Question 1

What is absorption in the context of Exchange and Transport in Animals for Edexcel GCSE Combined Science?

Accepted Answer

Absorption in the context of Exchange and Transport in Animals refers to the process by which nutrients from digested food pass through the walls of the small intestine into the bloodstream. This process is crucial for distributing essential nutrients throughout the body to support cellular functions and overall health.

Question 2

How does the structure of the small intestine aid in absorption?

Accepted Answer

The small intestine is highly adapted for absorption due to its large surface area, which is increased by the presence of villi and microvilli. These structures provide a vast surface for nutrients to be absorbed efficiently. Additionally, the walls of the small intestine are thin and have a rich blood supply, facilitating the quick transfer of nutrients into the bloodstream.

Question 3

Why is absorption important for the human body?

Accepted Answer

Absorption is vital because it allows the body to obtain essential nutrients from food, which are necessary for energy production, growth, and repair of tissues. Without efficient absorption, the body would be unable to utilize the nutrients from food, leading to deficiencies and health issues.

Question 4

What role do villi play in the absorption process?

Accepted Answer

Villi are small, finger-like projections lining the small intestine that significantly increase its surface area, enhancing the absorption of nutrients. Each villus contains a network of capillaries and a lymph vessel called a lacteal, which transport absorbed nutrients, such as amino acids and glucose, into the bloodstream and lymphatic system, respectively.

Question 5

How does the absorption of nutrients differ between carbohydrates, proteins, and fats?

Accepted Answer

Carbohydrates are broken down into simple sugars like glucose, which are absorbed directly into the bloodstream. Proteins are digested into amino acids, which also enter the bloodstream through the capillaries in the villi. Fats, however, are emulsified and broken down into fatty acids and glycerol, which are absorbed into the lacteals of the villi and transported via the lymphatic system before entering the bloodstream.

Absorption

Practice questions

AI-marked quiz

Assess your understanding

Absorption — frequently asked questions