Abiogenesis
...n (referred to here as "Aristotelian abiogenesis"
for clarity) held that living organisms could be "born...could be killed by boiling. His work paved the way
for Louis Pasteur.
It was due chiefly to Louis Past...y of the manipulations necessary, made it possible
for a very long time to be doubtful as to the applicat...
Absorption spectrum
...frequencies, passing through a sample of cold gas.
for any collection of atoms or molecules , there ar...ific amounts of energy required to change state;
for individual atoms, these correspond to an electron... are particular to particular elements, and allows
for identification of elements present in stars and ot...
Coenzyme A
... by choline acetyltransferase . Its main task is conveying the carbon atoms within the acetyl group to the citric acid cycle to be oxidized
for energy production.
The conversion of pyruvate into Acetyl-CoA is referred to as the Pyruvate Dehydrogenase Reaction. It is catalyzed by an enzyme-...
Actin
... cell . Actin filaments provide mechanical support
for the cell, determine the cell shape, enable cell mo... in ADP-actin stimulates the exchange of bound ADP
for ATP, leading to more ATP-actin units. This rapid turnover is important
for the cells movement.
The protein cofilin binds t...
Activation energy
... is often used to denote the minimum energy needed
for a specific chemical reaction to occur.
for a reaction to occur between two colliding molecule...ion is overcome and the molecules get close enough
for attractions between the molecules to cause a rearr...
Active transport
...on of flow; but here, both solutes move in the same direction across the membrane. An example is the glucose symporter, which cotransports two sodiums
for every molecule of glucose it imports into the cell.
See also
Ion channel
...
Adaptive radiation
...when a species can survive in an environment that was unreachable before.
for example, the Darwin's finches on the Galapagos islands developed from a...ion sometimes adaptive radiation of humans is imagined. This often makes
for interesting multi-species worlds .
...
Adenosine triphosphate
...
for other uses of the initials ATP, see ATP (disambig... beta, and gamma phosphates. The biochemical name
for ATP is 9--D-ribofuranosyladenine-5'-triphosphate.
... chloroplasts by photosynthesis .
The main fuels
for ATP synthesis are glucose and fatty acids . Ini...
Albinism
...ght coming from the sun (see human skin color
for more information). People with albinism lack this ...ike in some animals, and the human eye is too deep
for the pupil to appear red rather than black.
Growt...t the zoo in October 2002 and died in August 2004.
for many years, a unique albino gorilla named Floqu...
Affinity chromatography
...with the target molecule (ie the molecule targeted
for purification) becoming trapped on a solid or stati...ng and elution steps can be omitted or used simply
for analytical purposes.
Specific Uses
Affinity... the most common use of affinity chromatography is
for the purification of recombinant proteins. Essentia...
Alcohol
...rogen and/or carbon atoms. The general formula
for a simple alcohol containing no rings is C n H 2n+...ohols are derived from natural fats and oils ,
for example lauryl alcohol (1-dodecanol, 12 carbons) o...ethanol is commercially produced this way, chiefly
for fuel and drink . Other alcohols are generally ...
Albumin
... You may be looking
for albumen , or egg white.
Albumin is a blood plasma protein that is...ood plasma are referred to collectively as globulin .
Albumin is essential
for maintaining the oncotic pressure needed
for proper distribution of body ...
Alexander Fleming
...hfield in Ayrshire , Scotland and was schooled
for two years at the Academy in Kilmarnock . He later...y's after the war with renewed energy in searching
for an improved antiseptic.
Both of Fleming's discov...ology in 1929 .
Fleming worked with the mould
for some time, but refining and growing it was a diffi...
Allele
...osition) on a chromosome . An example is the gene
for blossom color in many species of flower - a sing... have the same allele - is said to be homozygous
for that gene. An organism which has two different all...nt" allele will determine what trait is expressed.
for example, in the case of blossom color, if the "red...
Alfred Russel Wallace
...is family lost their remaining property. He worked
for his older brother William in his surveying busines...lter Bates (whom he had met in Leicester ), left
for Brazil to collect specimens in the Amazon Rainf...y the same as the theory that Darwin had worked on
for twenty years, but had yet to publish. Darwin wrot...
Allostery
...sume the R state, thereby enhancing their affinity
for substrate.
Sequential model
The sequentia...n the binding of one ligand decreases the affinity
for substrate at other active sites.
for example, when 2,3-BPG binds to a regulatory site...
Alga
...red a natural grouping, but the term is still used
for convenience. The study of algae is called phycolo...rms, called phytoplankton , provide the food base
for marine food chains . Phytoplankton can be presen...rmful Algal Blooms - "Red tide" - National Office
for Marine Biotoxins and Harmful Algal Blooms, USA.
...
Allele frequency
...by other variants the gene, of which there may be one or many.
Note that
for diploid genes, however, the proportion of individuals that carry this all... binomial theorem will apply: 32% of the population will be heterozygous
for the allele (i.e. carry one copy of that allele and one copy of another in e...
Allostery
...sume the R state, thereby enhancing their affinity
for substrate.
Sequential model
The sequentia...n the binding of one ligand decreases the affinity
for substrate at other active sites.
for example, when 2,3-BPG binds to a regulatory site...
Alternative splicing
... information structure:
A DNA sequence coding
for the pre-mRNA
An additional DNA code or other re...pt. However, the intron must be properly encoding
for amino acids . The intron's code must be properly...ics
Alternative splicing is of great importance
for genetics it means that the old idea of one DNA seq...
