Foods - The Digestive System - Weebly

The Digestive System

Home Functions Foods Tissue Types Essay

Food groups

Biochemical tests for different food groupsMethod:1. iodine test for starch-put a small amount of food sample into a spotting tile. add a few drops of iodine solution. if starch is present the mixture will turn brown/black colour.2. benedict's test for reducing sugar (glucose)- put a small amount of food sample into a test tube. add a few drops of benedict's solution until the sample is covered. put the test tube into a hot water bath and leave for a few minutes. if glucose is present the mixture will orange in colour.3. emulsion tests for lipids- put a small amount of the fat in a test tube and ad an equal amount of ethanol. shake the test tube gently. now add an equal amount of water. if it turns cloudy or fatty layer appears on the surface then lipids are present.4. biuret test for proteins- put a small amount of food in a test tube and add biuret solution. if the solution turns purple then protein is present.RESULTSsubstance StarchMarshmellow noOatabix yescheese nostarch yespasta yeswhole milk noglucose noraisin nothe above results are from the iodine test for starch. as shown, oatabix, starch and pasta all contain starch, compared to marshmellow, cheese, whole milk, glucose and raisins don't contain starch.substance sugarMarshmellow yesOatabix nocheese nostarch nopasta nowhole milk noglucose yesraisin yesthe above results are from the benedict's test for glucose. as you can see, only marshmellow, glucose and raisins contain sugar, whereas oatibix, cheese, starch, pasta and whole milk do not contain sugar.substance fatMarshmellow noOatabix yescheese yesstarch nopasta nowhole milk yesglucose noraisin noThe above results are from the emulsion test for lipids. as you can see, oatibix, cheese and whole all contain lipids, compared to the other which don't contain lipids.substance ProteinMarshmellow yesOatabix nocheese yesstarch nopasta nowhole milk noglucose noraisin nothe above results are from the biuret test for proteins. only marshmellow and cheese have proteins, whereas all oatibix, starch, pasta, whole milk, glucose and raisins don't contain protein. Biochemistry of the digestion goes as follows:Digestion breaks down our food into the constituent molecules. these molecules are the nutrients your cells need to survive, and they include:- carbohydrates*- proteins*- lipids*- nucleic acids*- vitamins*- water- minerals* - all with stars are all carbon based molecules Carbohydratesan example of carbohydrates is pasta, bread and rice. They are used to give us energy, but this energy is released over a long period of time meaning that it is a sloe release of energyproteinsan example of preoteins are read meat, fish and eggs. they are good for our body as they help our muscle cells grow and repair.lipidsan example of lipids are whole milk, cheese, and nuts. lipids have two main functions, the first being that it is a source of energy, and secondly, they insulate our bodies for climate/temperature change.vitaminsan example of vitamins are fruits and vegetables. vitamins are important, and lots of different vitamins, do different things for the body, for example vitamin D helps out body absorb calcium, which is good for our bones.Mineralsminerals are in most foods. yet the same as vitamins, they do different things to our body, for example iron, the mineral which our body uses for haemoglobin which carries blood around the body.waterwater is severely important, as the human body is around 60% water. chemical reactionsProtein - ----proteases ---->Amino Acids.Lipid ----- lipases ----> Glycerol and Fatty Acid.Starch ----- amylase ----> Sugar. Powered by Create your own unique website with customizable templates. Get Started