Carrier proteins are saturated at which point?

Question

The diagram shows the rate of diffusion into a cell using carrier proteins.







A.  1

B.  2

C.  3

D.  4



Clarify Question

· What is the key concept addressed by the question?

· What type of thinking is required?



Gather Content

· What do you know about carrier proteins? What other information is related to the question?



Choose Answer

· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?



Reflect on Process

· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

D.  4

Clarify Question
· What is the key concept addressed by the question?
        o The question asks about carrier proteins.
· What type of thinking is required?
        o You are being asked to analyze a graph on carrier proteins.

Gather Content
· What do you know about carrier proteins? What other information is related to the question?
        o Carriers must bind to the molecule they transport, so the relationship between concentration and rate of transport differs from that due to simple diffusion. As concentration increases, transport by simple diffusion shows a linear increase in rate of transport. But when a carrier protein is involved, a concentration increase means that more of the carriers are bound to the transported molecule. At high enough concentrations all carriers will be occupied, and the rate of transport will be constant. This means that the carrier exhibits saturation.
 
Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o Saturation occurs when the number of glucose molecules exceed the ability of the carrier proteins available to bind them. So at higher concentrations glucose saturates the carrier protein.

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o This question asked you to analyze a graph on carrier proteins. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that the carrier proteins were saturated at lower concentrations of glucose? Did you think that saturation occurred at middle concentrations of glucose?