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Adhesion: The adherence of molecules to the walls of conducting tubes, as in plants.
Adhesion is the tendency of dissimilar particles and/or surfaces to cling to one another
(cohesion refers to the tendency of similar or identical particles/surfaces to cling to one
another). The forces that cause adhesion and cohesion can be divided into several
different types. The intermolecular forces responsible for the function of various kinds of
stickers and sticky tape fall into the categories of chemical adhesion, dispersive
adhesion, and diffusive adhesion. In addition to the cumulative magnitudes of these
intermolecular forces, there are certain emergent mechanical effects that will also be
discussed at the end of the article.
Archaean eon: One of two domains of prokaryotes; archaeans have some unique
molecular and biochemical traits, but they also share some traits with Bacteria and other
traits with Eukarya.
Biopolymers: are polymers produced by living organisms. Cellulose, starch, chitin,
proteins, peptides, DNA and RNA are all examples of biopolymers, in which the
monomeric units, respectively, are sugars, amino acids, and nucleotides.
Carbon: Carbon ( / ˈ k ɑ r b ə n / ) is the chemical element with symbol C and atomic
number 6. As a member of group 14 on the periodic table, it is nonmetallic and
tetravalent—making four electrons available to form covalent chemical bonds. There are
three naturally occurring isotopes, with 12
C and 13
C being stable, while 14
C is radioactive,
decaying with a half-life of about 5730 years. Carbon is one of the few elements
known since antiquity. The name "carbon" comes from Latin language carbo, coal.
Central dogma: The central dogma of molecular biology was first articulated by
Francis Crick in 1958 and re-stated in a Nature paper published in 1970:
The central dogma of molecular biology deals with the detailed residue-by-residue
transfer of sequential information. It states that information cannot be transferred back
from protein to either protein or nucleic acid.
In other words, 'once information gets into protein, it can't flow back to nucleic acid.'
The dogma is a framework for understanding the transfer of sequence information
between sequential information-carrying biopolymers, in the most common or general
case, in living organisms. There are 3 major classes of such biopolymers: DNA and
RNA (both nucleic acids), and protein. There are 3×3 = 9 conceivable direct transfers of
information that can occur between these. The dogma classes these into 3 groups of 3:
3 general transfers (believed to occur normally in most cells), 3 special transfers
(known to occur, but only under specific conditions in case of some viruses or in a
laboratory), and 3 unknown transfers (believed never to occur). The general transfers
describe the normal flow of biological information: DNA can be copied to DNA (DNA
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replication), DNA information can be copied into mRNA, (transcription), and proteins
can be synthesized using the information in mRNA as a template (translation).
Chemical evolution: Chemical evolution may refer to:
•Nucleosynthesis , the creation of chemical elements in the universe either through
the Big Bang, or supernovae
•Abiogenesis , the transition from nonliving elements to living systems
•Molecular evolution , evolution at the scale of molecules
Cohesion: Cohesion (n. lat. cohaerere "stick or stay together") or cohesive attraction
or cohesive force is a physical property of a substance, caused by the intermolecular
attraction between like-molecules within a body or substance that acts to unite them.
Mercury exhibits more cohesion than adhesion
Water, for example, is strongly cohesive as each molecule may make four hydrogen
bonds to other water molecules in a tetrahedral configuration. This results in a relatively
strong Coulomb force between molecules. Van der Waals gases such as methane,
however, have weak cohesion due only to Van der Waals forces that operate by
induced polarity in non-polar molecules.
Cohesion, along with adhesion (attraction between unlike molecules), helps explain
phenomena such as meniscus,
Emergence: A termite "cathedral" mound produced by a termite colony: a classic
example of emergence in nature.
Snowflakes forming complex symmetrical patterns is an example of emergence in a
In philosophy, systems theory, science, and art, emergence is the way complex
systems and patterns arise out of a multiplicity of relatively simple interactions.
Emergence is central to the theories of integrative levels and of complex systems
Evaporation: Evaporation is a type of vaporization of a liquid, that occurs only on the surface
of a liquid. The other type of vaporization is boiling, that instead occurs on the entire mass of the
liquid. Evaporation is also part of the water cycle.
Evaporation is a type of phase transition; it is the process by which molecules in a liquid state
(e.g. water) spontaneously become gaseous (e.g. water vapor). Generally, evaporation can be
seen by the gradual disappearance of a liquid from a substance when exposed to a significant
volume of gas. Vaporization and evaporation however, are not entirely the same processes
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