According to the well-known theory of transport of solutes across a cell membrane,what happens when sugar is passed through it?

When does the rate of active transport reach its maximum?

Read the following statements regarding porins and select the correct option given below:
$I$. Porins are transport proteins.
$II$. Channel proteins are a type of transport protein,which are usually gated.
$III$. Carrier protein binds the particular solute to be transported.
$IV$. Particular solute is delivered to the other side of the membrane by carrier proteins.

The transport rate reaches a maximum when:

Active transport is affected by

Choose the correct sentences for diffusion:
$(1)$ In diffusion,molecules move in a random fashion.
$(2)$ Diffusion rates are affected by the gradient of concentration.
$(3)$ Diffusion is a slow process and is dependent on a 'living system'.
$(4)$ Movement by diffusion is passive.