B3-Digestion Flashcards
Test for starch
Add iodine solution to food and it should turn from a red yellow to a blue/ black
Test for sugar
Add Benedicte solution to cover food
Leave warm water bath 10minutes
Turns brick red when heated if glucose
Test for lipids(fat)
Few Drops ethanol to food
Shake and leave 1minute
Pour solution into a test tube of water
If ethanol creates cloudy white layer lipid is present
Test for protein
Add 1cm3 blue biuret or sodium hydroxide and copper sulfate solution
Turns purple if present
What are enzymes
are special proteins involved in ‘metabolism’ (reactions in the body) and help to speed up reactions. Some enzymes help build molecules, some break molecules down, others change one molecule into another.
What are digestive enzymes
break down food into smaller soluble molecules that can be absorbed into the bloodstream.
“Biological catalysts”
Carbohydrate (enzyme that breaks nutrient down, where and what are products)
Carbohydrase enzyme
Small intestine and mouth but also made in pancreas
Sugar
Proteins (enzyme that breaks nutrient down, where and what are products)
Protease enzyme
Produces by stomach, pancreas and small intestine and takes place in stomach and small intestine
Amnio acids
Fats (enzyme that breaks nutrient down, where and what are products)
Lipase enzyme
Made in pancreas and passed into the small intestine
Fatty acids and glycerol
What is bile
Made in liver but stored in gall bladder
Alkaline to neutralise hydrochloric acid from stomach
Emulsifies to form small droplets
Produces a large surface area for lipase to eat on
Turns large droplets-small droplets
Keeping the pH in your digestive system at optimum levels is difficult because
enzymes work best at different pH levels. So, your body creates a variety of different chemicals that help to keep conditions optimum for your enzymes.
As the temperature increases
reactivity increase as there is more kinetic energy so more random collision
but after their optimal temperature the protein structure is affected as the active site is affected so the substrate can no longer fit so it becomes denatured and is irreversible
Carbohydrates
All carbohydrates are made up of units of sugar.Some carbohydrates contain 1 unit of sugar e.g glucose. Other carbohydrates made up 2units of sugar (simple sugars) e.g, sugar. Complex carbohydrates have long chains of simple sugars bonded e.g. starch, cellulose. Carbohydrates provide us with energy for everything else and they contain hydrogen, carbon and oxygen. Rice, pasta, potatoes and rice are carbon rich foods. Carbohydrates we eat get broken down into glucose used in cellular respiration to provide energy for metabolic reactions in your cells
Lipids
Lipids are made up of three molecules of fatty acids joined to a molecule of glycerol which is always the same but the fatty acids vary in combination whether they will be a liquid oil or a solid fat. Lipids are fats and oils, most efficient energy store and important source of energy in your diet, combined other molecules are important in cell membranes as hormones in your nervous system and contain same as carbohydrates. Lipid rich food:oils e.g olive and sunflower oil, butter, margarine, cheese and cream
Proteins
Long chains of amnio acids 20 different ones of them joined by special bonds different arrangements various give different proteins. Have specific 3d shapes so other molecules can fit bonds can be broken easily. Act as:
-Structural components of tissues such as muscles and tendons
-Hormones such as insulin
-antibodies destroy pathogens part of immune system
-enzymes! act as catalyst
15-16 body mass is protein which found in tissues e.g. nails, hair, muscles,enzymes etc. Proteins are made up of carbon, hydrogen, oxygen and nitrogen. Protein rich foods:meat, fish, pulses and cheese