endocrine signaling

Question: When A Signal Needs To Be Sent To Most Cells Throughout A Multicellular Organism, The Signal Most Suited For This Is A Scaffold. Hormone.

When cells respond to an extracellular signal, they most often convert the information from one form to another. This process is called: signal transduction.

Reversible bonding of signal molecules allows cells to become inactive and the receptor to become open again, allowing the cell to be able to respond to another signal.

The major types of signaling mechanisms that occur in multicellular organisms are paracrine, endocrine, autocrine, and direct signaling.

The three stages of cell communication (reception, transduction, and response) and how changes couls alter cellular responses. How a receptor protein recognizes signal molecules and starts transduction.

While most pathways share the same basic steps of cell signaling (reception, transduction, response, resetting), there are different pathways.

the signal that is being transduced is the information that a signaling molecule is bound to the cell surface receptor. information is transduced by way of sequential protein-protein interactions that change protein shapes causing them to function in a way that passes the signal along.

Gene expression. Many signaling pathways cause a cellular response that involves a change in gene expression. Gene expression is the process in which information from a gene is used by the cell to produce a functional product, typically a protein. It involves two major steps, transcription and translation.

Cells typically receive signals in chemical form via various signaling molecules. When a signaling molecule joins with an appropriate receptor on a cell surface, this binding triggers a chain of events that not only carries the signal to the cell interior, but amplifies it as well.

Terms in this set (32)

• signal is produced. – the signaling cell produces a particular type of extracellular signaling molecule.
• signal is received by the target cell.
• signal is transduced (extracellular signal is converted into an intracellular signal or response)

What are the four steps of signal transduction? (1) signal molecule binds to receptor that (2) activates a protein that (3) creates second messengers that (4) creates a response….Terms in this set (43)

• electrical.
• chemical.
• both electrical and chemical.

Cell signaling can be divided into 3 stages.

• Reception: A cell detects a signaling molecule from the outside of the cell.
• Transduction: When the signaling molecule binds the receptor it changes the receptor protein in some way.
• Response: Finally, the signal triggers a specific cellular response.

The following animation depicts a signal transduction pathway in a liver cell. The first step in epinephrine signaling occurs when the hormone binds to an epinephrine receptor on the cell surface. The hormone triggers the receptor to change shape, converting the receptor to its active form.

Three Stages of Cell Signaling

• Reception: A cell detects a signaling molecule from the outside of the cell.
• Transduction: When the signaling molecule binds the receptor it changes the receptor protein in some way.
• Response: Finally, the signal triggers a specific cellular response.

Examples are progesterone and testosterone, as well as thyroid hormones. They generally regulate transcription; or water soluble molecules that bind to receptors on the plasma membrane. They are either proteins like insulin and glucagons, or small, charged molecules like histamine and epinephrine.

Signal transduction pathways amplify the incoming signal by a signaling cascade using a network of enzymes that act on one another in specific ways to ultimately generate a precise and appropriate physiological response by the cell.

Which of these is responsible for initiating a signal transduction pathway? The attachment of a signal molecule to a plasma membrane receptor initiates a signal transduction pathway.

What role does a transcription factor play in a signal transduction pathway? It relays a signal from the cytoplasm to the plasma membrane. It activates relay proteins. By binding to DNA it triggers the transcription of a specific gene.

An important example of negative feedback is the control of blood sugar. After a meal, the small intestine absorbs glucose from digested food. Blood glucose levels rise. Increased blood glucose levels stimulate beta cells in the pancreas to produce insulin.

How many independent variables are there in a well-designed experiment? One, so you can determine a cause and effect relationship between the variable you are changing and the observed response.

A well-designed experiment includes design features that allow researchers to eliminate extraneous variables as an explanation for the observed relationship between the independent variable(s) and the dependent variable.

Experiments can have only one independent variable. If you want to know the effect of caffeine (or extra sleep or improved training) on your race time, you would have to design a second (or third or fourth) experiment.

1 Answer. There are an infinite number of variables in every real experiment!

Most experimental designs measures only one or two variables at a time. Any other factor, which could potentially influence the results, must be correctly controlled. Its effect upon the results must be standardized, or eliminated, exerting the same influence upon the different sample groups.

Controlling variables is important because slight variations in the experimental set-up could strongly affect the outcome being measured. For example, during the 1950s, a number of experiments were conducted to evaluate the toxicity in mammals of the metal molybdenum, using rats as experimental subjects.

Variables are just values that can change; a good experiment only has two changing variables: the independent variable and dependent variable. A control variable is another factor in an experiment; it must be held constant.