Question

Question: The proton pump shown in Figures 7.17 ad 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).

Short answer

The mechanism given in figures 7.17 and 7.18 follows the active transport process. The mechanism shown in figure 9.14 follows the passive transport mechanism.

Step-by-step solution

Transport mechanism in the body    

The body is a complex organization that involves many types of metabolic reactions.The products produced from the metabolic processes are metabolites.These metabolites are transported to different locations in the body via transport mechanisms.

Step 2: Description of active and passive transport

The pumps present in the cell membrane follows two transport pattern, namely active and passive transport. The former involves the energy requirement, and the latter does not require energy for its progress.

Comparison between Figure 7.17, 7.18 and 9.14            

Figure 7.17 shows the proton pump mechanism. The transport of positively charged ions takes place via the proton pump. It follows the active transport mechanism, which consumes energy from the hydrogen ions and the voltage gradient.

Figure 7.18 shows the cotransporter mechanism that takes place in the sucrose transport in plant cells. The proton pump pumps out the hydrogen ions. These hydrogen ions are transported along with the sucrose molecules. The concentration gradient provides energy to this reaction. So, this reaction works in the mechanism of active transport.

Figure 9.14 shows the ATP synthase, which is the enzyme employed in the synthesis of ATP. This enzyme mechanism acts along the gradient, and there is no additional energy required in this mechanism. It is known as passive transport.

Hence, the proton pump and sucrose transporter mechanism are given in 7.17, and 7.18 is the active transport. The ATP synthase shown in figure 9.4 is the passive transport.