V0-morph
Encyclopedia
An V0-morph is an organism
that changes in shape during growth such that its surface area is proportional to its volume to the power 0, so its surface area is constant.
The reason why the concept is important in the context of the Dynamic Energy Budget
theory is that food (substrate) uptake is proportional to surface area, and maintenance to volume. The surface area that is of importance is that part that is involved in substrate uptake.
Biofilm
s on a flat solid substrate are examples of V0-morphs; they grow in thickness, but not in surface area that is involved in nutrient exchange. Other examples are dinophyta and diatom
s that have a cell wall that does not change during the cell cycle. During cell-growth, when the amounts of protein and carbohydrates increase, the vacuole shrinks. The outer membrane that is involved in nutrient uptake remains constant. At cell division, the daughter cells rapidly take up water, complete a new cell wall and the cycle repeats.
Rods (bacteria that have the shape of a rod and grow in length, but not in diameter) are a static mixture between a V0- and a V1-morph
, where the caps act as V0-morphs and the cylinder between the caps as V1-morph.The mixture is called static because the weight coefficients of the contributions of the V0- and V1-morph terms in the shape correction function
are constant during growth.
Crust
s, such as lichen
s that grow on a solid substrate, are a dynamic mixture between a V0- and a V1-morph, where the inner part acts as V0-morph, and the outer annulus as V1-morph.The mixture is called dynamic because the weight coefficients of the contributions of the V0- and V1-morph terms in the shape correction function
change during growth.The Dynamic Energy Budget
theory explains why the diameter of crusts grow linearly in time at constant substrate availability.
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
that changes in shape during growth such that its surface area is proportional to its volume to the power 0, so its surface area is constant.
The reason why the concept is important in the context of the Dynamic Energy Budget
Dynamic energy budget
The Dynamic Energy Budget theory aims to identify simple quantitative rules for the organization of metabolism of individual organisms that can be understood from basic first principles...
theory is that food (substrate) uptake is proportional to surface area, and maintenance to volume. The surface area that is of importance is that part that is involved in substrate uptake.
Biofilm
Biofilm
A biofilm is an aggregate of microorganisms in which cells adhere to each other on a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric substance...
s on a flat solid substrate are examples of V0-morphs; they grow in thickness, but not in surface area that is involved in nutrient exchange. Other examples are dinophyta and diatom
Diatom
Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons , fans , zigzags , or stellate colonies . Diatoms are producers within the food chain...
s that have a cell wall that does not change during the cell cycle. During cell-growth, when the amounts of protein and carbohydrates increase, the vacuole shrinks. The outer membrane that is involved in nutrient uptake remains constant. At cell division, the daughter cells rapidly take up water, complete a new cell wall and the cycle repeats.
Rods (bacteria that have the shape of a rod and grow in length, but not in diameter) are a static mixture between a V0- and a V1-morph
V1-morph
An V1-morph is an organism that changes in shape during growth such that its surface area is proportional to its volume to the power 1, so to its volume...
, where the caps act as V0-morphs and the cylinder between the caps as V1-morph.The mixture is called static because the weight coefficients of the contributions of the V0- and V1-morph terms in the shape correction function
Shape correction function
The shape correction function is a ratio of the surface area of a growing organism and that of an isomorph as function of the volume. The shape of the isomorph is taken to be equal to that of the organism for a given reference volume, so for that particular volume the surface areas are also equal...
are constant during growth.
Crust
Crust
Crust may refer to:* Crust * The Crust, television seriesPhysical sciences:* Crust , at least continent-wide structure* Soil crust, local biology-sensitive structureFood:* Crust, dense surface layer of bread...
s, such as lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s that grow on a solid substrate, are a dynamic mixture between a V0- and a V1-morph, where the inner part acts as V0-morph, and the outer annulus as V1-morph.The mixture is called dynamic because the weight coefficients of the contributions of the V0- and V1-morph terms in the shape correction function
Shape correction function
The shape correction function is a ratio of the surface area of a growing organism and that of an isomorph as function of the volume. The shape of the isomorph is taken to be equal to that of the organism for a given reference volume, so for that particular volume the surface areas are also equal...
change during growth.The Dynamic Energy Budget
Dynamic energy budget
The Dynamic Energy Budget theory aims to identify simple quantitative rules for the organization of metabolism of individual organisms that can be understood from basic first principles...
theory explains why the diameter of crusts grow linearly in time at constant substrate availability.
See also
- Dynamic energy budgetDynamic energy budgetThe Dynamic Energy Budget theory aims to identify simple quantitative rules for the organization of metabolism of individual organisms that can be understood from basic first principles...
- isomorphIsomorphAn isomorph is an organism that does not change in shape during growth. The implication is that its volume is proportional to its cubed length, and its surface area to its squared length...
- V1-morphV1-morphAn V1-morph is an organism that changes in shape during growth such that its surface area is proportional to its volume to the power 1, so to its volume...
- shape correction functionShape correction functionThe shape correction function is a ratio of the surface area of a growing organism and that of an isomorph as function of the volume. The shape of the isomorph is taken to be equal to that of the organism for a given reference volume, so for that particular volume the surface areas are also equal...