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Enzymes. identify the role of enzymes in metabolism, describe their chemical composition and use a simple model to describe their specificity on substrates. What are they?.
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Enzymes identify the role of enzymes in metabolism, describe their chemical composition and use a simple model to describe their specificity on substrates
What are they? • Enzymes are protein molecules, present in cells, which act as biological catalysts (speed up or slow down chemical reactions),controlling the rate of each step of the complex chemical reactions that take place in cells.
What is a substrate? • A substrate is the molecule on which an enzyme acts upon. E.g. Sucrose – after reaction becomes glucose and fructose.
What is metabolism? • Metabolism is the sum total of all chemical reactions occurring within a living organism. • Enzymes relate to metabolism as all metabolic reactions are catalysed () by enzymes.
Two models of enzyme reactions • Induced fit • Lock and key
Heads or Tails • There is three different models of enzymes.
The most accepted model of enzyme activity is the lock and key model.
The denaturing of an enzyme refers to when an enzyme loses its functional, three-dimensional shape and can no longer react with its substrate.
The denaturing of an enzyme can only occur from a temperature change.
A reaction occurs when a substrate interacts with an active site.
pH can change the shape of an enzyme causing it to function more efficently.
Enzymes are substrate specific. Enzymes only act on one type of substrate.