Cell Transport and Plasma Membrane

These flashcards cover key concepts related to the plasma membrane and various transport mechanisms across the cell membrane.

What is the plasma membrane also known as?

Cell membrane.

What does selectively permeable mean in the context of the plasma membrane?

It allows certain small particles to pass through easily while restricting large particles and ions.

What is the composition of the plasma membrane?

It is composed of phospholipids that form a bilayer.

What are the two regions of phospholipids?

A polar 'head' (hydrophilic) and a non-polar 'tail' (hydrophobic).

What are the two types of membrane proteins?

Peripheral proteins and integral proteins.

What is the function of peripheral proteins?

They are located on the interior or exterior surface of the membrane and are used for cell and hormone recognition.

How do integral proteins assist in cell transport?

They span the membrane and facilitate the passage of large substances across it.

What is passive transport?

The movement of substances across the plasma membrane without the expenditure of energy (ATP).

What are the three types of passive transport?

Diffusion, osmosis, and facilitated diffusion.

What is diffusion?

The movement of molecules from an area of high concentration to an area of low concentration.

What is facilitated diffusion?

The movement of molecules from high concentration to low concentration with the assistance of membrane proteins.

What is osmosis?

The movement of water from an area of low solute concentration to high solute concentration.

What are the three types of osmotic solutions?

Hypertonic, hypotonic, and isotonic.

What occurs during plasmolysis?

The cell shrinks and pulls away from the cell wall when plants are placed in hypertonic solutions.

What is turgor pressure?

The pressure against the cell wall in plants created when they are in hypotonic solutions.

What is active transport?

The movement of substances across a membrane against their concentration gradients, requiring energy (ATP).

What is the primary function of cell membrane pumps?

To move substances against their concentration gradient using energy.

What is endocytosis?

A process where cells ingest substances from the external environment using energy (ATP).

What is phagocytosis?

The movement of large particles into the cell, known as 'cell eating.'

What is pinocytosis?

The movement of fluids into the cell, known as 'cell drinking.'

What is exocytosis?

The movement of substances out of the cell through the fusion of vesicles with the plasma membrane.

What is equilibrium in the context of cell transport?

A state reached when all the molecules of a substance are equally distributed in a space.

Why is active transport necessary for maintaining concentration gradients?

It requires energy to maintain these unequal gradients.