What are the characteristics of biofilms, and the two major characteristics of biofilms

Biofilms are divided into monolayer membranes and bilayer membranes, with one membrane consisting of two layers of phospholipids.

Molecular layer composition. Biofilms include cell membranes.

Nuclear membrane and organelle membrane. Its characteristics are mainly (summarized from the Internet below)1About the properties of biofilms.

a.The more complex the function of the membrane, the greater the type and quantity of proteins.

b.The lipid molecules that make up the membrane are all amphiphilic molecules.

c.Protein molecules can rotate, flip, move sideways, etc. in the lipid bilayer of the membrane.

d.Cholesterol.

The fluidity of the membrane can be increased below the phase change temperature, and the fluidity of the membrane will be decreased above the phase change temperature.

e.The distribution of membrane lipids and membrane proteins is asymmetrical.

It is a phospholipid bilayer embedded with proteins and sugars (collectively referred to as glycoproteins), which plays a role in dividing and separating cells and organelles.

Including plasma membrane, nuclear membrane, mitochondrial membrane, endoplasmic reticulum membrane, lysosomal membrane, Golgi membrane, chloroplast membrane, peroxisome membrane, etc. The biofilms are all lamellar in morphology, with a thickness of about 5 10 nanometers. It is mainly composed of lipids and proteins, and a small amount of sugars are covalently bonded to lipids or proteins.

Different biofilms have different functions.

It has a grease valve structure.

Structural characteristics with certain fluidity Functional characteristics Selective permeability.

Biofilms have two distinct properties, namely the fluidity of the membrane and the asymmetry of the membrane.

1. Fluidity of the membrane.

The fluidity of biofilm is the continuous movement of membrane lipids and membrane proteins, which is an important condition to ensure normal membrane function. In the physiological state, the biofilm is neither crystalline nor liquid, but liquid crystal, i.e., a transitional state between the crystalline and liquid states.

In this state, it has both the fluidity of liquid molecules and the orderly arrangement of solid molecules. When the temperature drops to a certain point, the liquid crystal state changes to a crystalline state; If the temperature rises, the crystalline state can be dissolved into a liquid crystal state. The mutual transformation of this state is called phase transition, and the temperature that causes the phase transition is called the phase transition temperature.

2. Asymmetry of the membrane.

Bounded by the hydrophobic end of the lipid bilayer molecule, the biofilm can be divided into two layers, the inner and outer layers of the near-cytosolic plane and the non-cytosolic plane, and the structure and function of the inner and outer layers of the biofilm are very different, which is called the asymmetry of the biofilm.

Biofilms. The characteristics are fluidity, selectivity, permeability, and asymmetry.

Biofilms are phospholipid bilayers that mosaic proteins.

The phospholipid bilayer itself can flow, and the proteins on it can go in and out of the bilayer, or they can drift on the bilayer, and the biofilm is fluid.

The phospholipid bilayer is lipophilic but not hydrophilic, so it is easier for non-polar substances to pass through the biofilm than polar materials, and at the same time, the proteins on the membrane only allow substances of a certain conformation to pass through, so the biofilm is selectively permeable.

Asymmetry is due to differences in the composition of phospholipids on the inner and outer sides of the biofilm, and differences in the number of protein species, which leads to the asymmetry.

Fluidity contributes to the renewal of biofilms, selective permeability is helpful for absorption, hailstorming, and waste discharge, as well as certain cell-specific recognition, and asymmetry helps to maintain the difference between substances inside and outside the biofilm.

Biofilms are characterized by fluidity, selective permeability, and asymmetry.

The biofilm is a phospholipid bilayer mosaic of proteins, and the phospholipid bilayer itself can flow, and the protein on it can penetrate and exit the bilayer, or drift on the bilayer, and the biofilm reflects fluidity.

The phospholipid bilayer is lipophilic but not hydrophilic, so non-polar substances are easier to pass through the biofilm than polar substances, and the proteins on the membrane only allow substances of a certain conformation to pass through, so the biofilm is selectively permeable.

Asymmetry is due to differences in the composition of phospholipids on the inner and outer sides of the biofilm, and differences in the number of protein species, which leads to the asymmetry.

Fluidity helps in the renewal of biofilms, selection through manual simplicity helps in the absorption of substances and excretion of waste, as well as certain cell-specific identification, and asymmetry helps to maintain the difference between substances inside and outside the biofilm.

Structural characteristics of biofilms: cell membranes have a certain fluidity. The structure of the cell membrane is that the intermediate phospholipid bilayer forms the basic backbone, and protein molecules are mosaic, penetrated, and covered in the phospholipid bilayer or surface at different depths.

Functional characteristics of biofilms: separating cells from the external environment; control the movement of substances in and out of cells; exchange of information between cells; The functional property of the cell membrane is selective permeability.

The cell membrane has the function of controlling the entry and exit of substances into and out of the cell, and the entry and exit of substances into and out of the cell can be free diffusion, assisted diffusion, active transport, endocytosis and exocytosis.

The different types and quantities of carrier proteins on the cell membrane determine the different types and quantities of substances entering and exiting the cell, so the cell membrane allows water molecules to pass freely, and some ions and small molecules can also pass through, while other ions, small molecules and macromolecules cannot pass through. Therefore, the functional property of the cell membrane is selective permeability.

The relationship between the two: fluidity is the basis for selective permeability, and it is precisely because of the fluidity of membrane lipids and the motility of membrane proteins that the function of controlling the entry and exit of substances in the cell membrane is determined, thus reflecting the selective permeability.

Biofilms, also known as biofilms, refer to organized groups of bacteria that are attached to the surface of living or inanimate objects and are encased by bacterial macromolecules. Biofilm bacteria are highly resistant to antibiotics and host immune defense mechanisms.

Various major biological macromolecules such as proteins, polysaccharides, DNA, RNA, peptidoglycan, lipids, and phospholipids are present in biofilms. The formation of multicellular biofilm structures is a dynamic process, including bacterial initiation of adhesion, biofilm development, comodulation, and maturation and diffusion.