Biological Molecules

• What are the properties of water?

  Water is a dipolar molecule, which means that the oxygen has a slight negative charge at one end of the molecule, and each hydrogen has a slight positive charge at the other end. Hydrogen bonds are formed between the oxygen of one water molecule and the hydrogen of the other. As a result, water molecules have an attraction for each other otherwise known as cohesion, which is responsible for surface tension, letting aquatic insects like pond skaters to walk on pond surfaces.
• What are hydrophilic substances?

  Polar substances that can dissolve in water.
• What are hydrophobic substances?

  Non-polar substances that cannot dissolve in water.
• What is the term for the energy that is required to turn water from a liquid to a gas?

  High Latent Heat of vaporization
• What is the term for the large amount of energy required to increase the temperature of water?

  High specific heat capacity - This is due to the many hydrogen bonds in water molecules
• What are the properties of water's solid form?

  Ice is less dense than in its liquid form, meaning it floats on water. This insulates water below allowing organisms to survive in winter. This is due to ice's hexagonal structure which creates open spaces in between the molecule's.
• What is a Condensation reaction?

  A chemical reaction in which two molecules combine to form a larger molecule, with the simultaneous loss of a small molecule being water.
• What is a Hydrolysis reaction?

  Chemical reaction that breaks down a compound by reacting it with water.
• What are the Chemical Elements that make up biological molecules?

  Carbohydrates > Carbon (C) Hydrogen (H) Oxygen (O)

  Lipids > Carbon (C) Hydrogen (H) Oxygen (O)

  Proteins > Carbon (C) Hydrogen (H) Oxygen (O) Nitrogen (N) (Sulfur in cysteine)

  Nucleic Acids > Carbon (C) Hydrogen (H) Oxygen (O) Nitrogen (N) Phosphorus (P)