Tissues Are Strong and Resilient

Biological Strategy

Animals

AskNature Team

Image: Jawahar Swaminathan and MSD staff / European Bioinformatics Institute /

Modify Material Characteristics

The materials found in living systems are variable, yet often made from the same basic building blocks. For example, all insect exoskeletons consist of a material called chitin. Because material resources are limited, each material within or used by a given living system must frequently serve multiple purposes. Therefore, living systems have strategies to modify materials’ softness, flexibility, and other characteristics. To ensure survival, the benefits of these modifications must outweigh the living system’s energy and material expenditure to generate them. For example, spiders store the liquid components of spider silk in a gland, converting them into silk thread when needed. Some threads have different characteristics, such as elasticity and UV reflectance, than others.

Search this Function

Animals

Kingdom Animalia (“having breath or soul”): Mammals, reptiles, sponges, corals, insects, birds

This kingdom captures a staggering variety of life—from the smallest coral polyp to the largest elephant. Although animal body shapes and life histories vary, there are a few defining characteristics. Animals are heterotrophs, meaning they gain energy from eating other organisms, and have developed from single-celled ancestors to highly diversified and coordinated multicellular forms. Unlike plant and fungi cells that have rigid cell walls, animal cells are bound by more flexible combinations of proteins. Most animals have cells organized into tissues and are able to move within their environment.

Search this Living System

Tissues in human organ systems are strong and resilient partly due to the presense of fibulins, a family of proteins that leverage calcium binding to form strong fibers in connective tissue composites.

One of the key factors in the evolution of multicellular organisms is the "glue" that hold cells together to form functional tissues. This connective material needs to be strong enough to withstand the constant activity required of many organ systems, yet flexible enough to bounce back from common trauma. A set of s, called fibulins, appear to be key components of this connective composite material, particularly because of their ability to bind calcium ions. Calcium ion bonding contributes to strong protein fibers–the reinforcement constituents of these composites.

Last Updated August 23, 2016

References

Journal article

Fibulins: a versatile family of extracellular matrix proteins

Nature Reviews Molecular Cell Biology | 30/05/2003 | Rupert Timpl, Takako Sasaki, Günter Kostka, Mon-Li Chu

embedly preview

AskNature