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The essential key to the functioning of all cells.

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Presentation on theme: "The essential key to the functioning of all cells."— Presentation transcript:

1 The essential key to the functioning of all cells

2 Enzymes - Are Proteins Act as Organic Catalysts, which speed up the rate of chemical reactions Control a wide variety of reactions with cells Example: Photosynthesis and respiration are both controlled by enzyme reactions

3 There are 2 groups of enzymes: Intracellular enzymes: inside cells  speed up & control metabolic reactions; Extracellular enzymes: outside cells  include digestive enzymes which break down food

4 The Role of Enzymes - Enzymes are very specific Each enzyme only acts on one Substrate ( the compound being acted on by the enzymes) This is due to the shape of an enzyme matches a particular substrate Http://highered.mcgraw- nimation__how_enzymes_work.html

5 Enzymes Activity Enzyme Activity can be influenced by their surroundings which include – Temperature – High temperatures ( Over 40 degrees Celsius) tend to denature the enzymes permanently, at low temperatures slow down reactions, but no permanent damage is done.

6 pH Levels – Most of the time optimum activity is when there is a pH of 7, depending on the area the reaction is occurring. As in the stomach the pH is 2 and enzymes play a vital role in breaking down food. Enzymes can also be influenced by the concentration of the particular enzyme as well as the concentration of the substrate ( the substance the enzymes is acting on)

7 Enzymes are denatured beyond 40 O C Enzymes Yeast is an example of an enzyme. It is used to help a process called fermentation: Sugar Alcohol + carbon dioxide The alcohol from this process is used in making drinks and the carbon dioxide can be used to make bread rise. Enzymes work best in certain conditions: Enzyme activity TemppH 40 0 C Could be protease (found in the stomach) Could be amylase (found in the intestine)

8 Denaturation Proteins change shape when the temperature or pH reaches levels outside of the optimal range & if bonds between amino acids are broken, the protein is destroyed.

9 Uses of enzymes 1) Enzymes are used in washing powders to help digest food stains. Biological washing powders will only work on 40 0 C or lower. 2) Enzymes are used in baby foods to “pre-digest” the proteins. 3) Enzymes are used to convert starch into sugar which can then be used in food. 4) Conversion of glucose into fructose – glucose and fructose are “isomers” (they have the same chemical formula), but fructose is sweeter.

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