2.1 Metabolism & Water

Eastern collared lizards and pigs are two examples of animals that pant to keep cool.

Suggest how panting helps these animals to cool down.

[2 marks]

Methane is a product of the incomplete breakdown of dead organic matter. Methane can be seen bubbling out of the water in volcanic springs. 

Explain why, once methane has been produced, it bubbles off the water.

[2 marks]

Draw a labelled diagram showing cohesive forces between three water molecules.

[3 marks]

Outline the significance of the surface tension of water to living organisms.

[2 marks]

Using your knowledge of the properties of water, explain why dilute aqueous solutions (eg. glucose solution) are clear. 

[2 marks]

Explain the relationship between the osmolarity of a solution and its water potential. 

[3 marks]

Explain how water's high specific heat capacity helps to keep environmental conditions constant for organisms. 

[2 marks]

Water exists in all three of its physical states in Nature.

Give an example of each physical state of water that exists in Nature and how it affects organisms and ecosystems.

[6 marks]

Compare and contrast the properties of methane and water. 

[4 marks]

Explain why a methane molecule (CH₄) forms a tetrahedral shape.

[2 marks]

One mark is available for clarity of communication throughout this question.

Multiple pieces of evidence are required for scientists to falsify theories.

Discuss the evidence that scientists used to falsify the theory of vitalism.

[3 marks]

Deamination (the removal of an amino group from a molecule) and gluconeogenesis (the production of glucose from non-carbohydrate sources) are two reactions that occur in the liver.

From the information given, suggest with reasons, which metabolic reactions these are classified as.

[4 marks]

Explain the properties of water that are key for the survival of an oak tree.

[8 marks]