Metabolism, anabolism and catabolismIB MYP Biology: Subtopic test

1. 1
   After a meal of rice and lentils in Mumbai, a student's body digests the food. Later her cells use some of the glucose to release energy, and use amino acids from the lentils to build new proteins for growth and repair.

   (a)

   What is meant by metabolism?

   [1 mark]

   • AAll the chemical reactions that take place in an organism
   • BOnly the reactions that release energy
   • CThe movement of food through the gut
   • DThe chemical reactions that happen only in plants

   (b)

   Which of these is an anabolic reaction?

   [1 mark]

   • ADigesting starch into glucose
   • BReleasing energy from glucose in respiration
   • CBuilding proteins from amino acids
   • DBreaking down fat into fatty acids

   (c)

   State whether digestion of the lentils and building new proteins are catabolic or anabolic, giving a reason for each.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A mango tree in Kerala, India, stands in bright sunshine. Its leaves make glucose, and all the living cells in the tree, including those in its roots, release energy from that glucose.

   (a)

   Which row classifies photosynthesis and respiration correctly?

   [1 mark]

   • APhotosynthesis is catabolic and respiration is anabolic
   • BBoth are anabolic
   • CBoth are catabolic
   • DPhotosynthesis is anabolic and respiration is catabolic

   (b)

   Which of these is NOT part of the tree's metabolism?

   [1 mark]

   • ARespiration in a root cell
   • BOxygen diffusing through the pores in the leaf
   • CPhotosynthesis in a leaf cell
   • DBuilding proteins in a growing shoot

   (c)

   Explain why photosynthesis is described as an anabolic reaction.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A student investigates how temperature affects the metabolism of woodlice, which are cold-blooded animals. She seals 10 woodlice in a respirometer tube containing soda lime, which absorbs carbon dioxide, and places it in a water bath. As the woodlice use oxygen, a drop of coloured liquid in a capillary tube moves towards them, and she measures how far it moves in 10 minutes. She repeats this at 10 °C, 20 °C and 30 °C, and the liquid moves 4 mm, 9 mm and 19 mm.

   (a)

   State a hypothesis for this investigation with a scientific reason, and name the independent and dependent variables.

   [3 marks]

   (b)

   Describe the trend in the results and evaluate the method.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A teenage footballer in São Paulo eats a protein-rich diet and trains every day to build muscle. His body digests the protein he eats, uses some of the amino acids to build new muscle protein, and respires glucose to release energy for training. Some athletes take anabolic steroids, which are drugs that speed up protein synthesis in muscle.

   (a)

   Explain what is meant by metabolism and describe how anabolic and catabolic reactions differ, using examples from the footballer's body.

   [6 marks]

   (b)

   Discuss and evaluate whether athletes should be allowed to use anabolic steroids.

   [6 marks]

   Total for question 4: 12 marks

End of questions