Lesson on digestion of food

Hi,







I hope the 3 videos have helped you to understand:

-peristalsis, the wave-like rhythmic movement in the stomach and intestines to churn food and move food along the gut.

-mechanical digestion or chewing in the mouth. teeth break food into smaller particles

-chemical digestion or breaking down of food into smaller molecules so that they can be absorbed into the blood stream.

-producctionof of enzymes in mouth, amylase digests starch into maltose.

-production of enzyme pepsin and hydrochloric acid in the stomach. these help in the breakdown of proteins and kill germs in the food respectively.

-production of lipase and digestion of fats in the small intestine.

-villi in the small intestine to increase surface area in contact with digested food so that absorption is more efficient.

-absorption of digested food, small diffusible molecules into the blood stream.

-the circulatory system carries the food in the blood to all parts of the body for use or assimilation.

Cheers

Lesson 9: The digestive systems and enzymes

Hi,

Here are more powerpoint slides to revise the topic on digestion. The 30 slides cover the following concepts:

• annotated diagram of the alimentary canal
• ingest, digest, absorb, assimilate, egest
• deficiency diseases-scurvy, osteoporosis, rickets, night blindness
• balanced diet
• sources, functions of protein
• sources, functions of lipids
• sources, functions of carbohydrates
• sources, functions of minerals, vitamins, roughage, water
• foot tests-Biuret test, grease spot test, iodine solution test, Benedict's test
• teeth for mechanical digestion
• stomach for protein digestion
• small intestine-where all classes of food are digested completely
  
• liver-storage, process food, production of urea by deamination
• pancreas-production of digestive enzymes
• large intestine-absorption of water
• rectum-storage of bacteria, undigested food and roughage
• enzymes are biological catalysts
• proteases-in stomach and pancreatic juice
• carbohydrase-in mouth and pancreatic juice
• lipase-in pancreatic juice
• final products of digestion-amino acids, fatty acids and glycerol, glucose
• enzymes have active site, lower activation energy and are protein in nature
• biological enzymes are involved in bread and alcohol making by yeast cells, removing stains in clothes by washing powders
• absorption, villi, microvilli
• assimilation- glucose for respiration and storage as glycogen, amino acids for making proteins for growth, making enzymes, making hormones, fatty acids and glycerol for making cell membrane, hormones, storage under the skin
• obesity, diabetes, heart disease due to over eating
• short questions
  

The Digestive System

View more OpenOffice presentations from Dr samuel Aylward.

Cheers