Amine
...ather than an amine.
See the Category:Amines
for a list of types of amine and some real examples of... act as bases and are reasonably strong (see table
for examples of conjugate acid K a values). The nitro...ts.
See also
IUPAC nomenclature
for the official naming rules...
Ames test
... genetics , generally genetic toxicology , to test
for mutagenic properties of a chemical compound. A c... Salmonella that already have a single mutation,
for example, a strain that cannot produce histidine , an amino acid that is essential
for the bacterium to grow if not provided externally w...
Anabolism
...ses involve "dismantling" of structural proteins
for recycling
for other purposes. Catabolic processes occur during ...tein in order to use amino acids as substrates
for gluconeogenesis (much like burning furniture in ...
Amino acid
...thesis ). These modifications are often essential
for the function of the protein. At least two amino a... that they use to produce methane . It is coded
for similarly to selenocysteine but with the codon UAG... hormone ethylene .
In addition to amino acids
for protein synthesis, there are other biologically im...
Anatomy
... view, however, human anatomy is a scientific and fascinating study, having
for its object the discovery of the causes which have brought about the exist...an anatomy
Organ (anatomy)
Superficial anatomy
Zootomical terms
for location
External links
Free online anatomy atlas
The NPAC V...
Animal
...nd so these groups have been restricted somewhat.
for instance, microscopic protozoa were originally c... metazoans, or eumetazoans when the former is used
for animals in general.
All animals have eukaryotic...form a monophyletic group called the Bilateria .
for the most part, they are bilaterally symmetric, and...
Anaphase
...(M-phase) activity by cleaving and inactivating the M-phase cyclin required
for the function of M-phase cyclin dependent kinases (M-Cdks). It also cleave...biting separase . Separase then cleaves cohesin , the protein responsible
for holding sister chromatids together. They immediately separate, marking the ...
Andrew Huxley
... biophysicist , who won the 1963 Nobel Prize in Physiology or Medicine
for his work with Alan Lloyd Hodgkin on the basis of nerve " action potential...d Huxley shared the prize that year with John Carew Eccles , who was cited
for research on synapses . Hodgkin and Huxley's findings led the pair to hypot...
Antibiotic
...ey are not enzymes .
Unlike previous treatments
for infections, which included poisons such as strych...n effective, with intravenous antibiotics reserved
for more serious cases. Antibiotics may sometimes be a...within a few years, and his research was forgotten
for a generation, until an accident intervened. Alexa...
Antibiotic resistance
...the use of antibiotics as livestock food additives
for growth promotion.
Resistant pathogens
Sta... "quite common" in hospitals. MRSA was responsible
for 37% of fatal cases of blood poisoning in the UK in...e the full course of treatment; do not hoard pills
for later use or share leftover antibiotics.
Vac...
Antibody
...riable domains bind the antigens they are specific
for and that elicited their production.
The abilit...ected (variable (V), diversity (D) and joining (J)
for heavy chains, and only V and J
for light chains) to form countless combinations. The...
Antigen
...mpatibility molecules to T helper cells (CD4 + ). Those that are specific
for them, get activated, so they start to secrete cytokines . The cytokines th...infected cell. In order to keep the cytotoxic cells from killing cells just
for presenting normal proteins, they run through a test cycle (negative control...
Anton van Leeuwenhoek
...om Delft , in the Netherlands . He is best known
for his contribution to improvement of the microscope...cope was used and improved by Christiaan Huygens
for his own investigations into microscopy. He was int...e sold. From there, he grew an insatiable interest
for the field. He spent his nights studying everything...
Antigenic shift
...mals and birds, giving influenza A the opportunity
for a major reorganization of surface antigens. Influe...nidase surface proteins , so they will be called,
for example, H3N2
for type-3 hemagglutinin and type-2 neuraminidase.
I...
Apoptosis
...onfers advantages during an organism's life cycle.
for example, the differentiation of human fingers ...s
2.1 Morphology
2.2 Biochemical signals
for safe disposal
2.3 Intrinsic and extrinsic induc... Cell damage or infection
Apoptosis can occur,
for instance, when a cell is damaged beyond repair, or...
Arabidopsis
...ies, Thale Cress ( Arabidopsis thaliana ), are one of the model organisms
for studying plant sciences, including genetics and plant development. Similarl...c effect in these organs, specimens treated with mutagens and then selected
for the absence of gravitropic action have shown both negative phototropic resp...
Archaea
...t are extremely similar to those of eukaryotes .
for instance, archaean translation uses eukaryotic ini... . Two other groups have been tentatively created
for certain environmental samples and the peculiar spe...h became the nucleus and cytoplasm, which accounts
for various genetic similarities but runs into difficu...
Arbovirus
... An Arbovirus (short
for Arthropod borne virus ) is a virus that is primarily transmitted by arthropods, such as ticks and mosquitoes . The term Arbovirus is not part of...
Artificial life
...ata (CA).
Artificial life is a meeting point
for people from many other more traditional fields suc...Von Neumann felt he needed the complexity in order
for it to function not just as a self-replicating "mac...ng fresh water, harvesting minerals from seawater)
for an investment that would be relatively small compa...
Reproduction
...tion is the creation of one thing as a copy of, product of, or replacement
for a similar thing, e.g. photocopying and the making of replicas .
It is ...tself without the combination of genetic material with another individual.
for example, the Hydra ( invertebrates of the order Hydroidea ) and yeas...