Biology a-level - Biological molecules

AQA flashcards in making

Monomers

Small units which make up large molecules

Polymers

Large molecules made up of many repeating small units joined together by chemical bonds.

Biological molecules VS Polymers

• Biological molecules are the large molecules (carbohydrates).

• Polymers are the specific type of biological molecule (starch, glycogen, cellulose).

Monomer EXAMPLES

• Monosaccharides

• amino acids

• nucleotides

Polymer EXAMPLES

• Protein

• Starch

• DNA

Carbohydrates

• carbon

• hydrogen

• oxygen

Lipids

• carbon

• hydrogen

• oxygen

Proteins

• carbon

• hydrogen

• oxygen

• nitrogen

Nucleic acids

• carbon

• hydrogen

• oxygen

• nitrogen

• phosphorous

Condensation reactions

The removal of water to form a chemical bond between two molecules. 

Hydrolysis reaction

The addition of water to break a chemical bond between two molecules. 

Carbohydrate general formula

C_x(H₂O)_y

Carbohydrates roles

1. Energy supply for cells (main role)

2. Energy store (sugar → complex carbs)

3. Structural components (cellulose + chitin in cell walls)

4. Cellular recognition - (Glycoproteins help cells identify each other and communicate. )

5. Building blocks for biological molecules - (Deoxyribose + ribose→ nucleic acids)

Types of carbohydrates

• Monosaccharide

• Disaccharide

• Polysaccharide

Monosaccharide EXAMPLES

• glucose

• fructose

• galactose

GFG - Get frickin good

Disaccharide EXAMPLES

• Maltose

• Sucrose

• Lactose

MSL - My silly lizard

Polysaccharide EXAMPLES

• starch

• glycogen

• cellulose