Human Diet & Digestion

9.In which vessel would the concentration of fatty acids be highest after a meal?

10.Which of the following describe prevention methods for rickets?

11.A person has a condition that reduces the number of villi in the small intestine. What is the likely effect and explanation?

12.The graph shows the change in concentration of pathogens as food passes through the stomach. Which factor mainly explains the decrease?

13.Which of the following is not an example of physical digestion?

14.Where is bile produced?

15.The diagram shows a villus. Which labelled structure is the lacteal?

16.The diagram shows a tooth. Which part is the enamel?

17.Which enzyme breaks down starch?

18.What is the role of hydrochloric acid in the stomach?

19.A student tests a food sample with Benedict's solution and gets a brick-red precipitate. What does this indicate?

20.Which of the following correctly describes assimilation?

21.The graph shows the change in concentration of pathogens as food passes through the stomach. Which of the following is the main factor that explains the shape of the curve?

22.A student tests a food sample with Benedict's solution and obtains a brick-red precipitate. What does this indicate?

23.A smoothie contains soya protein, iron, fibre, low-fat milk, and water. Which ingredients are missing for it to be a balanced diet?

24.A student set up an experiment to investigate the effect of pH on the digestion of protein by pepsin. Four test tubes containing equal amounts of protein and pepsin were kept at different pH values. After 30 minutes, the amount of amino acids produced was measured. Which pH would produce the highest concentration of amino acids?

25.The table shows the energy content of four foods. Which food provides the most energy per gram?

26.A food sample gives a blue-black colour with iodine solution. Which food group is present?

27.A student set up an experiment to investigate the effect of pH on the digestion of protein by pepsin. Four test tubes containing equal amounts of protein and pepsin were placed in a water bath at 37°C. Each tube was buffered to a different pH. After 30 minutes, the amount of amino acids present was measured. Which pH would be expected to produce the greatest amount of amino acids?

28.A sample of food is tested with Benedict's solution and gives a blue colour. The same food is then boiled with dilute hydrochloric acid, neutralised, and tested again with Benedict's solution, giving a brick-red precipitate. What does this indicate?

29.Which of the following is the main factor that explains the decrease in pathogen concentration as food passes through the stomach?

30.In an experiment, a student placed equal volumes of starch solution and amylase solution in a beaker at 37°C. Every minute, a drop of the mixture was removed and tested with iodine solution. The blue-black colour disappeared after 5 minutes. If the experiment is repeated with amylase that was boiled for 10 minutes before adding, what result would be expected?

31.How does physical digestion help chemical digestion?

32.A student investigates the effect of pH on the digestion of protein by pepsin. Four test tubes each contain equal amounts of protein and pepsin at different pH values. After 30 minutes at 37°C, the amount of amino acid produced is measured. Which pH would produce the most amino acid?

33.The table shows the energy content of four foods. Which food provides the most energy per gram? Food Energy (kJ) per 100 g A 800 B 1200 C 1500 D 2000

34.A sample of food is tested with Benedict's solution and gives a blue colour. The same food is then boiled with dilute hydrochloric acid, neutralised, and tested again with Benedict's solution; this time it gives a brick-red precipitate. What does this indicate?

35.In an experiment, a student placed equal volumes of starch solution and amylase solution in a beaker at 37°C. Every minute, a drop of the mixture was removed and tested with iodine solution. After 5 minutes, the iodine remained orange-brown. What does this indicate?

36.The diagram shows a villus. Which labelled structure contains lymph and transports fatty acids and glycerol away from the small intestine?

37.The diagram shows a tooth. Which labelled part is the enamel?

38.A student set up an experiment to investigate the effect of pH on the digestion of protein by pepsin. Four test tubes containing equal amounts of protein and pepsin were adjusted to different pH values and kept at 37°C. After 30 minutes, the amount of amino acid produced was measured. The results are shown in the table. pH Amino acid produced (mg) 2 15 4 10 6 4 8 1 What is the optimum pH for pepsin?

39.The graph shows the change in concentration of pathogens as food passes through the stomach. Which of the following is the main factor that explains the decrease in pathogen concentration?

40.A smoothie contains soya protein, iron, fibre, low-fat milk, and water. What ingredients are missing from the smoothie for it to be a balanced diet product?