Transcript Rate of Enzyme Activity

Aim: What factors affect the rate of enzyme
activity?
I. Factors that affect rate of Enzyme Activity
A. The amount of substrate
1. Increased amounts of substrate will speed
up reactions when there are a lot of enzymes
available for reactions.
B. Temperature
Optimum
temperature
1. In general, enzyme activity increases as
temperature increases – to a certain point.
a. Optimum temperature – the temperature
at which enzyme activity works at its highest
rate. Optimum temperature in humans is
body temperature (98.6oF or 37oC)
b. Enzyme Denaturation – when an enzyme
loses its shape and its ability to carry out its
proper chemical reactions due to high
temperatures. In humans, this occurs at
about 104oF or 40oC
C. pH – the measure of how acidic or basic
something is.
1. pH scale – 1-14. 1 is the strongest acid
and 14 is the strongest base. 7 is neutral.
2. In general, enzymes work best at a pH of 7.
Some enzymes work best at different pH levels
dependent upon where they are working. Ex:
the enzyme Pepsin in the stomach works best at
a pH of 1-3.