Bio 3711 Adaptations

Acclimation

Process through which organisms adjust their physiology to reach a new steady state (as a response to a change in a given environmental variable).

Regulators

Maintain constant parameters (ex. temperature, salt content) in the face of external change

Conformers

Allow parameters (ex. temperature, salt content) to change along with external values

Homeotherms

Regulate their body temperature, Body temperature is slightly higher than the ambient. Includes strong swimming fish.

Poikilotherms

Conform to the external temperature, includes all subtidal marine invertebrates and most fishes. Some intertidal marine invertebrates lower their body temperature through evaporation and circulation of body fluids.

Methods for reducing heat loss

Insulation, Vasoconstriction, Counter-current heat exchange

Counter-current heat exchange

warm and cold blood flow in opposite directions in two adjacent blood vessels

High Temperature and Protein Function

High Temperature: protein binding sites are enlarged and proteins can denature

Animals respond to high temperature by producing Heat shock Proteins (HSP) which protect 3D structure.

When there is extreme T damage, ubiquitin is produced (degrades damaged proteins).

Cold Temperature Adaptations

Increasing intracellular salt (lowers freezing temperature) or having antifreeze compounds in the body.

Osmosis

Movement of water in the direction of low to high solute concentration

Organic Osmolytes

Used in marine organisms to adjust to increasing salinity, can be used instead of ions to increase osmolarity in cells (e.g. glycerol, sucrose, certain amino acids, urea...)

Small organisms take up O2 through...

Diffusion

Larger polychaetes, molluscs and crustaceans take up O2 through...

Gills, Circulatory systems

Mammals take up O2 through...

Lungs

Burrowing species take up O2 through...

creating water currents within their burrows (bio-irrigation)

Responses to Low Oxygen

-->Anaerobic pathways

-->O2 is retained and transported into more demanding tissues and eventually activity levels are reduced (increased ventilation)

-->Oxygen binding pigments increase oxygen capacity