2.2.3 Enzymes Worksheet



2.2.3 Enzymes Worksheet

Enzymes

Most reactions take place in a number of __________ which need to be _________________________ if the cell is to function properly

______________ are the most important controllers of cellular reactions

Catalysts

_______________ speed up reactions without themselves being involved in the reaction.

______________ are catalysts made of ____________ they speed up a reaction without being used up themselves in the reaction.

Because enzymes are made in living things they are called ____________________ (or organic catalysts)

We learned in the section on food that proteins are made when ____________________ join together.

The function of a protein is decided not only by the _______________ of amino acids but also by the way the protein __________.

Most enzymes are ________________ proteins

How enzymes work

Enzymes are not flat they have a 3D structure

Each enzyme has its own __________________________ that will only “fit” the molecule that the enzyme is designed to work on.

If the enzyme that breaks down starch into glucose meets a fat molecule it _______________________ and will not be able to work on it.

Enzyme Action

The substance that an enzyme acts on is its __________________

The substance(s) that the enzyme forms is called the ________________

A Catabolic enzyme

Amylase converts ____________ to ______________.

Catabolic as it breaks a __________ molecule into a __________ one.

It is produced by ___________________ in mouth and by the ______________.

An Anabolic Enzyme

______________________________ forms and repairs DNA.

Anabolic as it coverts __________ molecules into more __________ molecules.

Found in almost all living things

Consider This

Amylase is an enzyme found in saliva. It breaks starch molecules into smaller maltose molecules.

What is the substrate?

What is the product?

Will amylase break fats into fatty acids + glycerol?

Why?

Is this an example of a catabolic or an anabolic reaction?

Why?

And This

DNA Polymerase is an enzyme that builds DNA using tiny molecules in our cells.

What is the substrate?

What is the product?

Will amylase build keratin out of peptides?

Why?

Is this an example of a catabolic or an anabolic reaction?

Why?

Enzymes work because they have the correct shape to fit the substrate.

They have a ______________________________________________ shape to fit the substrate.

When enzymes and their substrates meet and come together they form an _________________________________ complex.

Enzyme Reactions are ___________________.

Like a key can open or close a lock enzymes can ________________________ ________________________________.

In the following example the enzyme can break molecule X into Y+Z but it can also combine Y+Z to form X

Naming Enzymes

Enzymes are named by adding the suffix ______ to the name of their _________________.

Eg.

Enzyme that acts on Amylose (starch) is called ______________.

Enzymes that act on proteins are called __________________.

Inhibitors

Inhibitors attach to enzymes and _______________________________.

When this happens the enzymes are said to be __________________.

Nerve Gases

The nerve gases we hear of terrorists using are often ________________ that attach to enzymes involved in our ___________________________.

Poisoning people the old fashioned way!

______________ denatures an enzyme involved in _____________________.

Beneficial Inhibitors

________________________ affect ______________ in insects causing their death.

__________ can affect ______________ involved in pain causing the pain to stop.

____________________ can affect ______________ in bacteria causing the bacteria to die.

Enzymes at work!

Enzymes work best in certain conditions

Factors that affect enzymes include:

______________

______________

______________ concentration

______________ concentration

We will be examining these in experiments

Temperature

At very low temperatures ice forms, liquids become solids and enzymes can’t work.

As temperature increases molecules start to ___________ and bump into each other causing the rate of reaction to _______________.

Human enzymes work best at ___________________ (____°C)

Plant Enzymes work best at ____-____ °C

Above certain temperatures enzymes start to lose their __________ the rate of reaction __________.

When the shape is fully lost the enzyme is said to be __________________ this is usually a ___________________ condition.

pH

pH scale goes from 0 -14

0-7 is ___________

7-14 is __________ (or ________________)

Enzymes work over a ________________ pH range

Most enzymes work at pH ____ - ____

Outside this they lose shape and get __________________

The ________________ or best pH is usually pH 7

An Exception!

Is our stomach acid or basic? __________________

Do you think there are enzymes in our stomach? ________________

____________ is an enzyme in the stomach that works best at pH 2!

Immobilised Enzymes

__________________________ is the use of enzyme controlled reactions to produce a product.

Bioprocessing can be used to produce a vast range of products such as ______________, beer, _____________________, vaccines, methane gas, food flavours, vitamins and perfumes.

Traditionally microorganisms such as _____________ and __________ were used but since the 1900’s and especially since the 1950’s ______________ are being used.

If enzymes are used freely _________________ in a vessel it can be very wasteful as they are ________ at the end of the process

To prevent this problem enzymes are often _____________________ or fixed.

This means they are ________________ to ______________ or an _________ _______________ and can be used repeatedly.

How to immobilise enzymes

Physical methods

__________________ where enzymes are physically attached to inactive supports such as glass beads or ceramics.

_______________________________________________ when enzymes are kept within a membrane.

____________________, sodium alginate is commonly used this allows substrates in and products out.

Chemical Methods

_______________________ enzymes chemically bonded to a support such as glass beads or ceramics.

________________________________. Enzymes are chemically bonded to each other.

Advantages of Immobilised Enzymes

_________________ of enzyme is not affected

Immobilised enzymes can be __________________________ from the product so you can get a pure sample of product easily.

Immobilised enzymes ______________________ this cuts costs.

Enzymes ________________ become _________________________ when immobilised.

Uses of Immobilised Enzymes

Immobilised glucose isomerase converts ______________ to ______________ which is used to sweeten drinks.

Penicillin acylase changes the _______________ of penicillin to make more _________________ that will fight a wider range of bacteria

Lactase converts _____________ to sweeter sugars ______________ and ___________________ which are then used by food manufacturers

Syllabus Can you.......

• Define the term: enzymes

• State the nature, folded shape & functions of enzymes.

• Explain the role of enzymes in plants and animals including role in metabolism

• Explain the effects of pH & temperature on enzyme activity.

• State the procedure and advantages of Bio-processing.

• State the use of Bio-processing.

END

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