Question

Give a one sentence description description of the role of membrane proteins in the following

• Transport -active transport, facilitated diffusion - requires concentration gradient

• Enzymatic activity -  
• Signal transduction –

• Cell-cell recognition -
• Intercellular joining -
• Attachment -

Answer 1

Solution:-

Membrane protein are the part of biological membrane. Integral membrane protein are the permanent part of membrane and are able to penetrate the membrane. Peripheral membrane protein are transiently associated with the cell membrane. There are several functions that membrane protein are involved in like transport, enzymatic activities, cell to cell recognition, attachment, signal transduction, intercellular joining and diffusion.

Answer:-

Transport - hydrophillic channel - protein helps in transportation of various molecules across the membrane through channel by active or passive transport.

Diffusion - faciliated diffusion - diffusion of solutes through transport protein in the membrane moving down the concentration gradient.

Enzymatic activity- sequential steps in metabolic pathway - built a exposed active site for reactions.

Signal transduction - relay chemical messages - a mechanism that helps in transmission of molecular signals from exterior to interior of the cell.

Cell - Cell recognition - glycoprotein indentification tags - membrane protein serve as identification tags that are specifically recognized by other cells.

Intercellular Joining - various cell junction - membrane protein of adjacent cells hook together to form various junction for interaction or sharing purpose.

Attachment - attach to cytoskeleton and extracellular matrix - some membrane proteins helps in maintaining the cell shape and stabilizes the location of proteins.