Section 2: Biological molecules

• Water is a reactant in lots of important chemical reactions, like hydrolysis or condensation
• Water is a solvent, meaning that some substances dissolve in it. Most biological reactions take place in solution.
• Water transports substances. The fact that it is a liquid and a solvent means that it can easily transport materials like glucose and oxygen.
• Water helps wirth temperature control because it has a high specific heat capacity and high latent heat of evaporation.
• Water is a habitat. The fact that it helps with temperature control, is a solvent and becomes less dense when it freezes.
• When frozen, ice forms an insulating layer so animals can live under the ice.
• what makes water a charged particle?

  Water is made of two positively charged hydrogen atoms and a negatively charged oxygen atom.
• what bonds are formed between water molecules

  Hydrogen bonds
• Why are hydrogen bonds between water molecules important?

  Cohesion and high heat capacity.
• what is specific heat capacity?

  The amount of heat energy required to raise the temperature of a substance by one degree Celsius.
• what is the specific latent heat of evaporation?

  Specific latent heat of evaporation is the amount of heat energy required to change a unit mass of a substance from liquid to gas at its boiling point.
• why is it good that water has a high specific heat capacity?

  Hydrogen bonds between water molecules can absorb lots of energy. This meas that water doesnt experience rapid temeperature changes, making the temperature in water relatively stable
• Why is it good that water has a high latent heat of evaporation?

  A lot of energy is needed to break hydrogen bonds that are in large concentration. This is useful for living organisms ebcause it means that water is great for cooling things, hence mammals sweat.
• Why do mammals sweat?

  It removes excess energy by the sweat evaporating on the surface of the skin, cooling the surface.