As ATP moves from the matrix of the mitochondrion to the cytoplasm of a cell, how many membranes will it pass?

Question

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?
· What key words does the question contain and what do they mean?

Content
· What do you know about the structure of a mitochondria? How does it relate to the question?

Consider Possibilities
· What other information is related to the question? Which information is most useful?

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

B.  2

Clarify Question
· What is the key concept addressed by the question?
        o The question asks about the structure of a mitochondria.
· What type of thinking is required?
        o You are being asked to apply your knowledge of the structure of the mitochondria to explain how many membranes an ATP molecule will cross moving from the matrix to the cytoplasm.
· What key words does the question contain and what do they mean?
        o Matrix – the inner most space of a mitochondria.
        o Cytoplasm – the fluid inside of a cell but outside of the mitochondria within the cell.
        o Mitochondria – an organelle with two membranes involved in ATP production. Gather
Content
· What do you know about the structure of a mitochondria? How does it relate to the question?
        o Mitochondria contain two membranes, an outer and an inner membrane.  The center of the mitochondria is called the matrix.

Consider Possibilities
· What other information is related to the question? Which information is most useful?
        o The ATP molecule is starting in the matrix and is moving to the cytoplasm, which is entirely outside of the mitochondria.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o Because a mitochondria has two membranes, for an ATP molecule to move from the matrix to the cytoplasm it will need to cross both the inner and outer mitochondrial membranes.  Thus the ATP molecule will cross two membranes.

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 apply your understanding of the structure of a mitochondria to explain how many membranes a molecule of ATP will need to cross to move from the matrix to the cytoplasm. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you understand the structure of a mitochondria?  Did you recall that a mitochondria has an inner and an outer membrane?  Did you remember that the matrix is inside of the mitochondria and the cytoplasm is on the outside of the mitochondria?