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ENZYME
Enzymes
Are protein molecules made by living cells
Enzymes
Act as catalysts : speed up the rate of metabolic reaction
Enzymes
Not chemically changed at the end of reaction
General characteristics of enzymes
General Characteristics Of EnzymesGeneral Characteristics Of Enzymes
speed up the rates of biochemical reaction in the cells
speed up the rates of biochemical reaction in the cells
General Characteristics Of EnzymesGeneral Characteristics Of Enzymes
Only a small amount of enzyme is needed to catalyzed a lot of substrate
Only a small amount of enzyme is needed to catalyzed a lot of substrate
General Characteristics Of EnzymesGeneral Characteristics Of Enzymes
very specific – each class of enzyme will catalyze only one particular reaction
very specific – each class of enzyme will catalyze only one particular reaction
General Characteristics Of EnzymesGeneral Characteristics Of Enzymes
Not used up or destroyed in the reactions that they catalyse, but can be reused again
Not used up or destroyed in the reactions that they catalyse, but can be reused again
General Characteristics Of EnzymesGeneral Characteristics Of Enzymes
Catalyse reversible reactionCatalyse reversible reaction
General Characteristics Of EnzymesGeneral Characteristics Of Enzymes
Many enzymes are only able to work in the presence of a coenzyme (or cofactor)
Many enzymes are only able to work in the presence of a coenzyme (or cofactor)
General Characteristics Of EnzymesGeneral Characteristics Of Enzymes
Enzymes are affected by changes in temperature & pH
Enzymes are affected by changes in temperature & pH
Naming of enzymes
An enzyme is named by taking its substrate and adding the suffix ‘-ase’
Sucrose + water glucose + fructose
Types of Enzyme
TYPE OF ENZYMESTYPE OF ENZYMES
• Catalyses reactions within a cell• Formed on free ribosomes in the
cytoplasm
Intracellular EnzymeIntracellular Enzyme Extracellular Enzyme
• Leaves cell and catalyses reactions outside
• Synthesized on ribosomes attached to rough ER
Synthesized of extracellular enzyme
Mechanism of enzyme reaction
Enzyme substrate complex
Effect of pH on enzyme
Effect of temperature
The Uses of Enzyme
Application Enzymes used Uses
1 Dairy industry Rennin Coagulate milk proteins in cheese manufacturing
Lipase Used in the ripening of cheese
2 Fish industry Protease Removes the skin of the fish
3 Baking industry Amylase Breaks down of starch to glucose
Protease from microorganisms
Breaks down and lower proteins in flour for biscuit manufacture
4 Brewing industry
Amylase from germinating barley
Breaks down of starch to glucose for fermentation by yeast
Protease Breaks down of protein to amino acid for yeast
Removes cloudiness during the storage of beers
Application Enzymes used Uses
5 Biological detergents
Protease, lipase and amylase
Removes organic stains (blood, food, saliva) from clothes
Amylase Removes resistant starch residues
6 Leather tanning industry
Protease Removes hair from animal hides and make leather softer
7 Textile industry Amylase Removes starch that is applied to threads to prevent damage during wearing
8 Processing food Trypsin To pre-digest some baby foods
Amylase Converts starch to glucose syrup
9 Paper industry Amylase Partial breakdown of starch to fill the gaps between fibres to produce smoother paper
10 Medical analysis Trypsin Removes blood clots and cleans wounds