Biology - Chapter 7: Human Nutrition (Digestive tract)

What is the digestive juice and chemical process in the mouth cavity?

saliva, starch to maltose by salivary amylase

What is the physical process in the esophagus?

peristalsis

What is the physical process in the stomach?

churning

What is the chemical process in the stomach?

protein to peptide by pepsin

What is the digestive juice in the stomach and what is it?

Gastric juice, with hydrochloric acid, used to kill bacteria in food and provide optimum acidic pH for pepsin to work

What does the liver do?

produce bile

What does the gall bladder do?

store bile

What are the physical process in the small intestine?

peristalsis and emulsification

What are the digestive juices in the small intestine?

Intestinal juice, pancreatic juice, bile

Where are intestinal juices stored in?

glands in intestinal wall

What is the chemical process that comes with intestinal juice?

carbohydrate to monosaccharide by carbohydrase, protein to amino acid by protease

What is the chemical process that comes with pancreatic juice?

starch to maltose by pancreatic amylase, protein to amino acid by pancreatic protease, lipid to glycerol and fatty acid by lipase

How does emulsification works?

Bile turns fat into smaller oil droplets, which increases the surface area for lipase to work on, therby increasing the rate of lipid digestion

Which of the digestive juice is acidic?

gastric juice

What does physical digestion help in?

Increases the surface area for digestive enzymes to work on, thereby increasing the rate of chemical digestion

What does chemical digestion allow for?

for food subtances to pass through the intestinal wall for absorption

What is the overall process of human nutrition?

Ingestion > digestion > absorption > assimilation > egestion

Where does absorption mainly take place in?

ileum of the small intestine

During peristalsis, what happens?

circular muscles contract and longitudinal muscles relax. Lumen of alimentary canal becomes smaller to push food forward.