Topic 6 - Food and Digestion Flashcards
Balanced Diet
Where you intake food from different food groups in the correct proportions to get different essential nutrients
Digestion
The process by which large, insoluble food molecules are broken down into small, soluble food molecules
Mechanical digestion
The breakdown of food into smaller pieces without chemical change to the food molecules
Chemical digestion
When large insoluble molecules are broken down into small soluble molecules by the action of digestive enzymes
Enzyme
A biological catalyst that speeds up chemical reactions
Peristalsis
When circular and longitudinal muscles contract and relax to change the shape of the alimentary canal so food passes along
Absorption
When digested food molecules move from the digestive system into the bloodstream
Assimilation
The process by which the absorbed products of digestion are used to build new cells/parts of cells
Bile
An alkaline substance that creates optimum conditions for enzymes of the small intestine, neutralises the acidic bolus and breaks up large fat globules into smaller droplets (emulsification)
Egestion
The expulsion of the faeces through the anus
Ingestion
The consumption of a substance by an organism
Chemical elements present in carbohydrates
Carbon, hydrogen, oxygen
Chemical elements present in protein
Carbon, hydrogen, oxygen, nitrogen, sulfur
Chemical elements present in lipids
Carbon, hydrogen, oxygen
Carbohydrates structure
Starch is made of chains of glucose (polymer)
Protein structure
Protein is made of chains of amino acids
Lipids structure
Lipids are made of glycerol and three fatty acids
Test for starch
Yellow/orange iodine solution will turn blue-black
Test for glucose
Blue Benedict’s solution will turn green, then yellow, then orange or brick-red if there is a large amount of glucose