Water, ATP and Inorganic Ions Flashcards
Structure of water.
One oxygen atom and two hydrogen.
What makes water a polar molecule?
Slight positive charge of hydrogen atoms and slight negative charge of oxygen atoms. Bonds other water molecules together with hydrogen bonds also.
How is water an important metabolite?
It breaks bonds in hydrolysis reactions and is releases in condensation reactions when a new bond is formed.
What does high latent heat of vaporisation mean and why is it a useful property in water?
A lot of energy is required to break the hydrogen bonds between water molecules meaning a lot of energy is used when water evaporates. This is useful for cooling the body by using water loss through evaporation to cool down.
How can water act as a buffer?
Hydrogen bonds absorb a lot of energy so water has an high specific heat capacity (takes a lot of energy to heat up) which is useful for making water a good habitat as it doesn’t experience rapid temperature change and it good for maintaining a constant internal body temperature.
How is water a good solvent?
Being polar the positive end attracts to negative ions and the negative end attracts to positive ions meaning water molecules can totally surround ions dissolving them.
Describe how water molecules are cohesive.
Very cohesive because they are polar, this helps with water flow making them good for transport (xylem) and also creates high surface tension.
What is the function of ATP?
Immediate source of energy, energy from glucose used to make ATP which diffuses to the park of the cell that needs energy.
Structure of ATP.
Adenine, ribose sugar and three phosphates.
Where is the energy in ATP stored?
In high energy phosphate bonds between phosphate groups - released in hydrolysis.
Describe how energy is released from ATP.
ATP is broken down into ADP and and inorganic phosphate (Pi) in a hydrolysis reaction where a phosphate bond is broken releasing energy, catalysed by ATP hydrolase.
Describe how ATP can be re-synthesised.
Condensation reaction between ADP and Pi catalysed by ATP synthase.
What is an inorganic ion?
An electrically charged atom that doesn’t contain carbon.
Why are iron ions important?
The four polypeptide chains in haemoglobin each contain an iron ion which binds to the oxygen in haemoglobin.
Why are hydrogen ions important?
They determine pH - the higher the concentration of H ions, the lower the pH (more acidic).
