Life Sciences lab classes explained

Sometimes when you are dealing with an exponential graph it is just a whole lot easier to convert the exponential graph to a straight line graph (you have done this a couple of times already in 107). For example, remember this graph - it shows how growth rate increases with increasing temperature, and the part of the graph between points a and b represents exponential increase in growth rate with increasing temperature. Now remember this equation: Where  Rt2  is the  rate of growth at temperature 2 Rt1  is the  rate at growth at temperature 1 Q10  is the  factor by which the rate increases for every 10 degrees increase in temperature t2  is  temperature 2 t1  is  temperature 1 (and remember the dot is a short hand way of writing a times sign -'x') If you want to calculate Q10, how are you going to do it? You could read a couple of points off the exponential graph and enter them into the equation above, and then re-arrange it to solve it

In your next 109 workshop (workshop 5) you will see that an exponential equation  (that describes an exponential graph)  has been converted to a straight line equation by using logarithms.  It is going to be useful for you to be able to do this conversion yourselves - and I will go through this in my next post - but before I do that I want to make sure you are ok with how to manipulate logarithms... Here are some of the laws of logarithms: 1.  Log 10  (m x n)    =     Log 10 m +  Log 10 n proof: Log 10  (100 x 100)  =   Log 10  (10000) =   4 which is the same as: Log 10  (100 x 100)  =   Log 10 100  +   Log 10 100   =   2 + 2  =   4 2.  Log 10  (m / n)    =     Log 10 m -  Log 10 n proof: Log 10  (1000 / 100)    =     Log 10 10  =  1 which is the same as: Log 10  (1000 / 100)    =     Log 10 1000 -  Log 10 100  =  3 - 2  =  1  3.  Log 10  (m n )     =    n x  Log 10 m  proof: Log 10  ( 100 2