State two functions of proteins in cell membranes.

Functions of membrane proteins can be remembered using the mnemonic called JETRAT

• Junctions – Serve to connect and join two cells together 
• Enzymes – Fixing to membranes localises metabolic pathways 
• Transport – Responsible for facilitated diffusion and active transport 
• Recognition – May function as markers for cellular identification 
• Anchorage – Attachment points for cytoskeleton and extracellular matrix 
• Transduction – Function as receptors for peptide hormones

Two functions of proteins include maintaining stability and shape as well as assisting in cell to cell communication.

Hi Kiana,

Firstly one of the most major uses of proteins within cell membranes would be how they help facilitate active or passive movement of molecules through the membrane. The proteins I'm referring to would be channel and carrier proteins.

Another use of proteins in cell membranes would be maintaining rigidity and membrane structure, this is attributed to cholesterol ( a lipoprotein ). Cholesterol causes the phospholipids to be packed more tightly around it, thus leading to greater membrane strength.

Hope this managed to help you out,

Kian.

Proteins play very very important roles in every cell. This is especially true within the cell membrane where they are essential to the functioning of a cells. One function is as protein channels or carrier that allows certain molecules to move enter or leave the cell that otherwise would not be able to. Proteins also function in cell recognition where lipids and carbohydrates can join to them to form cell receptors that help with cell to cell communication.

There are different types of proteins which function in the cell membrane. Two examples include...

• CARRIER PROTEINS= these bond to a solute and experience a conformational change to transport the solute across the membrane. They are able to conduct active transport through the binding of ATP.
• CHANNEL PROTEINS= are proteins which have a pore an allow the transport of ions through the membrane. These proteins are unable to conduct active transport, but have a faster rate of reaction compared to carrier proteins.

Channel proteins embedded throughout the cell membrane act as pores in the membrane to allow water molecules or small ions to pass through quickly. This method of transport is via facilitated diffusion.

Carrier proteins bind to specific solutes and aid in the transfer across the lipid bilayer by undergoing changes to their structure to allow the molecules to pass through more easily.

Membrane proteins have a wide range of functions that are crucial to our body. This includes maintaining the shape of the cell and to transport material in and out of the cell.

Proteins are the most important functional part of cell membrane which enables cells to interact with the outer environment by providing a channel.

1. Proteins form different transport channels to allow permeability to some extent for selective ions like sodium and potassium as in ATPase pump.

2. Proteins also perform various site specific enzymatic reactions that are required at the cell membrane like flippase activity to ensure even distribution of lipids in the membrane layer.

For transport of molecules across membrane

As receptor site fro recognition of other molecules

Hello, proteins have several functions in cell membranes. This includes cell surface receptor molecules which become activated and lead to the activation of downstream pathways within the cell. Other functions include supporting the rigidity of the dynamic membrane such as cholesterol. There are also membrane pores made up of proteins enabling the transport of material between the inside and outside of the cell.

Cell membrane proteins play a very important roles in the whole functioning of the cell. Two main roles are:

1. They transport substances into and out of the cell.

2. They act in cell-cell recognition patterns by providing unique cell receptors on cell membrane.

Diffusion of molecules and active transport of molecules. Both enable molecules to enter or leave the cell. Diffusion is a passive process whereby the protein enable an open channel for the molecules to pass through the cell surface membrane. These molecules are hydrophilic and/or large and requires a hydrophilic channel to help it pass though the membrane. The proteins which enable active transport use energy in the form of ATP to push molecules across the membrane against a concentration gradient.

Membrane proteins carry out functions as diverse as carrying nutrients across the plasma membrane, receiving chemical signals from outside the cell, translating chemical signals into intracellular action, and sometimes anchoring the cell.

1. To facilitate passive or active transportation of molecules into, or out of the cell.
2. Metabotropic receptors that facilitate biochemical cascades or other events in the cell.

as a receptor, as a carrier