Related Concept Videos

Carbon Skeletons01:12

Carbon Skeletons

Life on Earth is carbon-based, as all macromolecules that make up living organisms contain carbon atoms. All organic compounds have a carbon backbone. Each carbon atom is tetravalent and can bond with four other atoms, making it an extraordinarily flexible component of biological molecules. Because carbon’s valence electrons are stable, it rarely becomes an ion. As the carbon chain increases in length, structural modifications such as ring structures, double bonds, and branching side chains...
Life Histories01:29

Life Histories

Constrained by limited energy and resources, organisms must compromise between offspring quantity and parental investment. This trade-off is represented by two primary reproductive strategies; K-strategists produce few offspring but provide substantial parental support, whereas r-strategists produce much progeny that receives little care. These strategies are related to an organism’s survival likelihood across its lifespan, which is represented by a survivorship curve. Three general types of...
Le Chatelier's Principle: Changing Concentration02:27

Le Chatelier's Principle: Changing Concentration

A system at equilibrium is in a state of dynamic balance, with forward and reverse reactions taking place at equal rates. If an equilibrium system is subjected to a change in conditions that affects these reaction rates differently (a stress), then the rates are no longer equal and the system is not at equilibrium. The system will subsequently experience a net reaction in the direction of a greater rate (a shift) that will re-establish the equilibrium. This phenomenon is summarized by Le...
Professional Values01:29

Professional Values

Nurses are responsible for caring for patients during birth, death, illness, and healing. Professional values guide the decisions and actions that nurses make in their careers. If nurses know the decisions and actions to take, providing patients with exceptional care is possible.
The values that are the foundation of the nursing profession are altruism, autonomy, human dignity, and social justice.
First, altruism refers to the concern for the welfare and well-being of others without personal...
Cadherins in Tissue Organization01:19

Cadherins in Tissue Organization

The cadherins are a superfamily of cell adhesion molecules comprising over 180 variants, with specific tissues expressing a particular combination of cadherin types. Cadherins generally exhibit homophilic binding; i.e., cadherins on one cell bind to cadherins of the same or closely related type on another cell. Thus, cells of the same type have a specific affinity to bind to each other and sort themselves into clusters to form tissues.
Cell Sorting During Development
Cell sorting plays an...
Forgetting01:21

Forgetting

Forgetting is an intrinsic aspect of human memory, characterized by the gradual loss or inaccessibility of information over time. Hermann Ebbinghaus, a pioneering psychologist, extensively studied this phenomenon and formulated the forgetting curve. This curve illustrates that memory loss occurs rapidly immediately after learning and then decelerates over time. Several mechanisms contribute to forgetting, including encoding failure, storage decay, retrieval failure, and interference.
Encoding...