Cell Transport

These flashcards review key concepts and definitions related to cell transport, including passive and active transport mechanisms, types of protein transport, and processes like endocytosis and exocytosis.

What is passive transport?

Movement of molecules across the cell membrane without the use of energy, going from high to low concentration.

What is active transport?

Movement of molecules against their concentration gradient, requiring energy input (ATP) to move from low to high concentration.

what is endocytosis?

Bulk transport into cell

bulk (One very large thing or many small things at once)

how do proteins involve with active transport move molecules across the membrane?

Use energy usually from ATP to change shape and pump molecules across the membrane from low concentration to high concentration

What are the two types of passive transport?

Simple diffusion and facilitated diffusion.

What characterizes simple diffusion?

Diffusion of small, hydrophobic and nonpolar molecules directly through the cell membrane. (CO2 / O2)

What molecules typically utilize facilitated diffusion?

Large, polar, and/or charged molecules that cannot easily diffuse through the membrane. (sugars / ions/amino acids)

What are channel proteins?

Transmembrane proteins that allow specific ions or molecules to pass through the membrane.

passive/ specific for molecule/ continous transport/ aquaporins/ do not change shape

What is the function of aquaporins?

Specialized channel proteins that facilitate water transport across the cell membrane.

What distinguishes carrier proteins from channel proteins?

Carrier proteins change shape to transport larger molecules across the membrane.

specific for molecules/ passive or active/ transport molecules one at a time

What is primary active transport?

Active transport using energy directly from ATP to move molecules.

What is secondary active transport?

Active transport that uses the energy from the concentration gradient of another molecule, rather than ATP. (atp used indirectly)

What are the three forms of endocytosis?

Phagocytosis, pinocytosis, and receptor-mediated endocytosis.

What is phagocytosis?

A process where a cell engulfs large particles or cells, also known as 'cellular eating.'

What is pinocytosis?

A process where a cell ingests droplets of fluid from its environment, also known as 'cellular drinking.'

What is receptor-mediated endocytosis?

Transport process where specific molecules are taken into the cell after they bind to receptors on the cell surface.

What is exocytosis?

The process by which substances are released outside the cell (bulk transport)