Digestion Practice Questions

Define the term tissue.

The list shows four parts of the human body.

• glandular tissue in the wall of the stomach
• the digestive system
• a gland cell in the wall of the stomach
• the stomach

Write the four parts in order of size, starting with the smallest.

Name the organ system that transports the small soluble products of digestion around the body.

Name the reagent used to test for protein and give the colour change seen when protein is present.

Describe how the student should test the sample for sugars, and give the result she would see if sugars are present.

The student adds iodine reagent to a second sample of the food. The result shows that no starch is present.

Describe what the student saw.

Complete the table by giving one function in digestion for each organ.

Name the part of the digestive system where the digestion of starch begins.

Complete the table to show the substrate and the products of each digestive enzyme.

Name one organ that produces protease.

Name the type of molecule that all enzymes are made of.

Which molecule, P or Q, can be broken down by the enzyme in Figure 1?

Give a reason for your answer.

The enzyme is heated to $80\ ^{\circ}\text{C}$ and then cooled back to $37\ ^{\circ}\text{C}$. It can no longer break down molecule P.

Explain why.

Calculate the rate of starch digestion at $40\ ^{\circ}\text{C}$.

Use the equation:

$$\text{rate} = \frac{1}{\text{time}}$$

Give your answer in $\text{s}^{-1}$ to 3 significant figures.

Describe and explain the results between $10\ ^{\circ}\text{C}$ and $40\ ^{\circ}\text{C}$.

The student concluded that the optimum temperature for this amylase is $40\ ^{\circ}\text{C}$.

Suggest one improvement she could make to her investigation to find the optimum temperature more precisely.

Name the organ in which bile is made and the organ in which bile is stored.

Bile is alkaline.

Explain how this property of bile increases the rate at which lipids are broken down in the small intestine.

Explain how the student used the iodine reagent to decide that all the starch had been digested.

Explain why all the test tubes were kept in a water bath at $30\ ^{\circ}\text{C}$.

Give the optimum pH for this amylase shown by the results in Table 2. Explain your answer.

Name the process in cells that uses glucose to transfer energy.

Describe how the body uses the amino acids produced when the protein in the cheese is digested.

Explain why the starch in the bread must be digested before it can be used for respiration in cells.

Calculate how many times faster the reaction was in tube B than in tube A.

Explain the difference between the times recorded for tube A and tube B.

Explain why the student included tube C in the investigation.

A patient has a blocked pancreatic duct. This means that no pancreatic juice can pass from the pancreas into the small intestine.

Explain the effects that this will have on the digestion of the patient's food and on the substances available to the patient's body.

Give the optimum pH shown by the data for enzyme X and for enzyme Y.

Enzyme X is produced in the stomach. Use the data in Table 4 to explain why this is what you would expect.

Explain why the rate of digestion by enzyme Y decreases between pH 7 and pH 11.

A student concluded from Table 4 that the optimum pH of enzyme Y is exactly pH 7.

Evaluate this conclusion.