Lec3- Transmembrane And Membrane Transport Flashcards
Operates passively via concentration gradient
•diffusion
•channels
•carriers
Transmembrane and Membrane Transport
Transport of small, nonpolar molecules directly to the lipid bilayer
•Fat- soluble difuses easily
•Water- difuses slowly
Diffusion
Multipass proteins forming transmembrane pores
•ions/small molecules pass selectively
•open and close mechanism
•Aquaporins- water channel proteins
Channels
Transmembrane proteins that binds small molecules and translocate them across the membrane
*via conformal change
Carriers
Type of a carrier protein that utilize ATP to move
Pumps
Vesicular Transport
•Phagocytosis
•Pinocytosis
•Receptor-mediate endocytosis
Endocytosis
Vesicular Transport
•Constitutive Secretion
•Regulated Secretion
Exocytosis
Process by which cells TAKE IN substances from outside of the cell
•engulfing them in a vesicle
Endocytosis
Cell eating
•Extension from the cell of surface folds or pseudopodia
•Engulfs particles like bacteria and other foreign bodies
Phagocytosis
Cell drinking
•Forms folds or invaginates
•Contain a portion of extracellular fluid
•Formation of pinocytic vesicle
Pinocytosis
• Uses receptors to bind specific molecules (ligand)
• Invagination to create a vesicle or endosome
• now contains both receptor and ligand
Receptor Mediated Endocytosis
•Taking out / Release
•Movement of large molecules from inside to outside the cells
•Involves vesicular transport mechanism
Exocytosis
Products are released immediately after being synthesized
Constitutive Secretion
Release of products is signaled via stimuli or depending on the needs of the cells or body
Regulated Secretion
Process of membrane movement and recycling
Membrane Trafficking
Endocytosis
Part of cell membrane becomes visicles
Exocytosis
Vesicles returned to the cell surface
