1,4 chains
* Each molecule is rotated 180 degrees

The **structure** of cellulose is in a ….

Microfibril - makes it very strong

**True/False:** Most organisms cannot digest/hydrolyse cellulose

**True**

Give a function of cellulose in the cell wall

Prevents the cell wall from bursting when the cell becomes turgid

What is chitin?

A **structural** carbohydrate found in the **exoskeletons of insects** and the **cell walls of fungi**

What is the main difference between the structure of **chitin** compared to **cellulose**?

Chitin has an **acetyl amide** group (CH3CONH2)

Give three features of **chitin**

* Strong
* Waterproof
* *Light for flight*

**True/False:** Cellulose microfibrils have more tensile strength than chitin microfibrils

**False** - Chitin microfibrils have greater tensile strength than those of cellulose due to having more N groups which helps form more hydrogen bonds