ATP is a nucleotide derivative used by the body to provide energy. The structure of ATP is shown below.

Circle the adenine base on the ATP molecule.

Name the other two components of an ATP molecule.

Describe how ATP is broken down to release energy.

Describe two ways in which ATP is a suitable energy source in living organisms.

Water is the major component of many living organisms and its properties allow it to carry out numerous functions within cells. 

Name the type of chemical reaction in which a water molecule is used to breakdown a dimer.

A body of water consists of many hydrogen bonds. Explain how hydrogen bonding occurs between water molecules.

Water is used as a transport medium within living organisms. Explain how the properties of water allow it to carry out this function.

Explain four other properties that make water important for organisms.

Water and inorganic ions have important biological functions inside cells.

The diagram below shows two molecules of water. Draw and label a bond between the two molecules.

Explain the property of water that allows it to minimise large fluctuations in temperature.

Explain how the density of water allows organisms to use it as a habitat.

Describe the roles of the inorganic ions iron, sodium, and phosphate ions within organisms. 

Inorganic ions, ATP, and water are essential molecules required for many biological processes. 

One example of an anion used by many living organisms is phosphate. This is used in the synthesis of ATP and nucleic acids. Other than phosphate, name one anion and give an example of its importance within organisms.

Describe how a molecule of ATP is synthesised from ADP and inorganic phosphate. 

Name three examples of biological processes that require ATP.

State and explain the property of water that allows organisms to cool down using evaporation.

A student investigated the effect of pH on the activity of ATP synthase. She used the production of ATP in isolated chloroplasts. She prepared four test tubes A, B, C, and D and added isolated chloroplasts of the same concentration to each test tube.

She then added buffer solutions with different pH levels to the four test tubes and incubated them in the presence of light for 10 minutes. She then measured the amount of ATP produced in each test tube using a colorimeter. 

Her results are shown below. 

Other than those given, name two variables the student should have controlled.

Describe the trend shown in the table.

Why did she add buffer solutions to each test tube?

Suggest why she incubated the test tubes in the presence of light.