Unit 3 Study 3

Front 1

Cellular Metabolism

Back 1

-The total number of chemical reactions that occur constantly in each living cell
-The rate of Cellular Metabolism affects the life span of an organism (high metabolism=shortened life span)

Front 2

Endergonic reaction

Back 2

Building up of simpler molecules into complex molecules with an input of energy require (A.K.A Anabolic reaction)

Front 3

Exergonic reaction

Back 3

Breakdown of complex molecules into simpler molecules with a release of energy. (A.K.A Catabolic reactions)

Front 4

ATP
adenosine triphosphate

Back 4

-Is the form of readily/immediate energy within a cell
-Energy is stored in the chemical bonds
-When a cell requires energy for its endergonic reactions the last phosphate group is removed, releasing energy.

Front 5

ADP
adenosine diphosphate

Back 5

-The remaining product after ATP is used for its energy
-Can be converted back into ATP by reattaching the last phosphate group using energy from exergonic reactions... PHOSPHORYLISATION

Front 6

Enzyme

Back 6

Are biological catalysts. This means that they speed up the rate of chemical reactions which would usually occur too slowly to sustain the life of the cell.
-Made up of proteins
-Are recyclable

Front 7

Enzymes:
Active Site

Back 7

This is a region of the protein molecule which provides a site for the attachment of reactants Enzyme and substrate combine to form an enzyme-substrate complex

Front 8

Enzymes:
Active Site 2.

Back 8

The active site combines with two or more reactants and alines them in such a way that they combine to form the required product.

Front 9

Models Of Enzyme:
The Lock and Key (old)

Back 9

The enzyme has a complementary shaped active site to the substrate fit meaning an exact fit is achieved

Front 10

Models of Enzyme:
Induced Fit (new)

Back 10

The shape of the enzyme's active site changes slightly to accommodate the substrate

Front 11

Enzyme Helpers: Cofactors and Coenzymes

Back 11

When the enzyme requires the addition of extra non-protein components to complete their active site.
-Cofactor binds to activate enzymes
-Coenzyme binds to the enzyme's active site

Front 12

Effect of Temperature :

Back 12

-At high temps. the enzyme's protein structure becomes permanently denatured and the enzyme becomes inactive even when the temp. returns to normal
-At low temps. the enzyme works slower because there are less collisions between the enzymes and substrates, but the enzyme is not denatured

Front 13

Effect of pH

Back 13

-A change of pH can result in a change in shape of the enzyme and affects its ability to combine with its substrate. Can also become denatured

Front 14

Effect of Substrate Concentration

Back 14

-Adding more substrate to the enzyme solution will increase the reaction rate until ALL active sites are occupied.
-At the SATURATION POINT, no greater speed of reaction can be reached because there is not enough enzyme

Front 15

Effect of Enzyme Concentration

Back 15

-Enzyme concentrations are regulated in response to the need of the cell
-With increasing enzyme concentration, the reaction rate increases as long as there is available substrate. If too much product is produced, it may inhibit enzyme action.

Front 16

Non-Competitive Inhibitor

Back 16

Binds to the enzymes at a site other than the active site. Changes the shape of the enzyme so that the substrate can not bind to the active site. Can be removed

Front 17

Competitive Inhibitor

Back 17

Competes with a substrate for the enzymes's active site. This bonding is permanent and reduces the reaction rate by inactivating the enzyme.