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Flashcards in Enzymes Deck (16):

What do enzymes do?

They act as catalysts to speed up the rate of reactions by lowering the reactions required activation energy


What are anabolic reactions?

a + b -> c
I.e. Energy is absorbed and things are built up


What are catabolic reactions?

a -> b + c
I.e. Energy is released and substances are broken down


Will having enzymes in a reaction result in a higher or lower yield of products then a reaction without them?

The yield will remain the same as enzymes only change the rate at which a reaction occurs


How do enzymes act on substances?

They draw specific substrates into their complementary active sites and lower the activation energy required for a reaction to proceed


What are the main structural components of enzymes?

They have an active site which is where substrates bind to

They are proteins that consist of one or more polypeptide chain (generally made up of many)

They are soluble globular proteins


How does temperature affect enzyme activity?

Speeds up rate of reaction as temp increases but if the temp continues to increase it will reach a point where the enzyme is denatured causing the enzyme to loose its shape and be unable to function


How does pH affect enzyme activity?

Increasing pH = increase in rate of reaction, unless pH is so high it denatures the enzymes


How does increasing enzyme concentration effect the rate of a reaction?

Increasing enzyme concentration = increased rate of reaction.

It may reach a saturation point is there is a limited amount of substrate


How does increasing substrate concentration affect the rate of a reaction?

Increased substrate concentration = increased rate of a reaction

It will reach a saturation point as more substrate is added as it will reach a point where all the enzymes are active and catalysing the reaction


What are enzyme inhibitors?

Molecules that bind to an enzyme and prevent the enzymes specific substrate from binding to it, I.e. It inhibits the reaction


What are competitive inhibitors?

Inhibitors with a similar shape to the enzymes substrate, which will bind to the enzymes active site and block substrates from binding to it


Are are non competitive inhibitors?

Inhibitors that bind to an enzymes allosteric site and cause the enzyme to change shape, hence the substrate will no longer fit or be able to bind with the active site


What are co enzymes?

An organic cofactors that sits in an enzymes active site and helps the substrate fit in better to the active site


Why are new coenzymes needed for each reaction?

Because they are broken down each time and aren't useful to the reaction in that state


How long do enzymes work for?

Enzymes can continue to catalyse reactions over and over again as they aren't used up in it. They work until external factors result in damage to the enzyme