BIO 1010 Chapter 9: Cell Communication and Apoptosis

This flashcard set covers the fundamental concepts of cell signaling pathways, the stages of cellular response, and the detailed process of programmed cell death (apoptosis) from Chapter 9 of BIO 1010.

What is the general "Big Pattern" of cell communication?

Signal comes in -> receptor activates -> message gets passed inside -> cell responds.

Distinguish between incoming and outgoing signals in cell communication.

Incoming signals are received by a cell, while outgoing signals are sent by a cell to communicate with others.

What are some examples of incoming signals that impact cells?

Hormones, neurotransmitters, growth factors, chemical signals, light, temperature changes, or signals from nearby cells.

Why is cell signaling essential for a cell's survival?

It allows cells to respond to internal and external environment changes, maintain homeostasis, grow, divide, repair damage, and respond to threats.

Define cellular response.

The change a cell makes after receiving and processing a signal.

What is direct contact signaling?

A pathway where cells physically touch or are connected to pass signals directly, such as gap junctions in animal cells.

What is paracrine signaling?

A pathway where a cell releases a signal that affects nearby cells, such as growth factors helping repair tissue.

Define synaptic signaling.

A pathway where a nerve cell releases a neurotransmitter across a synapse to a target cell, such as a muscle cell.

What is endocrine signaling?

A pathway where hormones travel through the bloodstream to distant target cells, such as insulin affecting body cells.

Define autocrine signaling.

A pathway where a cell releases a signal that binds to receptors on itself, such as an immune cell signaling itself to increase activity.

What occurs during the receptor activation/reception stage?

A signaling molecule, or ligand, binds to a specific receptor, causing it to change shape or become activated and start the process.

What is signal transduction?

The stage where the message is passed through the cell, often via relay proteins and enzymes like protein kinases, and potentially amplified.

What are the three main types of cellular responses?

1. Change in gene expression (turning genes on/off); 2. Change in enzyme activity or metabolism; 3. Change in cell behavior (movement, growth, division, secretion, or apoptosis).

Define apoptosis.

Programmed cell death; an organized process where a cell safely breaks itself down without causing inflammation or damage to nearby cells.

What physical changes happen to a cell undergoing apoptosis?

The cell shrinks and rounds, DNA is destroyed, and the plasma membrane forms bulges called blebs before the cell breaks into pieces.

What is a bleb?

A bubble-like bulge in the plasma membrane that forms during apoptosis.

What are the three main reasons why apoptosis occurs?

1. Development (e.g., removing webbing); 2. Cell damage or infection; 3. Maintaining cell numbers or homeostasis.

What triggers the extrinsic pathway for apoptosis?

An external death signal where a death ligand binds to a death receptor on the cell surface.

What is the role of caspases in the extrinsic apoptosis pathway?

They are enzymes activated by adaptor proteins (which bind to activated death receptors) that carry out the process of apoptosis.

In the memory pattern "R-T-R", what does each letter represent?

Reception, Transduction, Response.