Peripheral and integral proteins differ in terms of structure, location, and function within the cell membrane. Peripheral proteins are loosely attached to the membrane's exterior or interior surface, not embedded within the lipid bilayer. They might attach indirectly to other membrane proteins or associate with the polar heads of the lipid molecules. Their roles can range from enzymatic activity to signal transduction. Integral proteins, on the other hand, span the membrane or are embedded within the lipid bilayer. Due to their position, they often function as channels or transporters, allowing specific molecules to cross the membrane. They can also play roles in cell adhesion and cell signalling.

Several factors can influence the fluidity of a cell membrane. The types of fatty acids present in phospholipids play a pivotal role. Membranes rich in unsaturated fatty acids are more fluid because the double bonds in unsaturated fats introduce kinks in their tails, preventing tight packing. Conversely, membranes with more saturated fatty acids tend to be less fluid. The length of fatty acid chains also affects fluidity: shorter chains are less viscous and hence more fluid. Additionally, external factors like alcohol can increase membrane fluidity, while specific proteins might either enhance or reduce fluidity based on their size, abundance, and interactions with lipids.

Integrins are a type of Cell Adhesion Molecule (CAM) found on the cell surface, playing a vital role in anchoring cells to the extracellular matrix (ECM). By forming strong bonds with extracellular molecules like fibronectin and collagen, integrins help provide structural cohesion and stability to tissues. These connections are not just structural; they also transmit signals between the ECM and the cell, guiding cellular behaviour and ensuring tissue health. Furthermore, by anchoring cells firmly to the ECM, integrins facilitate mechanical signal transduction, helping cells respond to changes in their mechanical environment. This dual role in structural anchoring and signalling underscores the importance of integrins in maintaining tissue strength and integrity.

If a cell lacked glycoproteins or glycolipids on its surface, several crucial processes would be impacted. First, the cell's ability to recognise and communicate with other cells would be hindered. These molecules play a vital role in cell-to-cell recognition, ensuring that cells can identify each other and form cohesive tissues. In the absence of these molecules, immune surveillance would be compromised, as immune cells would struggle to differentiate between 'self' and 'non-self' cells. This could result in an increased susceptibility to infections or autoimmune responses. Moreover, specific cell interactions, such as those leading to tissue formation or organ development, would be affected, potentially leading to developmental and physiological anomalies.

Cholesterol plays a multifaceted role in regulating membrane fluidity, acting as a temperature buffer for the cell membrane. At higher temperatures, cholesterol intercalates between phospholipids, restricting their movement and thereby reducing membrane fluidity. This ensures the membrane doesn't become too fluidic and lose its structural integrity. Conversely, at low temperatures, cholesterol prevents the phospholipids from packing closely together, averting the membrane from becoming too rigid or gel-like. Thus, by adjusting the spacing between phospholipids depending on the temperature, cholesterol ensures the membrane remains functional and maintains its selective permeability properties across different conditions.