Enzymes and digestion

• enzymes are biological(protein) catalysts
• Catalyst: a substance that speeds up a reaction
• Enzymes lower the amount of energy needed for reaction to take place
• the lock and key theory

  
• substrate:the molecule before they are made to react
• product:the molecule that are made in a reaction
• catabolic reaction :molecules are broken down
• anabolic reaction : a reaction that builds up a molecule from smaller molecules
• enzymes have an optimum temperature :the temperature at which they work best giving the fastest reaction =37 C in animals
• when temperature increases ,molecules move faster so collie with an enzyme in less time
• having more energy makes enzymes more likely to bind to active site
• if temperature s too high ,enzyme molecules vibrate too vigorously and enzyme is denatured ;it loses its shape and will no longer bind with a substrate
• when the temperature is too low there is not enough kinetic energy for the enzyme reaction so it reacts too slowly
• some enzyme work best in an acid and others in a alkaline
• enzymes work best at their optimum pH
• if the pH is changed them the enzyme will denature and no longer fir with substrate- no reaction takes place
• a cell-the smallest unit of organisation within a living thing
• tissue- a group of specialised cells with a similar structure and function
• organ- a collection of different tissues working together to carry out specific functions
• organ system- a group of organs that work together to carry out specific functions and form organisms
• organism- a living thing
• digestion is the breaking down of big insoluble molecules into small soluble molecules
• bile is produced from the liver and stored in the gall bladder
• one reason why the stomach has acid is to kill bacteria and digest food
• starch _amylase breaks down carbohydrate into glucose(sugar)
• protein _protease_ breaks down proteins into amino acids
• lipids (fats)_lipase breaks down lipids into fatty acids and glycerol
• glucose solution (benedict's ),-test(blue),+test(brick red)
• starch solution(iodine),-test(Orange-brown),+test(blue-black)
• fats solution(ethanol),-test(clear ),+test(cloudy white)
• proteins solution(biuret),-test(blue), +test(lilac purple)
• if the digestion in your gut gets too hot the enzymes get denatured
• if the digestion in your gut gets too cold there is less kinetic energy therefore the particles move more slowly therefore fewer collisions per second between the substrate and the active site
• denatured -change in the shape of the active site of the enzyme
• metabolism all the chemical reactions in a living cell