Question: what is it so special about plant cells?

Scottish Wildcat answered on 20 Nov 2017:

One reason that plant cells are special is because they have a cellulose cell wall surrounding them. This allows plants to grow upwards and hold their leaves where they can absorb sunlight. The mechanical strength of the walls is what gives large plants like trees a supporting structure of wood, but an important aspect of cell walls is that they allow pressure to build up inside cells and create a supporting structure for the herbaceous (non-woody) parts of plants in which the cell walls are stretched.

The pressure builds up inside a plant cell when ions are pumped into the cell by specialised transporter proteins in the cell membrane, which is not otherwise permeable to the ions. Plants are also special because many types of plant cell have a vacuole inside them with its own membrane and transporter proteins.

One of the functions of the vacuole is a place for plants to store toxic ions and other chemical compounds that they absorb from the soil, in a place where they don’t interfere with the normal chemical reactions occurring inside the cell. The outer, epidermal cells, of many plants accumulate compounds that absorb UV light in their vacuoles to provide a sun-screen for the underlying cells, which are very special because they have small green organelles called chloroplasts inside them that are capable of photosynthesis.

Light and carbon dioxide are captured by the chloroplasts and stored in the form of starch. The starch can later be broken down into glucose and used to build new cell walls, or further metabolised by the cell to provide energy needed for multiplication and repair of plant cells during growth. Plants are autotrophs and feed themselves. Most other higher organisms are heterotrphs and depend, directly or indirectly, on plants to obtain the energy they need to survive. In the dark, plants use their starch.