4.4.2.3 Metabolism

Question 1

What is metabolism?

Answer 1

• sum of all chemical reactions in an organism

Question 2

What do many of the reactions in a cell do?

Answer 2

• link together to make a bigger reaction

Question 3

What are some examples of reactions that create larger molecules from smaller molecules?

Answer 3

• lots of small glucose molecules are joined together in reactions to form starch, glycogen and cellulose
• lipid molecules are each made from one molecule of glycerol and three fatty acids
• glucose is combined with nitrate ions to make amino acids, and then proteins

Question 4

What are some examples of reactions that break down larger molecules into smaller ones?

Answer 4

• glucose is broken down in respiration and transfers energy to power all reaction in body that make molecules
• excess protein is broken down in a reaction to produce urea, then is excreted in urine