Question

Organisms exchange molecules with their environment to obtain the materials needed for growth and reproduction. Discuss factors that affect the rate of exchange of these molecules with the organism's environment. HELP!!

Answer 1

concentration gradients are the key to effortlessly getting what you want.  

think of it this way if you were at the top of the hill and pushed a log and then sat by and watched the log roll down the hill.  you didn't have to put much of any energy into doing this it just happened naturally.  cells and organisms do this all the time.  

another example is if I put food coloring in a gallon of water.  the gallon would gradually change colors.  this is a process called defusion and cells use this to their advantage.  our body uses this to its advantage.  when we breathe we are using defusion at its best. 

my last and final example is a fart.  think about it if you fart you can smell it right away and its probably per stinky but as time passes you can no longer smell the fart. and that is because the order has spread its self so thin that you can no longer smell it.  

so organisms can use defusion and cosmos's to their advantage and they can use different types of transport such as active transport and passive transport 

active transport is where the cell or organisms spend energy to do work.  and work could be any thing from moving to getting food and so on.  

Answer 2

Answer and Explanation:

  One of the factors that affects the rate of exchange of molecules is the surface area-to-volume ratio. When a cell has a large volume and a small surface area, it is more difficult for a cell to obtain the necessary resources from their environment because the demand for resources is high and the ability to get them is low. Thus, the rate of exchange of a cell with a large volume and a small surface area will be much lower than that of a cell with a smaller volume and a larger surface area. Another factor in the rate of molecule exchange is whether it is active or passive transport. If the necessary material is abundant in the environment, passive transport would occur, and the molecule could pass into the cell following the concentration gradient. However, if the material is more abundant outside of the cell than inside, active transport would be necessary. Active transport takes more time and energy for the cell to complete because it must move the material against the concentration gradient, from a low to high concentration. Therefore, this cause a lower rate of exchange of molecules.