What are the optimum operating conditions for enzymes?

type of enzymes

Conditions - what could affect enzyme activity?

chosen

concentration of

Oxidoreductases

dependent enzyme to test on

independent condition for the test

methods

equipments / materials

testing technique

substrate

enzyme

pH

temperature

amount of energy

surface area of enzymes and substrate

inhibitors

proteins can be denatured at certain temperatures leading to change of shape of enzymes, can no longer bind with substrate. All reactions are faster at a higher temperature. However, enzyme-catalyzed reactions become slower or stop if the temperature becomes too high. The optimum temperature is usually around body temperature (37°C).

higher concentration of substrate increases the rate of reaction as the available enzymes would be working at their maximum rate

speeds up reactions until substrate amount Is limited

competitive

noncompetitive

higher or lower in acid or alkaline can interfere enzyme structure

more heat = more kinetic energy (however see 'temperature')

competes for active site so the substrate could not bind with the enzyme

alters the structure of enzyme as it binds to the other parts of the enzyme so the active site is no longer functional

Transferases

Hydrolases

Lyases

Isomerases

Ligases

transfers chemical group from one molecule to another

catalyze the joining of two large molecules by forming a new chemical bond

catalyze the breakdown of chemical bonds through methods other than hydrolysis or oxidation

catalyze bond cleavages by reaction with water resulting in the division of a larger molecule into smaller molecules

catalyze electron transfer from one molecule to another

catalyze reactions involving a structural rearrangement of a molecule

present in the metabolism and genome of most living organisms

salinity

changes salt concentration, adds or removes cations & anions, disrupts bonds, disrupts 3D shape, denatures protein

where can enzymes be found

digestive system

mouth - salivary glands

amylase

stomach

protease

pancrease

lipase, protease, pancreatic amylase

enzyme rich foods e.g. pineapples papayas

enzyme supplements

enzyme laundry detergent

Type of reactions

gas production

digestion of a solid

digestion of a liquid

colour change

testing for catalase enzyme by detecting the oxygen gas produced

using paper discs soaked in 0.05% catalase solution put into different temperatures of 0.5% hydrogen peroxide. The reaction rate is then timed from the time the disc reaches the bottom to when the discs float to the surface.

Catalase is a common enzyme found in most living organisms. Catalyzes the decomposition of hydrogen peroxide to water and oxygen.

temperature of 0.5% hydrogen peroxide, since temperature Is one of the factors that affect the rate of reaction, and the chosen dependent enzyme, catalase, acts on hydrogen peroxide.

water bath should be used to hold the samples at a constant temperature

37ºC Is our body's temperature therefore the different temperatures range from here. Collecting data from 5 samples, the temperature of 0.5% hydrogen peroxide would be 10ºC, 30ºC, 50ºC, 70ºC, and 90ºC. Water should not boil for safety reasons.

catalase solution 5mL concentration 0.05% for paper discs to soak

0.5% hydrogen peroxide at temperature 10ºC, 30ºC, 50ºC, 70ºC, and 90ºC as 5 samples (independent variable)

hole puncher for making paper discs

tweezers to transfer paper discs from catalase solution to hydrogen peroxide

measuring cylinder to measure 10mL of hydrogen peroxide Into each tube

6 tubes, one for controlled, other 5 for the samples

stopwatch to time

sharpie to mark each sample correspondingly

beaker to hold catalase solution

aim: to Investigate the optimum operating conditions for enzymes

by testing the rate of reaction of catalase at different temperatures of hydrogen peroxide

goggles, gloves, aprons, and hair-tie for long hair

uncontrolled

the environment - temperature fluctuations can affect the experiment as temperature Is one of the factors that affect the rate of reaction, therefore a water bath should be used to control the temperature of the samples

Contamination - contamination can occur and affect the experiment,

can be observed

can be observed

can be observed

can be observed