S3 Biology Chapter 5: Importance of Digestion

Play an AI-generated podcast conversation about this lesson

What is the primary reason for the necessity of digestion in the human body?

To regulate the absorption of vitamins and minerals

To break down large and complex food molecules into small, soluble molecules (correct)

To increase the surface area of food in contact with the digestive juices

To facilitate the mechanical digestion of food

What is the primary function of the digestive system?

To absorb and transport nutrients to the body cells (correct)

To convert nutrients into energy for body cells

To eliminate waste products from the body

To break down food into smaller, more complex substances

Which of the following molecules does not require digestion to be absorbed into the blood?

Vitamins (correct)

Lipids

Carbohydrates

Proteins

Which of the following organs is NOT a part of the digestive system?

Trachea (D) Signup and view all the answers

What is the role of mechanical digestion in the alimentary canal?

To increase the surface area of food in contact with the digestive juices (D) Signup and view all the answers

What is the function of bile salts in the small intestine?

To emulsify lipids (A) Signup and view all the answers

What is the role of digestive glands in the digestive system?

To produce digestive juices that help digest food (A) Signup and view all the answers

What is the difference between physical digestion and chemical digestion?

Physical digestion breaks down food into smaller pieces, while chemical digestion breaks down food into smaller molecules (A) Signup and view all the answers

What is the correct order of the alimentary canal?

Mouth, oesophagus, stomach, small intestine, large intestine (C) Signup and view all the answers

What is the role of digestive enzymes in chemical digestion?

To catalyze chemical reactions (D) Signup and view all the answers

Which of the following structures is responsible for producing bile?

Liver (A) Signup and view all the answers

What is the main function of the pancreatic duct?

To release digestive enzymes into the small intestine (D) Signup and view all the answers

What is the primary function of pancreatic amylase in the pancreatic juice?

To break down starch into maltose (D) Signup and view all the answers

What is the role of sodium hydrogencarbonate in the pancreatic juice and intestinal juice?

To provide an alkaline medium for the action of enzymes (B) Signup and view all the answers

What is the main function of proteases in the pancreatic juice?

To break down proteins into peptides and amino acids (B) Signup and view all the answers

What is the function of maltase in the small intestine?

To break down maltose into glucose (C) Signup and view all the answers

What is the main function of lipase in the pancreatic juice?

To break down lipids into fatty acids and glycerol (D) Signup and view all the answers

What is the pH of the intestinal juice?

Slightly alkaline (C) Signup and view all the answers

What is the primary function of the digestive process in human nutrition?

To break down food into simple molecules that can be transported in the circulatory system (A) Signup and view all the answers

Which of the following processes is responsible for the removal of undigested and unabsorbed materials from the body?

Egestion (D) Signup and view all the answers

What is the term for the process by which absorbed nutrients are taken up by body cells for metabolism?

Assimilation (C) Signup and view all the answers

In which process does food enter the bloodstream in the form of simple molecules?

Absorption (A) Signup and view all the answers

What is the correct order of the five main processes of nutrition in humans?

Ingestion, Digestion, Absorption, Assimilation, Egestion (C) Signup and view all the answers

What is the primary function of the absorption process in the small intestine?

To allow digested food substances to enter the bloodstream and be transported to body cells (B) Signup and view all the answers

What is the main difference between the functions of the small intestine and the large intestine?

The small intestine absorbs most of the nutrients, while the large intestine absorbs remaining water and electrolytes (B) Signup and view all the answers

What is the fate of the absorbed food substances in the bloodstream?

They are transported to body cells where they are used for energy and growth (B) Signup and view all the answers

What is the composition of the waste eliminated from the body through the anus?

Semi-solid waste containing undigested food substances and remaining water (A) Signup and view all the answers

What is the role of the blood capillaries in the absorption process?

To allow absorbed food substances to enter the bloodstream and be transported to body cells (D) Signup and view all the answers

What is the primary function of the large intestine in the digestive system?

To absorb remaining water and electrolytes, and eliminate waste (C) Signup and view all the answers