Nutrition D.1

Question 1

D.1.1. Outline the features of the principal components of the digestive system - mouth

Answer 1

mechanical and chemical digestion

Question 2

D.1.2 State the typical pH values found throughout the digestive system.

Answer 2

• Mouth: 5.5 - 7.5
• Stomach: 1.0 to less than 4.0
• Small intestine: 6.0 - 8.0
• Saliva: 6.5 - 7.5

Question 3

D.1.3. Describe the function of enzymes in the context of macronutrient digestion.

Answer 3

• Biological catalysts
• Helps speed up the process of digestion (by lowering activation energy required) → breaks down large food molecules into smaller ones so these can be absorbed

Question 4

D.1.4. Explain the need for enzymes in digestion

Answer 4

• Break down food so organisms can absorb it
• Increase the rate of digestion whilst maintaining a stable body temp

Question 5

D.1.5. List the enzymes that are responsible for the digestion of carbohydrates, fats and proteins from the mouth to the small intestine.

Answer 5

• Carbohydrates: salivary amylase, pancreatic amylase
• Fats: pancreatic lipase
• Bile: produced by the liver and is
  involved in the digestion of fat
• Proteins: pepsin, trypsin

Question 6

D.1.6. Describe the absorption of glucose, amino acids and fatty acids from the intestinal lumen to the capillary network.

Answer 6

Glucose, fatty acids and amino acids cross the brush-border membrane → pass through the cytosol of the absorptive cell → cross the basolateral membrane → entering the capillary network (glucose and amino acids) or the lymphatic system (fats)

Question 7

D.1.1. Outline the features of the principal components of the digestive system - esophagus

Answer 7

peristalsis action

Question 8

D.1.1. Outline the features of the principal components of the digestive system - stomach

Answer 8

rugae, lumen, mucous coating

Question 9

D.1.1. Outline the features of the principal components of the digestive system - small intestine

Answer 9

villi and microvilli increase area for absorption

Question 10

D.1.1. Outline the features of the principal components of the digestive system - large intestine

Answer 10

water balance, vitamin absorption

Question 11

D.1.1. Outline the features of the principal components of the digestive system - pancreas

Answer 11

production of enzymes

Question 12

D.1.1. Outline the features of the principal components of the digestive system - liver

Answer 12

production of bile

Question 13

D.1.1. Outline the features of the principal components of the digestive system - gallbladder

Answer 13

storage of bile