Key concepts : enzymes/bio molecules * Flashcards
What are enzymes?
proteins that function as biological catalysts
(speed up reaction without being used up or chemically changed)
What is the active site of an enzyme?
The place where smaller molecules (substrates) can fit into them
What is the lock and key hypothesis?
the shape of the active site matches the shape of its substrate molecules
makes enzymes highly specific
Describe how an enzyme joins with and changes a substrate
- the substrate collides with the active site and becomes attached, forming enzyme-substrate complex
- enzyme catalyses the alteration of the substrate
- the products are released from the active site
What is denaturing?
when enzymes are exposed to extremes of pH or high temperatures the shape of their active site changes
means the substrate can’t fit into the enzyme so the reaction can’t be sped up
How do you calculate the rate of reaction?
rate of reaction = amount of substrate used or product formed / time taken
What happens to the rate of reaction as the temperature increases?
rate of reaction increases
if temperature becomes too high, the enzyme will be denatured
What is the optimum temperature?
the temperature where the rate of reaction is quickest, before it becomes denatured
different enzymes have different optimum pHs
What happens to the rate of reaction when the pH is increased?
the rate of reaction increases until it reaches the optimum pH
then the enzyme becomes denatured
What will happen to the rate of reaction if there is a higher substrate concentration?
Explain why
the rate of reaction will increase until the enzymes become saturated and no more substrates can fit at any one time
the more substrates there are, the more likely a successful collision
all the enzymes are joined with a substrate so the rate of reaction stops increasing
Name four carbohydrates
glycogen, starch, sucrose and glucose
What are carbohydrates broken down into?
simple sugars
Which enzyme breaks down carbohydrates?
carbohydrase enzymes
Where are carbohydrase enzymes produced in the body?
mouth (saliva), pancreas and small intestine
What is are proteins made from?
amino acids
