Enzymes SQA Questions

What you should know - ENZYMES A c________ is a substance which helps to s______ up a chemical reaction. It remains u________ at the end of the reaction. An enzyme is a p_______ which can act as a catalyst inside l_____ c_____ (b_______ c_________). Enzymes are important for the functioning of living cells because w_______ the aid of e________ the chemical reactions would take place too s______ to maintain life. Enzymes in a cell are used in ‘b________’ or ‘s_______’ atalyst peed nchanged rotein ivingells iological atalysts ithoutnzymes lowly reakdown ynthesis

Breakdown is when an enzymes breaks down a l______ s________ molecule into s______ ones Synthesis is when an enzyme j_____ s______ substrate molecules t_________ to make a larger one P_______ and c__________ are examples of breakdown enzymes P______________ is a synthesis enzyme Enzymes are s________ – they will act only on o___ s__________ Enzymes are p________ Enzymes are affected by t__________ and __. arge ubstratemaller oinsmaller ogether epsinatalase hosphorylase pecific neubstrate roteins emperaturepH

Enzymes revision 1 ells hemicaleactions ynthesis lucose tarch egradation atalase xygen

ockey

pecific changed emperature ptimum enatured epsin 7

Effect of temperature on enzyme activity Enzyme activity increases rapidly Maximum enzyme activity- optimum temperature Enzyme is being denatured

the temperature at which the enzyme has greatest activity the pH at which the enzyme has greatest activity

pepsin catalase

8. Pepsin has a working range of ____ to _____. This means it ______________________ Pepsin has an optimum pH of ____. This means it has ________ ________ at pH 2 9. Catalase has a working range of ____ to _____. This means it ______________________ Catalase has an optimum pH of ____. This means it has ________ ________ at pH 9 pH1 pH4 is active between ph 1 and 4 pH2 maximum activity pH7 pH11 pH9 is active between ph 7 and 11 maximum activity

catalase breakdown starch synthesis Fat Fatty acids + glycerol breakdown phosphorylase

Enzymes revision 2 Speed up reactions Unchanged at the end of reaction Lower the energy needed for a reaction biological Chemical reactions Unchanged at end of reaction synthesisdegradation temperaturepH specific

Control experiment A c______ experiment is set up to prove that the r______ are due to the f______ (v_________) under i___________ ontrol esultsactor ariable nvestigation Test tube containing 2ml amylase(5% concentration) + 5ml starch solution(10% concentration) Experiment carried out in a water bath at 37ºC Aim: An investigation is set up to prove that starch is digested by amylase enzyme to maltose sugar Draw and describe the control tube

Test tube containing equal volume of water (2ml) equal volume of starch solution (5ml) equal concentration of starch solution ( 10% concentration) Same temperature ( 37ºC), same type of test tube etc The control p______ that starch digestion o___ occurs when a_______ is present roves nlymylase Q. In this investigation, what is the purpose of the control experiment

1cm 3 glucose 1 phosphate (3%) 1cm 3 phosphorylase enzyme (1%) experiment carried out at room temperature (25ºC) Aim: An investigation is set up to prove that starch is synthesised by phosphorylase enzyme from glucose 1 phosphate Draw and describe two control tubes

1cm 3 glucose 1 phosphate (3%) 1cm 3 distilled water experiment carried out at room temperature (25ºC) 1cm 3 phosphorylase enzyme (1%) 1cm 3 distilled water experiment carried out at room temperature (25ºC) AND

Reliability R_________ an experiment i_________ r________ of r_______ (__,__.__) This shows that results are not u___________ or a ‘o___ o___’ Often an a________ is then calculated epeating ncreases eliabiltyesultsRRR nrepresentative neff verage

Averages 1. Find the total number of bubbles Temperature (°C) Bubbles (number/s) Try this example … = Divide the total by the number of items There are 5 items in the table 30  5 = 6 Average = 6 bubbles/s 3.Don’t forget units in your answer To find the average number of bubbles … Temperature (°C) Bubbles (number/s)02832 Click here for answer 15 ÷ 5 = 3 bubbles/s

Percentages 1. Find the total number of bubbles Temperature (°C) Bubbles (number/s) What percentage of bubbles are produced at 30ºC? Find the total = Divide the number of bubbles at 20ºC by the total number 8  32 = 0.25 this is the decimal fraction 0.25 x 100 = 25% To find the percentage of bubbles at 20ºC … 3.Multiply the decimal fraction by 100 to get the percentage 25% of the bubbles are produced at 20ºC  16  32 = 0.5 x 100 = 50% 10ºC? 4  32 = x 100 = 12.5%

Ratios 10ºC:20ºC 4 bubbles:8 bubbles Temperature (°C) Bubbles (number/s) Write down the ratio of the numbers To find the simple whole number ratio of bubbles at 10 degrees compared to bubbles at 20 degrees … 2. Find a number that will divide into both numbers to give a whole number – in this case 2 4 bubbles  2:8 bubbles  2 =2 bubbles:4 bubbles 3. Repeat step 2 until you cannot divide again without getting a fraction 2 bubbles  2:4 bubbles  2 =1 bubble:2 bubbles

Ratios 20ºC:30ºC 8 bubbles:14 bubbles Temperature (°C) Bubbles (number/s) Write down the ratio of the numbers To find the simple whole number ratio of bubbles at 20 degrees compared to bubbles at 30 degrees … 2. Find a number that will divide into both numbers to give a whole number – in this case 2 8 bubbles  2:14 bubbles  2 =4 bubbles:7 bubbles 3. You cannot divide any more without getting a fraction so … the simple whole number ratio is: 4 :7

apple liver Equal mass of tissue Same temperature Equal concentration of hydrogen peroxide

Same apparatus with dead tissue Improves reliability 35

16 Optimum pH specific

√ specific