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In this topic of IBDP Biology, we will learn about Plant Cell Structure.
Plant Cell Structure
- When it comes to IBDP Biology, plant cells are eukaryotic.
- As are animals, fungi and protoctists.
- They contain a nucleus and other membrane bound organelles:
- Mitochondria, ER, generally one Golgi.
- However, there are fundamental differences between plant cells and animal cells.

Structure in plant cells not animal cells
- Cell wall
- Thick layer outside the cell membrane to give strength and rigidity.
- Major component is cellulose.
- When it comes to IBDP Biology, cell wall allows movement of water through and along it.
- Have channels called plasmodesmata which connect the cytoplasms of adjacent cells.
- Primary cell wall – made of cellulose;
- Secondary cell wall – produced in some plant cells when fully developed, eg xylem.
- Contains cellulose and can contain lignin which makes it impermeable
- Chloroplast
- Site of photosynthesis, only found in plants and algae.
- 5 to 10 micrometers long.
- Double membrane – chloroplast envelope.
- Thylakoids
- Membranous discs
- Photosynthetic pigments are embedded in the membrane.
- Stacked into grana
- These are linked by intergranal lamellae.
- Fluid filled matrix is called stroma.
- This also contains starch grains, ribosomes, and circular DNA.

- Vacuoles
- Membrane–bound sacs = tonoplast
- Contain cell sap:
- Sugars, amino acids, pigments, mineral salts.
- Aqueous solution
- Stores food.
- Help keep cell rigid and turgid.
Specialised plant cells
- When it comes to IBDP Biology, plant cells have numerous adaptations, eg:
- Photosynthesis - palisade cells.
- Long thin and cylindrical, tightly packed:
- Forms a continuous layer that absorbs sunlight.
- Numerous chloroplasts:
- Capable of moving towards the side where light is entering.
- Large vacuole:
- Mantains turgor.
- Pushes chloroplasts towards edges of cell.
- Long thin and cylindrical, tightly packed:
- Photosynthesis - palisade cells.

- Transport
- Xylem:
- Dead cells forming vessels.
- Allows for transport of water and dissolved nutrients up the plant.
- Extra thickening with lignin.
- No cytoplasm.
- Xylem:

- Water uptake – root hair cells:
- Form the piliferous laer around the root.
- Long cytoplasmic processes called root hairs.
- Increase the surface area for water transport.

This is the end of this topic
