Receptors: Up and Down Regulation Flashcards

Questions and Answers

What is a receptor?

A chemical messenger

A component of DNA

A type of hormone

A protein on the surface of a cell (correct)

What happens when external substances bind to a receptor?

It directs the cell to do something, such as divide, die, or allow specific substances to enter or exit the cell.

What initiates the creation of a receptor protein in a cell?

The cell's DNA contains the instructions.

Receptors cannot be recycled into the cell after they have been expressed.

False Signup and view all the answers

What is down-regulation?

A decrease in the number of receptors on the cell membrane reduces sensitivity to a specific message. Signup and view all the answers

What is up-regulation?

An increase in the number of receptors on the cell membrane increases sensitivity to a message. Signup and view all the answers

How do cells recognize chemical signals?

A cell is a target for a chemical message if it contains functional receptors for that message. Signup and view all the answers

Which of the following are types of chemical messages?

All of the above Signup and view all the answers

What is the purpose of cell signaling?

To allow cells to receive and process external signals. Signup and view all the answers

Study Notes

Receptors

Proteins located on the cell surface that receive external chemical messengers.
Binding of substances to receptors directs cellular actions such as division, apoptosis, or material transport.

Life Cycle of Receptors

Receptors are synthesized based on DNA instructions within the cell.
Once created, receptors are expressed on the cell membrane, enabling the cell to respond to specific signals.

Down Regulation

Receptors can be internalized and recycled, resulting in fewer receptors on the cell membrane.
Reduction in receptors decreases cell sensitivity to specific messages, termed down-regulation.

Up Regulation

In response to weak signals, cells increase receptor production to enhance sensitivity, known as up-regulation.
The cell's heightened responsiveness occurs as more receptors for the message are present.

Cell Signal Recognition

Target cells possess specific functional receptors for chemical messages; without them, the cells cannot be influenced.
Analogy: Cells act like radios; they need tuned receivers to process signals effectively and respond accordingly.

Types of Chemical Messages

Chemical messages include hormones, neurotransmitters, cytokines, growth factors, cell recognition molecules, and toxins.
These messages originate from various systems: endocrine (hormones), nervous (neurotransmitters), immune (cytokines).

Cell Signaling

Cells must receive and process external signals to react to environmental changes.
They can receive multiple signals simultaneously and integrate this information into a cohesive response.

Description

Explore the fundamental concepts of receptors, including their definition and life cycle, through this set of informative flashcards. Perfect for students studying cellular biology and signal transduction. Test your knowledge on how receptors function in regulating cellular activities.