1.5: Biotechnology in Industry

Question 1

what is an enzyme?

Answer 1

An enzyme is a globular protein with specific tertiary structure that acts as a biological catalyst to increase the rate of reaction by lowering the activation energy

Question 2

what are some uses of enzymes?

Answer 2

• milk
• cheese
• marmite
• apple juice
• washing powders

Question 3

How are enzymes obtained?

Answer 3

using the whole organism in the production process
OR
through using purified enzymes produced by biotechnology

Question 4

What does using enzymes in these process mean?

Answer 4

That reactions can be carried out at lower temperatures and pressures because enzymes are biological catalysts and increase the rate of reaction by lowering the activation energy

Question 5

What can biotechnology now use microorganisms to provide?

Answer 5

A readily available source of enzymes on a large scale.

Question 6

What are most industrial enzymes?

Answer 6

Extracellular - they are secreted out of the cell

Question 7

What does extracellular cells mean?

Answer 7

That they can be easily extracted from the fermenter

Question 8

How are enzymes for industry usually produced?

Answer 8

using cheap, plentiful non toxic substrates like waste products from other industries

Question 9

What are extremophiles?

Answer 9

Certain microorganisms that can live in extreme conditions. The enzymes they produce are useful in industrial processes as they can tolerate extremes of pH, temperature

Question 10

Why are microorganisms a valuable source of enzymes?

Answer 10

• Produce more enzymes/body mass than any other organism
• Easy to manipulate genetically
• Product yield can be increased by strain selection, optimising growth conditions
• Can be grown in suitable labs anywhere
• Enzymes produced show enormous range of pH and temperature characteristics

Question 11

What did traditional enzymes technologies use?

Answer 11

The whole microorganism as a source of enzymes

Question 12

What are immobilised enzymes

Answer 12

enzymes held, separated from the reaction mixture but allows substrate molecules to bind with them. This allows the products to be removed easily

Question 13

Why are immobilised enzymes used?

Answer 13

Products produced need to be extracted from the enzyme substrate mixture, this can be costly so immobilised enzymes are used

Question 14

What are the 4 main ways of immobilising enzymes?

Answer 14

• covalent bonding
• adsorption
• Entrapment
• Membrane separation

Question 15

How are immobilised enzymes formed using covalent bonding?

Answer 15

Enzyme covalently bonded to insoluble support e.g. clay particles or cellulose fibres

using cross linking agent e.g. glutaraldehyde

Can’t immobilise large quantity of enzyme but is very efficient as no leakage because of very strong bonds.

Question 16

How are immobilised enzymes formed using adsorption or carrier bound?

Answer 16

Enzyme is mixed and bound to the immobilising support by hydrophobic and ionic links

BUT because these are weak forces the enzyme can become detached (leakage)

As long as active sites don’t distort it is very efficient

Question 17

How are immobilised enzymes formed using entrapment /microcapsule?

Answer 17

Enzymes are trapped in gel bead (e.g. alginate) or network of cellulose fibres.

Trapped in natural state so active site not affected.

Can be slow as substrate must penetrate the trapping barrier.

Question 18

How are immobilised enzymes formed using inclusion/ membrane separation

Answer 18

Enzymes physically separated from substrate by partially permeable membrane

Substrate small enough to pass through as are the product molecules

Question 19

What are the advantages of using immobilised enzymes?

Answer 19

• Easier to separate enzyme and products (cheaper downstream processing costs)
• Enzyme can be recovered and reused (useful when enzyme is expensive) so reduced cost
• Enzyme does not contaminate product/no purification required
• The matrix protects the enzyme with a physical barrier so it is more stable at extremes of pH and temperature
• Allows continuous production/enzyme used for longer/greater productivity/higher yield
• Using immobilised whole cells means several enzymes can participate in the process simultaneously

Question 20

What are the disadvantages of using immobilised enzymes?

Answer 20

• Expensive to set up as immobilization requires time/equipment
• Immobilised enzymes may be less active because they do not freely mix with substrate
• Immobilisation may alter shape of enzyme so reduce its rate of reaction
• may alter catalytic ability
• enzyme may become detached
• As it’s a continuous process any contamination is costly to deal with a whole system needs to be stopped

Question 21

What is lactose?

Answer 21

A disaccharide found in milk and dairy products

Question 22

What is lactose intolerance, and what are the symptoms?

Answer 22

lactose intoleranceis a condition in which people have the decreased ability to digestlactose

Symptoms include: abdominal pain, bloating, diarrhea, gas, nausea

Question 23

When do the lactose intolerance symptoms start?

Answer 23

These symptoms typically start 30 minutes to two hours after eating or drinking milk-based food

Question 24

What affects the severity of lactose intolerance symptoms?

Answer 24

depends on the amount a person eats or drinks

Question 25

How many adults on average have lactose intolerance?

Answer 25

The exact number of adults with lactose intolerance is unknown but one estimate puts the average at 65% of the global population

Question 26

What causes the symptoms of lactose intolerance?

Answer 26

People withlactose intolerancedon’t produce enough lactase, so lactose stays in the digestive system where it’s fermented by bacteria.

This leads to the production of various gases, which cause the symptoms associated with lactose intolerance.

Question 27

Explain how immobilising enzymes occur for lactose free milk?

Answer 27