Endocytosis and Enocyyosis are forms of active transform. What is active transform?
The movement of molecules up a concentration gradient from low to high, using energy
The movement of molecules down a concentration gradient from high to low, using energy
The movement of molecules up a concentration gradient from low to high, using no energy
The movement of molecules down a concentration gradient high to low, using no energy
The correct answer is: The movement of molecules up a concentration gradient from low to high, using energy.
Active transport is the movement of molecules against their concentration gradient, from an area of lower concentration to an area of higher concentration. It requires the expenditure of energy in the form of ATP (adenosine triphosphate) to transport molecules across the cell membrane. Therefore, the correct answer is:
The movement of molecules up a concentration gradient from low to high, using energy
To determine the correct answer, we first need to understand what active transport is. Active transport refers to the movement of molecules across a cell membrane against their concentration gradient, from an area of lower concentration to an area of higher concentration. This process requires the expenditure of energy by the cell and is typically facilitated by protein pumps.
Now, let's analyze the given options:
Option 1: The movement of molecules up a concentration gradient from low to high, using energy - This option correctly describes active transport. Molecules are transported against their concentration gradient, from an area of lower concentration to an area of higher concentration, which requires the cell to expend energy.
Option 2: The movement of molecules down a concentration gradient from high to low, using energy - This option describes passive transport, not active transport. In passive transport, molecules move down their concentration gradient, from an area of higher concentration to an area of lower concentration, without requiring energy expenditure.
Option 3: The movement of molecules up a concentration gradient from low to high, using no energy - This option does not describe active transport accurately, as active transport necessitates the use of energy by the cell.
Option 4: The movement of molecules down a concentration gradient from high to low, using no energy - This option correctly describes passive transport. Molecules move down their concentration gradient, from an area of higher concentration to an area of lower concentration, without the need for energy from the cell.
Based on the explanations above, the correct answer is: The movement of molecules up a concentration gradient from low to high, using energy.