B7 Human Nutrition PDF

B7 Human nutrition  How would you define “a balanced diet”? A balanced diet consists of all of the food groups in the correct proportions Food groups Oesophagus, mouth, large intestine, small intestine, rectum, anusstomach 1 - mouth 2 - oesophagus 3 - stomach...

B7 Human nutrition  How would you define “a balanced diet”? A balanced diet consists of all of the food groups in the correct proportions Food groups Oesophagus, mouth, large intestine, small intestine, rectum, anusstomach 1 - mouth 2 - oesophagus 3 - stomach 4 - small intestine 5 - large intestine (colon) 6- anus 7 - rectum 8 - pancreas 10 - liver Digestion represents all the processes nutrients go through to be preapred for absorbtion. The function of the digestive system is to digest food and absorb nutrients. Some of the digestive system organs make up the alimentary canal; food passes directly through these organs as it moves through the body Some of the organs of the digestive system do not form part of the route travelled by food, but are still involved with digestion; these are the associated organs, or accessory organs  ingestion , mechanical digestion, chemical digestion, absorbtion, egestion, assimilation ingestion = food and drink are taken into the body through the mouth mechanical digestion = food is broken down into smaller pieces without chemical change to the food molecules chemical digestion = large, insoluble molecules are broken down into small, soluble molecules absorption = small food molecules and ions move through the wall of the intestine into the blood assimilation = food molecules from the blood are taken up by the cells of the body egestion = food that has not been digested or absorbed passes out of the body as faeces  Surface Area Volume Surface area to Volume ratio Physical digestion is the break down of food molecules (sometimes referred to as mechanical digestion) is the breakdown of food into smaller pieces without chemical change to the food molecules The processes that take place during physical digestion help to increase the surface area of food for the action of enzymes during chemical digestion Cells in the liver produce bile which is then stored in the gallbladder. It is alkaline to neutralise the hydrochloric acid which comes from the stomach. The enzymes in the small intestine have a higher (more alkaline) optimum pH than those in the stomach It breaks down large drops of fat into smaller ones. This is known as emulsification. The larger surface area allows lipase to chemically break down the lipid into glycerol and fatty acids faster. Chemical digestion is the breakdown of large insoluble molecules into small soluble molecules that can be absorbed Saliva Amylase Digest Starch  Gastric killing harmful acid microorganisms provide a acidic pH for pepsin to work Pepsin (protease) Digest proteins  Tripsin Digest proteins. (protease) Works in alkali conditions from the SI Amylase Digest starch into simple sugars Lipase Digests Fats