Cell Transport Overview

Flashcards created from lecture notes on cell transport focus on key concepts like homeostasis, feedback mechanisms, types of transport, and definitions of relevant terms.

What is homeostasis?

The need of an organism to stay stable by regulating internal conditions.

What is a dynamic equilibrium?

A condition that isn’t always the same, but where internal conditions stay within a range.

What is a stimulus?

A change in the environment that requires a response from the organism.

What is the feedback mechanism?

A process that uses the output of a system to signal a change in input to stabilize or amplify a response.

What is a positive feedback loop?

A process where the output intensifies the response, leading to amplification.

Give an example of a positive feedback loop.

Human childbirth, where contractions lead to hormone release, causing more contractions.

What is a negative feedback loop?

A process where the output causes a counter response to return to a set point.

Give an example of a negative feedback loop.

Human body temperature regulation.

What does selectively permeable mean in relation to the cell membrane?

It means the cell membrane is picky about what goes in and out.

What is passive transport?

The movement of molecules from high to low concentration without using energy.

What is active transport?

The movement of molecules from low to high concentration using energy (ATP).

Define solute.

What gets dissolved in a solution, e.g., lemonade powder.

Define solvent.

The substance that does the dissolving, e.g., water.

What is osmosis?

The diffusion of water across a cell membrane.

What happens in a hypertonic solution?

Water moves out of the cell, causing it to shrivel.

What happens in a hypotonic solution?

Water moves into the cell, causing it to swell.

What does isotonic mean?

Solutions have identical water concentration to the cell's cytoplasm, and the cell stays the same.

What is molecular pumping?

Using energy to pump molecules against their concentration gradient through a protein channel.

What is endocytosis?

A process that uses vesicles to move large particles into the cell.

What is exocytosis?

A process that uses vesicles to export materials out of the cell.

How does facilitated diffusion help maintain homeostasis?

It regulates blood sugar levels by allowing glucose to enter cells.

How does the cell membrane help maintain homeostasis?

By controlling the movement of substances in and out of the cell.