Biology: Cell Transport Flashcards

Questions and Answers

What are the three types of cell transport?

simple diffusion, facilitated diffusion, active transport

What is simple diffusion?

A passive process in which small, nonpolar molecules move freely down their concentration gradients through a cell membrane without the help of transport proteins.

What is osmosis?

The diffusion of solvent particles (H2O) across a semipermeable membrane from an area of higher solvent concentration to an area of lower solvent concentration.

What is a hypotonic solution?

When the concentration of solute particles outside the cell is lower than the concentration in the cytosol, causing H2O to flow into the cell. Signup and view all the answers

What is an isotonic solution?

A solution whose solute concentration is equal to the solute concentration inside a cell. Signup and view all the answers

What is a hypertonic solution?

When the concentration of solute particles inside the cell is lower than the concentration in the cytosol, causing H2O to flow out of the cell. Signup and view all the answers

What is facilitated diffusion?

The spontaneous passage of large, polar molecules and ions, bound to specific carrier proteins, across a biological membrane down their concentration gradients. Signup and view all the answers

What is active transport?

Transport of a solute across a cell membrane against the concentration gradient, which always requires energy. Signup and view all the answers

What is endocytosis?

An active transport process in which a cell engulfs materials with a portion of its cell membrane and releases those contents as vesicles into the cell. Signup and view all the answers

What is pinocytosis?

A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes. Signup and view all the answers

What is phagocytosis?

A type of endocytosis in which large molecules are taken up by the cell. Signup and view all the answers

What is exocytosis?

An active transport process of exporting substances from a cell by a vesicle fusing with the plasma membrane and releasing its contents outside the cell. Signup and view all the answers

Study Notes

Types of Cell Transport

Three main types of cell transport: simple diffusion, facilitated diffusion, and active transport.

Simple Diffusion

Passive process requiring no energy, allowing small, nonpolar molecules like O2 and CO2 to move freely through the cell membrane.
Movement occurs down the concentration gradient from high to low concentrations.

Osmosis

The specific diffusion of solvent particles, primarily water (H2O), across a semipermeable membrane.
Occurs from an area of higher solvent concentration to lower solvent concentration.

Hypotonic Solution

Defined by a lower concentration of solute particles outside the cell compared to inside.
Results in the flow of water into the cell, potentially causing it to swell.

Isotonic Solution

Characterized by equal solute concentration inside and outside the cell.
No net movement of water occurs, maintaining cell stability.

Hypertonic Solution

Higher concentration of solute particles outside the cell compared to inside.
Causes water to flow out of the cell, which may lead to cell shrinkage.

Facilitated Diffusion (Passive Transport)

Involves the spontaneous passage of large, polar molecules and ions through specific carrier proteins.
Occurs down the concentration gradient without the need for energy.

Active Transport

Transport mechanism that moves solutes against the concentration gradient, requiring energy (ATP).
Example includes glucose filtration in kidneys.

Endocytosis

Active transport process in which the cell engulfs materials using its membrane to form vesicles, transporting contents into the cell.

Pinocytosis

A specific type of endocytosis where the cell takes in extracellular fluid and dissolved solutes.

Phagocytosis

Type of endocytosis for uptake of large molecules, performed by certain immune cells (e.g., macrophages, neutrophils).
Often involves binding a substrate to receptors to initiate ingestion.

Exocytosis

Active process for exporting substances from the cell by vesicles that fuse with the plasma membrane.
Important for processes in the nervous system and intracellular signaling.

Description

Test your knowledge on cell transport mechanisms with these flashcards. Learn about simple diffusion, facilitated diffusion, and active transport. This quiz serves as a quick review tool for students studying biology concepts related to cellular processes.