hemipelagic sediments
150
hemipelagic sediments -7deep-sea sediments.
hemocoel body cavity, actually an expanded part of the blood system, containing blood. Well developed in Arthropoda and Mollusca, where the coelom is
small.
hemocyanin (haemocyanin) large, colorless molecules occurring in esp. Crustacea
and Mollusca as oxygen-binding protein. In hemocyanin, the copper is bound
to the protein and does not occur in a functional group; it always occurs dissolved in the plasma.
hemoglobin (haemoglobin), the red coloring matter of blood. The pigment consists of an iron-porphyrin (heme, haeme) coupled to a protein (globin).
Hemoglobins consist of variable numbers of unit molecules, each unit containing one heme and its associated protein. The unit molecular weight for
vertebrates is ca. 16 10 3 ; the hemoglobins of higher vertebrates have four
units and are intracellular (red blood corpuscles or erythrocytes). Heme is
a protoporphyrin consisting of four pyrroles with an iron atom in the center. Hemoglobin is generally associated with oxygen binding, but also possesses an exceptional capacity to react with a variety of other substances,
such as organic and inorganic ions (salts) and dissolved gases. The function
of hemoglobin depends on the reversible combination of the ferrous (Fez+)
iron with oxygen (oxygenation) in proportion to the partial pressure of oxygen. 0z combines with each iron atom. The iron-protoporphyrin heme coupled with specific proteins is the best-known oxygen-carrying pigment. The
protein part or globin varies considerably in size, amino acid composition,
charge, solubility, and other physical properties from animal to animal.
Hemoglobins may be extracellular in body fluids, or intracellular in special
corpuscles, or occur in tissue cells (particularly in muscle myoglobin, and
nerve). There are many different hemoglobins with different proteins and
similar hemes.
Henry's law empirical relation stating that the vapour pressure of a substance is
linearly proportional to its concentration in solution. The constant of proportionality is known as the Henry coefficient. The validity of Henry's law is
limited to dilute solutions.
herbicide a pesticide to combat plant pests; a chemical substance for killing
plants, especially weeds.
herbivores organisms that eats plants. In the sea, herbivores feed predominantly by grazing on phytoplankton. Most zooplankton and zoobenthos species are
basically herbivores, though certain amounts of detritus and Bacteria ingested
with the algae make a clear distinction of true herbivores difficult. -7grazing.
150
hemipelagic sediments -7deep-sea sediments.
hemocoel body cavity, actually an expanded part of the blood system, containing blood. Well developed in Arthropoda and Mollusca, where the coelom is
small.
hemocyanin (haemocyanin) large, colorless molecules occurring in esp. Crustacea
and Mollusca as oxygen-binding protein. In hemocyanin, the copper is bound
to the protein and does not occur in a functional group; it always occurs dissolved in the plasma.
hemoglobin (haemoglobin), the red coloring matter of blood. The pigment consists of an iron-porphyrin (heme, haeme) coupled to a protein (globin).
Hemoglobins consist of variable numbers of unit molecules, each unit containing one heme and its associated protein. The unit molecular weight for
vertebrates is ca. 16 10 3 ; the hemoglobins of higher vertebrates have four
units and are intracellular (red blood corpuscles or erythrocytes). Heme is
a protoporphyrin consisting of four pyrroles with an iron atom in the center. Hemoglobin is generally associated with oxygen binding, but also possesses an exceptional capacity to react with a variety of other substances,
such as organic and inorganic ions (salts) and dissolved gases. The function
of hemoglobin depends on the reversible combination of the ferrous (Fez+)
iron with oxygen (oxygenation) in proportion to the partial pressure of oxygen. 0z combines with each iron atom. The iron-protoporphyrin heme coupled with specific proteins is the best-known oxygen-carrying pigment. The
protein part or globin varies considerably in size, amino acid composition,
charge, solubility, and other physical properties from animal to animal.
Hemoglobins may be extracellular in body fluids, or intracellular in special
corpuscles, or occur in tissue cells (particularly in muscle myoglobin, and
nerve). There are many different hemoglobins with different proteins and
similar hemes.
Henry's law empirical relation stating that the vapour pressure of a substance is
linearly proportional to its concentration in solution. The constant of proportionality is known as the Henry coefficient. The validity of Henry's law is
limited to dilute solutions.
herbicide a pesticide to combat plant pests; a chemical substance for killing
plants, especially weeds.
herbivores organisms that eats plants. In the sea, herbivores feed predominantly by grazing on phytoplankton. Most zooplankton and zoobenthos species are
basically herbivores, though certain amounts of detritus and Bacteria ingested
with the algae make a clear distinction of true herbivores difficult. -7grazing.