Quick Answer: The Biomembrane Model is an enlarged three-dimensional model of a cell membrane showing the fluid mosaic structure: a phospholipid bilayer with proteins embedded in and on it, and carbohydrate chains on the outer surface. It is used in cell biology lessons on membrane structure and on how substances cross membranes.
Reading the Fluid Mosaic Model
The basic fabric of every biological membrane is the phospholipid bilayer. Each phospholipid has a hydrophilic head containing phosphate and two hydrophobic fatty acid tails, and in water the molecules arrange themselves in two layers, heads facing outward to the watery fluid on either side and tails hidden inside. A biomembrane model shows the bilayer as a slab, usually with the heads coloured differently from the tails, so the hydrophobic core that blocks most water-soluble substances is obvious.
Proteins float in and on this bilayer like tiles in a mosaic, which gives the model its name, proposed by Singer and Nicolson in 1972. Integral proteins span the membrane and include channel proteins, which form water-filled pores for particular ions, and carrier proteins, which change shape to move molecules across. Peripheral proteins sit on one surface. On the outer face, short carbohydrate chains attached to proteins and lipids form glycoproteins and glycolipids, which act in cell recognition and as receptors. In animal cells, cholesterol molecules sit between the phospholipid tails and help keep the membrane stable across temperatures. In life the membrane is fluid: the lipids and many proteins move sideways constantly.
The listing does not state which components this model labels, its size or its material, and its product image is not currently available, so confirm these details. Pairing it with an animal cell model links the membrane to the whole cell, and The Synapse shows membrane receptors and channels at work in the nervous system.
Specifications
| Model of | Section of a biological (cell) membrane, enlarged |
| Structure | Phospholipid bilayer with embedded and surface proteins |
| Components typically shown | Channel and carrier proteins, glycoproteins, glycolipids, cholesterol |
| Topics | Fluid mosaic model, diffusion, osmosis, active transport |
| Labelled components, size and material | Confirm at enquiry |
Cell Biology Lessons
- Explaining the fluid mosaic model of membrane structure
- Showing the routes for simple diffusion, facilitated diffusion and active transport
- Discussing cell recognition, receptors and the glycocalyx
- Linking membrane structure to osmosis practicals with potato strips or de-shelled eggs
Care & Handling
- Lift the biomembrane model by its base or edges; the protruding protein shapes and carbohydrate chains snap off easily.
- Clean with a soft brush and a barely damp cloth, without solvents.
- Store it flat in a closed cupboard, out of direct sunlight.
Why Choose LabEquip
Biology departments teaching cell structure at secondary and pre-university level use a membrane model because transport across the membrane is hard to picture from a flat diagram. LabEquip lists it with its biology lab products; for component labels and size, use the contact page.
Frequently Asked Questions
Why is it called the fluid mosaic model?
Fluid, because the phospholipids and many proteins move sideways within the membrane rather than being fixed. Mosaic, because the proteins are scattered through the lipid bilayer like tiles set in a pattern.
Why do phospholipids form a bilayer?
Their heads are attracted to water and their fatty acid tails are repelled by it. In water they arrange themselves with heads facing the watery fluid on both sides and tails tucked together in the middle.
What is the difference between channel and carrier proteins?
Channel proteins form pores that let specific ions or water pass through by diffusion. Carrier proteins bind a particular molecule and change shape to move it across, either by facilitated diffusion or, using ATP, by active transport.
What does cholesterol do in the membrane?
In animal cell membranes cholesterol sits among the phospholipid tails. It reduces fluidity at higher temperatures and stops the membrane becoming too rigid at lower ones, helping it stay stable.
What are glycoproteins and glycolipids for?
They are proteins and lipids with carbohydrate chains attached on the outer surface. They act as recognition markers, receptors for hormones and binding sites that help cells stick together.
Which substances can pass directly through the bilayer?
Small, non-polar molecules such as oxygen and carbon dioxide diffuse straight through the lipid layer. Ions and larger polar molecules such as glucose need channel or carrier proteins to cross.
Last Updated: September 2026
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