Human Diet And Digestion

9.Which of the following is a symptom of rickets?

10.Emulsification of fats is an example of chemical digestion.

11.The optimum pH for the enzyme pepsin in the stomach is approximately pH 2. What is the hydrogen ion concentration in mol/dm³ at this pH?

12.Name the process by which bile breaks down large fat droplets into smaller ones.

13.Which of the following is a symptom of scurvy?

14.Bile is produced in the gall bladder.

15.Which enzyme is produced in the mouth and the pancreas and digests starch?

16.Arrange the following stages of food breakdown in the correct order, starting from the first stage.

17.Which of the following are roles of bile? (Select all that apply)

18.Which of the following are roles of hydrochloric acid in the stomach? (Select all that apply)

19.Which of the following is an example of physical digestion?

20.Which of the following are produced in the pancreas? (Select all that apply)

21.Arrange the following in the correct order as food passes through the digestive system:

22.A student is investigating the effect of pH on the activity of the enzyme pepsin. At which pH would pepsin be most active?

23.Which of the following are roles of bile in digestion? (Select all that apply)

24.Match each enzyme to the food type it digests.

25.A student measures the pH of stomach contents as 1.5. What is the hydrogen ion concentration in mol/dm³?

26.A student is investigating the effect of pH on the activity of the enzyme pepsin. They set up test tubes with pepsin and protein solution at different pH values and measure the time taken for the protein to be digested. Which pH would result in the fastest digestion?

27.Emulsification of fats by bile is an example of chemical digestion.

28.Match each enzyme to the food substance it digests.

29.The diagram shows the human digestive system. Which labelled part produces bile?

30.Which food group is the main source of energy in a balanced diet?

31.Match each food group to its primary function in the body.

32.Bile is produced in the:

33.A student investigates the effect of pH on the activity of the enzyme pepsin. They set up four test tubes each containing pepsin and a protein solution at different pH values. After 10 minutes at 37°C, they measure the concentration of amino acids produced. The results are shown in the table: | pH | Amino acid concentration (g/dm³) | |----|----------------------------------| | 1 | 2.5 | | 2 | 4.8 | | 4 | 1.2 | | 7 | 0.1 | At which pH is pepsin most active?

34.A student sets up an experiment to investigate the effect of temperature on the digestion of starch by amylase. They add starch solution and amylase to test tubes at different temperatures and test for starch using iodine after 5 minutes. The results are shown in the table: | Temperature (°C) | Colour with iodine | |------------------|--------------------| | 10 | Blue-black | | 20 | Blue-black | | 30 | Brown | | 40 | Brown | | 50 | Blue-black | | 60 | Blue-black | At which temperature(s) was the starch completely digested?

35.In an experiment to investigate the effect of pH on the digestion of protein by pepsin, a student sets up four test tubes each containing pepsin and protein solution at different pH values. After 30 minutes at 37°C, the amount of digested protein is measured. Which pH is likely to show the greatest digestion?

36.Which of the following are roles of hydrochloric acid in the stomach? (Select all that apply.)

37.A student investigates the effect of temperature on the digestion of starch by amylase. They add starch solution and amylase to test tubes at different temperatures and test for starch using iodine after 10 minutes. At which temperature is starch most likely to be completely digested?

38.Which of the following are produced in the pancreas? (Select all that apply.)

39.Which of the following is a role of bile in digestion?

40.A student investigates the effect of pH on the digestion of protein by pepsin. Four test tubes each contain pepsin and protein solution at different pH values. After 10 minutes at 37°C, the amount of amino acid produced is measured. The results are shown in the table. | pH | Amino acid produced (mg) | |---|---| | 2.0 | 12.5 | | 4.0 | 8.2 | | 6.0 | 3.1 | | 8.0 | 0.5 | At which pH is pepsin most active?

41.Arrange the following stages of food breakdown in the correct order, starting from the first stage that occurs after food enters the mouth.

42.Complete the sentence about physical digestion.

43.State one function of hydrochloric acid in the stomach.

44.A student measures the pH of stomach contents as 1.5. What is the hydrogen ion concentration in mol/dm³? Give your answer to 3 significant figures.

45.A sample of stomach contents has a hydrogen ion concentration of 0.0316 mol/dm³. Calculate the pH of this sample. Give your answer to 2 decimal places.

46.Complete the sentence:

47.State two functions of hydrochloric acid in the stomach.

48.Complete the sentence about a balanced diet.

49.Complete the sentence about bile.

50.Explain why the stomach produces hydrochloric acid.

51.Describe how the structure of the small intestine is adapted for absorption of digested food.

52.A student measures the pH of stomach contents as 1.5. What is the hydrogen ion concentration in mol/dm³? Give your answer to 3 significant figures.

53.A sample of stomach contents has a hydrogen ion concentration of 0.0316 mol/dm³. Calculate the pH of this sample. Give your answer to 2 decimal places.