Plant cells are fascinating because unlike animal cells they must hold a more rigid structure. Plant cells have features which animal cells lack that give them special properties such as the ability to do photosynthesis. Here we're going to go through how to draw a plant cell with all the components you need for it to be fully functional.
Know your audience
There's no point in spending hours meticulously shading in all your thylakoid stacks if the audience your illustration is aimed at doesn't even know what a cell is, let alone a chloroplast. As much fun as it might be to try and explain the Endosymbiotic theory to them (and subtly suggest that all plants are out to eat them), you might want to save yourself the hassle (and several pencils).
Key Stage 2, ages 7-11
Children probably won’t have been taught about cells at this stage. They will have learned the word cell in physics though. Don't confuse them.
"...Wait, what? I thought a cell was a battery. Does that make a potato clock a plant cell?"
Key Stage 3, ages 11-13
At this age group, students need to be aware of the cell membrane, cell wall, the vacuole, the cytoplasm and the nucleus. They'll probably also have covered chloroplasts, although might not know what they look like beyond little green dots inside the cell. .
Key Stage 4, ages 14-16
At this age group, students need to be aware of the cell membrane, the cytoplasm, the nucleus, mitochondria and ribosomes.
Key Stage 5, ages 16-18
Students need to know about cytoplasm, cell membranes, the nucleus, mitochondria, ribosomes, rough and smooth endoplasmic reticulum, golgi apparatus, lysosomes and centrioles. They also need to know about the cell wall, chloroplasts and the vacuole. They should also be aware of the lipid bilayer structure of membranes.
Know Your Structures
Plant cells vary only slightly in composition from animal cells, they share many of the same organelles (components of cells with functions that aid the cell in surviving).
A cell wall
2 micrometers thick, rigid and surrounds the whole cell.
Wall it in
One thing all plant cells have that separate them from animal cells is a wall surrounding them. Under the microscope they usually appear hexagonal in shape. The cell wall is only slightly thicker than the membrane around the cell. Cell walls are composed of cellulose, hemicellulose, pectin and soluble protein. This gives them the ability to withstand mechanical and osmotic pressure, meaning they don't burst like animal cells do. Pressure that is exhibited on the wall from the inside is called turgor pressure and is very important structurally to the cell and the plant itself. The reason your plants start to droop when you don't water them is because there isn't enough water to exert turgor pressure on the cell wall. They become like slightly deflated bouncy castles and don't stand up straight any more.
Essentially the cell’s most outer barrier that controls what is allowed into and out of the cell. It’s about 7 nanometers thick, made of 2 layers of molecules called phospholipids, long chains of fatty acid molecules with ‘Hydrophilic’ heads.
Composed of an inner ball of DNA ( called the nucleolus), surrounded by a ‘nuclear envelope’ a spherical shape about 7 micrometers big in diameter that’s covered in tiny holes called pores.
A space inside the cell about 3 micrometers in diameter that usually contains fluid that gives the cell turgidity, allowing it to hold its shape and withstand physical pressures.
Vacuoles - vacu doesn't mean vacuum
A common misconception about vacuoles is they're empty. They're not, although the ‘vacu-‘ part of the word doesn't really help the cause,. Instead within the vacuole there are often fluids such as water, as well as dissolved compounds like pigments. Try and represent this in your drawings for greater detail. Some compounds that can be found inside include digitalis from foxglove flowers and alkaloids like opium that gives them a distinctive purple colour. They can also contain reserves of waste products, temporarily or permanently, and/or a reserve of toxins, to serve as a defence from predators.
These are very interestingly shaped organelles, oval shaped capsules with 2 layers to its membrane, the inner layer folds up on itself (like it’s been squished inside). 1 x 3 micrometers big. Mitochondria are where respiration takes place and most of the components involved are based within the inner membrane.
Chloroplasts are similar sized to mitochondria. They have a double membrane on the outside and are filled with membrane sacs called thylakoids. Thylakoids are where photosynthesis takes place and stack up to make grana.
0.1-1.2 micrometers big, these vesicles contain lysozyme enzyme at an acidic pH of 4.5 to 5 for destroying faulty proteins and pathogenic material.
Smooth Endoplasmic Reticulum
Smooth endoplasmic reticulum is a region of infolded membranes that is responsible for the production of fats and steroid hormones. It tends to start near the nucleus and extend outwards. Most of it is joined together so it looks a bit like ant tunnels.
Rough endoplasmic reticulum
Rough endoplasmic reticulum is so-called because it looks exactly like the smooth endoplasmic reticulum, but studded with ribosomes. Each layer is about 0.2 micrometers thick and the organelle is responsible for packaging and dispensing proteins to the outer membrane.
Made up of 7 nanometers thick layers folded on top of one another called cisternae, this organelle is required for transporting proteins and compounds into the cell and assisting them in reaching their target location. It is located next to the endoplasmic reticulum and plant cells can contain hundreds per cell.
They are cellular ‘workbenches’ that translate RNA into strings of Amino Acids that fold up to make proteins. They are 30 nanometer big spheres that exist all throughout the cell, especially in the nucleus and along the outside of the rough endoplasmic reticulum.
Tiny spheres about 30 nanometers in diameter that contain lots of enzymes that cells need to function.
Make it as simple as possible, but no simpler
Drawing a plant cell is about showing that you understand that there are many different components to a plant cell, but you don't have time to go all Michaelangelo on them. No-one needs the Sistine chapel in their exercise book. Equally if you draw them all as amorphous membrane sacs, people may wonder whether you were accidentally handed an adipocyte that class. Get the relative sizes correct and add any little details to the chloroplasts and mitochondria to make it clear you know what you're on about.
Did we miss any organelles out that we shouldn't have? Put them in the comments below!