Transportation in the cell membrane

This flashcard looks at transportation in the cell membrane

Integral glycoproteins

________ bind a solute and undergo a conformational change to translocate the solute across the membrane.

Pinocytosis

________- The process by which liquids /dissolved substances are ingested (allows faster entry than via protein channels)

intracellular vesicle

The invagination is then sealed off to form a(n) ________ containing the material.

Osmosis

________ is essentially the diffusion of free water molecules and hence occurs in regions of low solute concentration.

Carrier proteins

________ will only bind a specific molecule via an attachment similar to an enzyme- substrate interaction.

process of exocytosis

The ________ adds vesicular phospholipids to the cell membrane, replacing those lost when vesicles are formed via endocytosis.

Phagocytosis

________- The process by which solid substances are ingested (usually to be transported to the lysosome)

Materials

________ move via vesicles from the internal cis face of the Golgi to the externally oriented trans face.

Water

________ is considered the universal solvent- it will associate with, and dissolve, polar or charged molecules (solutes)

concentration

At a higher solute ________, there are fewer free water molecules in the solution as water is associated with the solute.

endoplasmic reticulum

The ________ is a membranous network that is responsible for synthesizing secretory materials.

Channel proteins

________ are ion- selective and may be gated to regulate the passage of ions in response to certain stimuli.

large substances

The process by which ________ (or bulk amounts of small substances) exit the cell without crossing the membrane.

Vesicles

________ (typically derived from the Golgi) fuse with the plasma membrane, expelling their contents into the extracellular environment.

Rough ER

________ is embedded with ribosomes and synthesizes proteins destined for extracellular use.

extracellular fluid

The vesicle will fuse with the cell membrane and its materials will be expelled into the ________.

Smooth ER

________ is involved in lipid synthesis and also plays a role in carbohydrate metabolism.

Carrier proteins

________ may move molecules against concentration gradients in the presence of ATP (i.e.

Materials

________ are transported from the ER when the membrane bulges and then buds to create a vesicle surrounding the material.

large substances

The process by which ________ (or bulk amounts of smaller substances) enter the cell without crossing the membrane.

Channel proteins

________ have a much faster rate of transport than carrier proteins.

Carrier proteins

________ have a much slower rate of transport than channel proteins (by an order of- 1, 000 molecules per second)

Summary

This note goes into detail about how particles move across membranes

Water is considered the universal solvent

it will associate with, and dissolve, polar or charged molecules (solutes)

This process is mediated by two distinct types of transport proteins

channel proteins and carrier proteins

Phagocytosis

The process by which solid substances are ingested (usually to be transported to the lysosome)

Pinocytosis

The process by which liquids / dissolved substances are ingested (allows faster entry than via protein channels)

How Does Active transport generate energy to move molecules against a concentration gradient

This energy may either be generated by:

The direct hydrolysis of ATP (primary active transport)
Indirectly coupling transport with another molecule that is moving along its gradient (secondary active transport)

How are protein pumps used during active transport?

A specific solute will bind to the protein pump on one side of the membrane
The hydrolysis of ATP (to ADP + Pi) causes a conformational change in the protein pump
The solute molecule is consequently translocated across the membrane (against the gradient) and released