Topic 2

• Organells - cells - tissues - organs - organ system
• Tissue


  Group of similar cells working together to perform common function
• Organs


  Group of different tissues working together to perform common functions
• Catalyst


  A substance that increases the rate of reaction without being changed or used up in the process
• Enzymes are large proteins, so made from a long chain of amino acids
• Active site


  Part of the enzyme with a unique shape that is complementary to the substrate.
• Factors affecting enzymes

  • Temperature
  • PH
• High temperatures start to break the bonds holding the enzyme together This causes the enzyme and it's active site to change shape This means the enzymes active site will no longer be complementary to the substrate
• Carbohydrates provides us with energy for chemical reactions
• Lipids Provide energy for chemical reaction and store them to keep us warm or protect organs
• Proteins helps to grow, repair damaged tissues and can be used as emergency energy store
• Fibres helps food to move through intestines
• Lack of vitamin c can cause scurvy
• Iron is an important component of haemoglobin Haemoglobin is the protein in red blood cells that allows them to transport oxygen around the body A lack of iron (and hence haemoglobin), can lead to anaemia, where we can't transport enough oxygen to our tissues.
• Carbohydrates are made up of carbon, hydrogen and oxygen
• Carbohydrates are broken down by enzymes in mouth and small intestines.
• Monomers


  Small or single chain
• Polymers 


  Long chain or group of monomers
• Protein is made up of carbon, hydrogen, nitrogen and oxygen
• Enzymes in stomach and small intestine break protein into amino acids
• Lipids are made up

  Carbon, hydrogen and oxygen
• Lipids are breaked down in small intestines
• Lipids are made from a single glycerol molecule and three fatty acid molecules.
• Test for starch

  Iodine test
• Test for sugars

  Benedict test
• Test for protein

  Biuret Test
• Test for lipids

  Sudan III test
• What colour does the solution change to if starch is present

  Orange to blue-black
• Colour if protein is present

  Blue to purple
• Colour for benedict test

  Blue to bricky red