MAKE CONNECTIONS The proton pump shown in Figures 7.17 and 7.18 is a type of ATP synthase (see Figure 9.14). Compare the processes shown in the two figures, and say whether they are involved in active or passive transport (see Concepts 7.3 and 7.4).

Verified step by step guidance

1. Identify the main components and processes in Figures 7.17 and 7.18, focusing on the role of the proton pump and ATP synthase.
2. Understand the mechanism of the proton pump: it uses energy (often from ATP hydrolysis) to transport protons (H+) across a membrane against their concentration gradient, which is a characteristic of active transport.
3. Examine ATP synthase as depicted in Figure 9.14, which facilitates the synthesis of ATP from ADP and inorganic phosphate (Pi) using the energy from the flow of protons down their concentration gradient, a process known as chemiosmosis.
4. Compare the direction of proton movement in both processes: In the proton pump, protons are moved against the gradient (active transport), while in ATP synthase, protons move down the gradient (passive transport).
5. Conclude that the proton pump involves active transport as it requires energy to move protons against the gradient, whereas ATP synthase involves passive transport as it harnesses the energy from the movement of protons down their gradient to synthesize ATP.

Key Concepts

ATP Synthase

ATP synthase is an enzyme that catalyzes the formation of adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and inorganic phosphate. It plays a crucial role in cellular respiration and photosynthesis, utilizing a proton gradient to drive the synthesis of ATP. This process is essential for energy transfer within cells.

Active Transport

Active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration, against the concentration gradient. This process requires energy, typically in the form of ATP, to function. It is vital for maintaining cellular homeostasis and enabling nutrient uptake.

Passive Transport

Passive transport refers to the movement of substances across a cell membrane without the need for energy input, occurring along the concentration gradient. This includes processes such as diffusion and osmosis, where molecules move from areas of higher concentration to lower concentration. It is essential for the regulation of substances within cells.