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After a meal rich in carbohydrates, the concentration of glucose in the small intestine changes - AQA - GCSE Biology - Question 7 - 2018 - Paper 1
Question 7
After a meal rich in carbohydrates, the concentration of glucose in the small intestine changes. Table 3 shows the concentration of glucose at different distances a... show full transcript
Worked Solution & Example Answer:After a meal rich in carbohydrates, the concentration of glucose in the small intestine changes - AQA - GCSE Biology - Question 7 - 2018 - Paper 1
Step 1
Step 2
Use the data in Table 3 to plot a bar chart on Figure 11.
Answer
To plot the bar chart:
- Label the y-axis as 'Concentration of Glucose (mol dm⁻³)'.
- Use a suitable scale, for example, 0 to 600 mol dm⁻³ to accommodate the highest concentration of 500 mol dm⁻³.
- Bar heights correspond to the concentrations at each distance (100 cm, 300 cm, 500 cm, 700 cm).
Step 3
Describe how the concentration of glucose changes as distance increases along the small intestine.
Answer
The concentration of glucose initially increases from 50 mol dm⁻³ at 100 cm to 500 mol dm⁻³ at 300 cm. After reaching the peak concentration at 300 cm, it then declines to 250 mol dm⁻³ at 500 cm and drops to 0 mol dm⁻³ by 700 cm.
Step 4
Explain why the concentration of glucose in the small intestine changes between 100 cm and 300 cm.
Answer
Between 100 cm and 300 cm, the concentration of glucose increases because carbohydrates are being broken down and absorbed into the bloodstream, leading to higher levels of glucose in this section of the intestine.
Step 5
Explain why the concentration of glucose in the small intestine changes between 300 cm and 700 cm.
Answer
From 300 cm to 700 cm, the concentration of glucose decreases because absorption is taking place. At 500 cm, the concentration is 250 mol dm⁻³, indicating that glucose is continually being absorbed, and by 700 cm, all glucose has been absorbed, resulting in 0 mol dm⁻³.