Enzymes 1 specific 2 carbohydrates 3 starch 4 protease 5 break down substrate products Enzymes are 1……….. to one reaction. Carbohydrase enzyme breaks down 2…………………… Amylase is a carbohydrase which breaks down 3………………. 4…………….. enzymes break down proteins. Lipase enzymes 5………………….. fats. 2 carbohydrates 3 starch 4 protease 5 break down 1 specific AQA B2.6

Enzymes are specific 2 1 4 3 5 Enzymes have an active site . Ch3 Enzymes are specific 2 1 4 3 5 Enzymes have an active site . Substrate fits into the active site. Substrate Substrate in the active site. Enzyme releases the product. AQA B2.6

Catalase water + 1 cells 2 oxygen 3 cut 4 volume/time 5 cm3/min Enzymes Ch3 Catalase catalase hydrogen peroxide water + oxygen Hydrogen peroxide is a poison created inside 1…………. We can follow how quickly catalase reacts by timing the collection of 2……………….. Catalase is found in many types of cell. Catalase is released from the 3………. cells on the surface of a potato slice. Rate of reaction = 4……………. Rate of reaction is measured in 5………….. 2 oxygen 3 cut 4 volume/time 5 cm3/min 1 cells AQA B2.6

Amylase amylase starch sugar Enzymes Ch3 Amylase amylase starch sugar Iodine solution turns ….. - ……… with starch. Amylase enzyme digests starch into ……… Amylase is found in ………. Amylase is ………. to starch. Carbohydrases break down ………………… Proteases break down ………… ……… break down fats. blue ….... …….. ………. Amylase ……….. carbohydrates. AQA B2.6

Enzymes and temperature Ch3 Enzymes and temperature higher temperature:………………. rate enzyme starting to …………… ……………... temperature AQA B2.6

Enzymes and temperature Ch3 Enzymes and temperature Higher temperature: faster rate At a higher temperature the enzyme and substrate 1………. have more energy, so move faster and 2……… with more energy. There is an increased chance of a successful combination at the 3…….. site. Optimum This is the enzyme’s fastest 4……. …. ……... In mammals the enzyme optimum is usually about 5…… temperature. Denatured Above the optimum temperature the enzyme starts to lose its 6…….. and so the active site does not 7.. the substrate properly. Beware Some amylase made from bacteria still works at over 60° C. …....... ……… …….. rate of reaction. …… …….. … AQA B2.6

At the optimum pH the 4…… ……. is the best fit for the 5……………. Enzymes Ch3 Enzymes and pH pH too 2……..: enzyme denaturing ……: pH too low: enzyme 1…………… 6 5 …………… 4 3………… …………… rate 3 2 At the optimum pH the 4…… ……. is the best fit for the 5……………. …………. ……………. 1 4 5 6 7 8 9 10 pH AQA B2.6

Enzymes Ch3 Enzymes as builders Digestive enzymes are breakers. They break large molecules like 1…….. into small molecules like 2………… . Many cell enzymes are builders. They turn 3…… sugar molecules into 4…… molecules like starch or cellulose. Potato plant leaves make sugar by 5………….……. Potato cells need building enzymes because 6…………. starch …………... ……. ……. ……………….... they make starch in the cells for ………... AQA B2.6

Enzymes Ch3 Immobilised enzymes Industrial enzymes are immobilised by 1…….. them into small resin beads. The enzymes are kept 2………… from the product. The enzymes are 3….. likely to denature. The large substrate molecule is poured in the 4…… of the column. The small 5……… molecule runs out of the bottom. fixing separate less top product AQA B2.6

Enzymes Ch3 Enzymes in industry Breaker enzymes are used in 1…………. washing powders. These contain digestive 2………… and lipases to remove biological stains from clothes. The washing machine runs at 40°C which is the enzymes’ 3……….. Temperature. Cider makers use 4………… to help release as much juice from the apples as possible. biological …………. ………… …………. AQA B2.6

Releasing and using energy Enzymes Ch5 Releasing and using energy Cells release energy from sugars by …………………. glucose + oxygen carbon dioxide + water ……….. + 6O2 6CO2 + 6H2O Cells use this energy for: muscle contraction maintaining body temperature (in mammals and birds) building new large molecules for cell growth nerve impulses. AQA B2.6

Measuring respiration gases Enzymes Ch5 Measuring respiration gases Carbon dioxide turns ……………………. cloudy. Carbon dioxide turns bicarbonate indicator from red to yellow. More carbon dioxide is exhaled than inhaled. Rate of respiration can be measured in a respirometer. ……………… is used to remove carbon dioxide from air so that a volume change shows oxygen being used up. Respiration rate is measured as a change in volume per time. The faster energy is used, the faster the rate of respiration. AQA B2.6

Rate = 4cm/4 minutes = 1 cm/minute Enzymes Ch5 Measuring respiration gases The bubble travels…………….. cm in ………minutes. Rate = 4cm/4 minutes = 1 cm/minute More accurately: the tube has an internal diameter of 1mm the volume change = r2 x distance travelled 3.142 x 0.52 x 40 = 31.4mm3 rate = volume change/time rate = 7.85 mm3/minute. AQA B2.6

Enzymes Ch4 Digestion Digestion is the break down of large 1………… food molecules into 2…… soluble food molecules by 3……….. so that they can be absorbed into the 4…… in the 5…… intestine. Food is broken down in the mouth and by chewing to give a larger 6……… for the enzymes to act 7………. Carbohydrases break down larger carbohydrates, like starch, into 8………… . Proteases break down proteins into 9………. ……. Lipases break down fats (lipids) into 10….. ……. and 11………… . ………… ……. ………… …….. ……. ………. ………. ………….... ………………. ………….. ……………. AQA B2.6

Human digestive system Enzymes Ch4 Human digestive system 1 2 3 4 5 6 7 8 9 10 AQA B2.6

Mouth and stomach Mouth Food is broken up by 1………… . Enzymes Ch4 Mouth and stomach Mouth Food is broken up by 1………… . Saliva contains the carbohydrase 2………… Food moves down the gullet by 3…………… Stomach hydrochloric acid keeps the pH low (4…….) to kill 5………… and to provide the 6………… pH for the 7……….. enzyme to break down proteins. ………. …………... ……………. (……) …………. ……… ……… AQA B2.6