Biodiversity and natural resources Chapter 4.1 Plant Structure
The structure of a plant cell - I can compare the ultrastructure of plant cells with that of animal cells:
Plant cells have different organelles from animal cells
Organelle | Description | Function |
Cell Wall | Arigid structure that surrounds plant cells. It's made mainly of the carbohydrate cellulose | Supports plant cells. |
Middle lamella | The outermost layer of the cell. | This layer acts as an adhesive, sticking adjacent plant cells together. It gives the plant stability |
Plasmodesmata | Channels in the cell walls that link adjacent cells together | Allow transport of substances and communication between cells. |
Pits | Regions of the cell wall where the wall is very thin. They're arranged in pairs - the pit in one cell is lined up with the pit in the adjacent cell | Allow transport of substances between cells. |
Chloroplast | A small, flattened structure. It's surrounded by a double membrane, and also has membranes inside called thylakoid membranes. These membranes are stacked up in some parts of the chloroplast to form grana. Grana are linked together by lamellae - thin, flat pieces of thylakoid membrane. | The site where photosynthesis takes place. Some parts of photosynthesis happen in the grana, and other parts happen in the stroma (a thick fluid found in chloroplasts) |
Amyloplast | A small organelle enclosed by a membrane. They contin starch granules. | Storage of starch grains. They also convert starch back to glucose for release when the plant recquires it. |
Vacuole and Tonoplast | The vacuole is a compartment surrounded by a membrane called the tonoplast. | The vacuole contains the cell which is made up of water, enzymes, minerals and waste products. Vacuoles keep the cells turgid - stops the plant wilting. They're also involved in the breakdown and isolation of unwanted chemicals in the cell. The tonoplast controls what... |