Q: A patient consumes a meal containing 60 g of glucose. If 45 g is absorbed into the bloodstream, what percentage of glucose was absorbed? Use the formula $$\left( \frac{\text{amount absorbed}}{\text{total amount}} \right) \times 100.$$

$$\left( \frac{45}{60} \right) \times 100 = 75\%$$

Q: If 18 g of glucose is absorbed in 3 hours, what is the rate of absorption? Use the formula $$\text{Rate} = \frac{\text{amount absorbed}}{\text{time}}.$$

$$\frac{18}{3} = 6\ \text{g}\ \text{h}^{-1}$$

Q: A solution's glucose concentration increases from 3.0 mmol dm$$^{-3} to 5.5 $$mmol dm$$^{-3} in 10 $$minutes. What is the rate of concentration change? Use $$\text{Rate} = \frac{\text{change in concentration}}{\text{time}}.$$

$$\frac{2.5}{10} = 0.25\ \text{mmol}\ \text{dm}^{-3}\ \text{min}^{-1}$$

Q: If 40 mg of product is formed in 20 minutes by an enzyme, what is the enzyme's rate of reaction? Use $$\text{Rate} = \frac{\text{product formed}}{\text{time}}.$$

$$\frac{40}{20} = 2\ \text{mg}\ \text{min}^{-1}$$

Question 1

A patient consumes a meal containing 60 g of glucose. If 45 g is absorbed into the bloodstream, what percentage of glucose was absorbed? Use the formula $$\left( \frac{	ext{amount absorbed}}{	ext{total amount}} ight) 	imes 100.$$

Accepted Answer

$$\left( \frac{45}{60} ight) 	imes 100 = 75\%$$

Question 2

If 18 g of glucose is absorbed in 3 hours, what is the rate of absorption? Use the formula $$	ext{Rate} = \frac{	ext{amount absorbed}}{	ext{time}}.$$

Accepted Answer

$$\frac{18}{3} = 6\ 	ext{g}\ 	ext{h}^{-1}$$

Question 3

A solution's glucose concentration increases from 3.0 mmol dm$$^{-3} to 5.5 $$mmol dm$$^{-3} in 10 $$minutes. What is the rate of concentration change? Use $$	ext{Rate} = \frac{	ext{change in concentration}}{	ext{time}}.$$

Accepted Answer

$$\frac{2.5}{10} = 0.25\ 	ext{mmol}\ 	ext{dm}^{-3}\ 	ext{min}^{-1}$$

Question 4

Which of the following factors would NOT directly increase the rate of nutrient absorption in the small intestine?

Accepted Answer

Decreased surface area of villi

Question 5

If 40 mg of product is formed in 20 minutes by an enzyme, what is the enzyme's rate of reaction? Use $$	ext{Rate} = \frac{	ext{product formed}}{	ext{time}}.$$

Accepted Answer

$$\frac{40}{20} = 2\ 	ext{mg}\ 	ext{min}^{-1}$$

Question 6

Which of the following would most likely decrease the rate of enzyme action in the human body?

Accepted Answer

A significant deviation from the enzyme's optimum pH

Question 7

A person eats a 120 g carbohydrate meal. After 75 minutes (with a 15-minute initial delay), the carbohydrate absorption rate is 2 mg/dl/min. How many grams of carbohydrate remain unabsorbed? Use the formula: $$	ext{Remaining unabsorbed carbs} = 	ext{Total carbs} - \left( \frac{	ext{Time elapsed} - 	ext{initial delay}}{	ext{Absorption rate}} ight).$$

Accepted Answer

$$120 - 30 = 90\ 	ext{g}$$

Question 8

Which enzyme would be most affected by a decrease in stomach acidity (higher pH)?

Accepted Answer

Pepsin

Question 9

If the surface area of the villi in the small intestine is reduced due to disease, what is the most likely effect?

Accepted Answer

Decreased rate of nutrient absorption

Question 10

A scientist increases the substrate concentration in an enzyme-catalyzed reaction. What will happen to the rate of reaction if the enzyme concentration remains constant and all active sites become occupied?

Accepted Answer

The rate will plateau and not increase further

Question 11

Which of the following best explains why pancreatic lipase works best in the small intestine?

Accepted Answer

Its optimum pH matches the alkaline environment of the small intestine

Question 12

A patient with celiac disease has damaged intestinal villi. Which of the following symptoms is most likely due to this damage?

Accepted Answer

Malnutrition due to poor nutrient absorption

Question 13

If the rate of enzyme action increases, what is the most direct effect on nutrient absorption?

Accepted Answer

Absorption rate increases due to more small molecules being available

Question 14

Which of the following scenarios would most likely result in a decreased rate of glucose absorption?

Accepted Answer

Damage to the intestinal lining

Question 15

A student calculates the rate of absorption as $$\frac{24}{4} = 6\ 	ext{g}\ 	ext{h}^{-1}. $$What does this value represent?

Accepted Answer

The amount of glucose absorbed per hour

Absorption Rates and Enzyme Activity in Digestion

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