AP Biology Chapter 11

Why do cells need to communicate?

Cells need to communicate for the proper functioning and continual evolving of the cell system as a whole. The cells must work together to coordinate activities that develop an organism from a fertilized egg to a fully functioning organism that can surviv

What are three ways cells communicate?

Three ways cells can communicate are through direct contact, local chemical signaling, and long-distance hormonal signaling. In direct contact, cells bind together by gap junctions in animals or plasmodesmata in plants. It can also bind by cell-cell recog

Explain what happens during the three phases of signal transduction.

Signal transduction is the process by which a signal on a cell's surface is converted to a specific cellular response. The three phases of signal transduction are reception, transduction, and response.
1. Reception-a protein at the cell surface detects ch

What is the purpose of second messengers?

Second messengers are molecules that relay signals received at receptors on the cell surface � such as the arrival of protein hormones, growth factors, etc. � to target molecules in the cytosol and/or nucleus.
Second messenger systems are a means of trans

Diagram the epinephrine signaling pathway? Diagram signal reception, transduction and response:

When our senses perceive an environmental stress such as danger or a threat, cells in the nervous and endocrine systems work closely together to prepare the body for action. Often referred to as the fight or flight or stress response, this remarkable exam

Define Quorum Sensing, identify the organisms that it occurs in and explain how cellular signaling is used in it:

is the regulation of gene expression in response to fluctuations in cell-population density. Quorum sensing bacteria produce and release chemical signal molecules called autoinducers that increase in concentration as a function of cell density. Autoinduce

Define Mating in Yeasts, identify the organisms that it occurs in and explain how cellular signaling is used in it:

Yeast cells identify their mates by chemical signaling. There are two sexes: a and A. Cells of mating type a secrete a signaling molecule called a factor, which can bind to specific receptor proteins on nearby A cells. At the same time, A cells secrete A

Define Apoptosis, identify the organisms that it occurs in and explain how cellular signaling is used in it:

When a cell is damaged, superfluous, or potentially dangerous to an organism, a cell can initiate a mechanism to trigger programmed cell death, or apoptosis. Apoptosis allows a cell to die in a controlled manner that prevents the release of potentially da

How would methylation of a receptor protein affect the signaling process?

Methylation is the addition of a (CH3) methyl group to a molecule (most likely DNA). This methylation is commonly used to fix genes in the "off" position. So, if the receptor protein was methylated, the signaling molecule's message would have no effect on

How is a signal amplified?

A signal is amplified by elaborate enzyme cascades that also amplify the cell's response. At each step, the number of activated products is greater than the the previous step. A signal may reach a cell in the form of a single hormone molecule. Inside the

Why do you think cellular signaling pathways and mechanisms are so universal among life's domains?

Cell signaling is part of a complex system of communication that governs basic activities of cells and coordinates cell actions. The ability of cells to perceive and correctly respond to their microenvironment is the basis of development, tissue repair, a