Background infomation
Role of enzymes in metabolism
Can either combined substrates or break them apart
Role of enzymes in metabolism
speeds up chemical reactions
Catabolic reactions
Simple model to describe how they fit to specific substrates
Anabolic reactions
without enzymes reactions that occur in cells.
metabolism is all chemical reactions that occur in an organism
specific enzymes catalysis specific reactions
breaks down the substrate
combines substrates together
a substrate fitting into a specific active site once the enzyme has connected
Chemical composition of enzymes
Enzymes are proteins
Not used up in the reaction
Have a particular shape
shape of active site will only fit to specific substrates
he surface of enzyme is called active site
substrates bind with active site
Effects of the environment on enzyme activity
Change in pH
Difference alkalinity and acidity levels can affect the shape of the active site.
Enzymes function best at body temperature of an organism in which they are found
As temperature increases the rate of reaction increases until the optimum is reached
Increase in the temperature
After optimum temperature is reached enzyme will start to denature and the rate of reaction will slow
importance and need for the maintenance of a constant internal environment
has enzymes denature when the internal environment changes
active site changes
Chemical reactions don’t speed up / occur has enzymes don’t work
the cell cannot function properly without enzymes working.
Change in substrates concertation
Higher the substrate concertation, greater the rate of reaction.
substrate cannot bind to enzyme
Once substrate has reached at the saturation point.
Specific optimum ranges for temp, pH and substrate conc.
pepsin and proteins in egg whites
Optimum pH
Optimum Temp.
1.5 - 1.6 pH
37-42 degrees
Caltase in yeast and hydrogen peroxide
Optimum Temp.
Optimum pH
1.5 - 2 pH
37 degrees
glucose in yeast and glucose
Optimum temp.
optimum pH
20-30 degrees
4-4.5 pH
the rate of reaction will slow down
the substrate will not increase the rate of reaction
important to maintenance a constant internal environment
will be slow and the cell wouldn’t function at optimum range
substrate complex is formed chemical reactions will take place
