Glossary
Cancer
A disease characterized by uncontrolled cell growth and division, often resulting from mutations in genes that regulate the cell cycle and signal transduction.
Example:
Skin cancer can arise when skin cells accumulate mutations that cause them to divide uncontrollably, forming malignant growths.
Cell Cycle
The ordered sequence of events that a cell passes through from the moment it is formed until it divides into two daughter cells.
Example:
Proper regulation of the cell cycle is crucial for growth and repair, ensuring that cells divide only when necessary.
Chemical Disruptions
Interference with normal cellular processes, particularly signal transduction pathways, caused by the presence of specific chemical substances.
Example:
Exposure to certain environmental pollutants can cause chemical disruptions in hormone signaling, affecting development.
Denatured Proteins
Proteins that have lost their specific three-dimensional structure due to external stressors like extreme temperature or pH, rendering them non-functional.
Example:
If you put an enzyme in boiling water, it will become denatured proteins and lose its ability to catalyze reactions.
Inhibitors
Molecules that decrease the activity of an enzyme or block the binding of a ligand to its receptor, thereby preventing or reducing a biological response.
Example:
Many allergy medications work as inhibitors by blocking histamine receptors, preventing the allergic reaction.
Insulin
A hormone produced by the pancreas that plays a key role in regulating blood glucose levels by signaling cells to absorb glucose from the bloodstream.
Example:
After eating a sugary snack, your body releases insulin to help move the glucose from your blood into your cells for energy or storage.
Ligand
A molecule that binds specifically to another molecule, typically a receptor protein, to initiate a biological response.
Example:
Neurotransmitters like dopamine act as ligands that bind to specific receptors on nerve cells, transmitting signals in the brain.
Mutation
A permanent alteration in the DNA sequence of an organism's genome. These changes can affect protein structure and function, impacting cellular processes.
Example:
A mutation in the gene for a transport protein could prevent a cell from taking in essential nutrients.
Neurotoxins
Substances that are poisonous or destructive to nerve tissue, often by interfering with specific signal transduction pathways in the nervous system.
Example:
The venom of a black widow spider contains neurotoxins that cause an uncontrolled release of neurotransmitters, leading to muscle spasms.
Receptor
A protein, usually located on the cell surface or inside the cell, that binds to a specific ligand and initiates a cellular response.
Example:
The olfactory receptors in your nose bind to odor molecules, allowing you to smell different scents.
Signal Transduction Pathway
A series of molecular events where a cell converts an extracellular signal into a specific intracellular response, often involving a cascade of molecular interactions.
Example:
When a growth factor binds to a cell, it initiates a complex signal transduction pathway that ultimately tells the cell to divide.
Type 1 Diabetes
An autoimmune condition where the body's immune system mistakenly attacks and destroys the insulin-producing cells in the pancreas, leading to an absolute lack of insulin.
Example:
Individuals with Type 1 Diabetes must regularly inject insulin because their bodies cannot produce this vital hormone.
Type 2 Diabetes
A metabolic disorder characterized by insulin resistance, where the body's cells do not respond effectively to insulin, often combined with insufficient insulin production.
Example:
In Type 2 Diabetes, muscle and liver cells may not 'hear' the insulin signal to take up glucose, leading to elevated blood sugar levels.
Unregulated Cell Division
Cell division that occurs without proper control mechanisms, leading to an excessive and uncontrolled proliferation of cells.
Example:
The rapid and uncontrolled growth of a tumor is a prime example of unregulated cell division.