Abiogenesis
... was gradually shown that, at least in the case of
all the higher and readily visible organisms, spontane...d material. It was thus concluded definitely that
all known living organisms arise only from pre-existin...dom natural processes is so unlikely as to be, for
all practical purposes, impossible." [2]
The abo...
Absorption spectrum
...Let us consider white light, which consists of electromagnetic radiation at
all frequencies, passing through a sample of cold gas. For any collection of a...exactly the same frequency as the one absorbed. However, this is emitted in
all directions, not just in the direction in which the electromagnetic radiatio...
Actin
...mportant component in filament production is the Arp2/3 proteins , which serve as sites for nucleation, stimulating the formation of G-actin trimers.
all of these three proteins are regulated by cell signaling mechanism.
Organization
Actin filaments are assembled in two general types of structur...
Active transport
...ype of transport are transmembrane ATPases . A primary ATPase universal to
all cellular life is the sodium-potassium pump , which helps maintain the cel...type of ion can be transported by several enzymes, which need not be active
all the time (constitutively), but may exist to meet specific, intermittent nee...
Albinism
...roven to be associated with albinism (or better: alterations of the genes).
all alterations, however, lead to an alteration of the melanin (pigment/colorin...ed persons are paler in complexion as the rest of the family. The myth that
all persons with albinism have "white hair and red eyes" is not true. Colorless...
Alcohol
...rocarbon chain's dominance.
Because of hydrogen bonding , alcohols tend to have higher boiling points than comparable hydrocarbons and ethers .
all simple alcohols are miscible in organic solvents. This hydrogen bonding means that alcohols can be used as protic solvents .
Alcohols, like water, ...
Albumin
... protein that is produced in the liver and forms a large proportion of
all plasma protein. It is also found in egg white .
The normal range of al... to 5.0 g/dL, and albumin normally constitutes about 60% of plasma protein;
all other proteins present in blood plasma are referred to collectively as glo...
Alexander Fleming
...proceeded over the misgivings of Fleming, who believed that penicillin, for
all its intrinsic worth, would not be able to be produced in sufficient quantit...was long a member of the Chelsea Arts Club , a private club for artists of
all genres, founded in 1891 at the suggestion of the painter James McNeil Wh...
Alfred Russel Wallace
...hed the evidence on both sides, and I remain an utter disbeliever in almost
all that you consider the most sacred truths... I can see much to admire in
all religions... But whether there be a God and whatever be His nature; whether...
Allostery
... change in one subunit is necessarily conferred to
all other subunits. Thus
all subunits must exist in the same conformation. The ...s the T state over the R state. To summarize:
all subunits must exist in the same conformation
eq...
Alga
...t lines of evolutionary development, although they
all appear to have acquired photosynthesis from cyanobacteria .
all algae lack true leaves , roots , flowers , and ... specialized organelles.
Eukaryotic algae
all other algae are eukaryotes and conduct photosynt...
Allele frequency
... cell) and 4% will be homozygous (carrying two copies of the allele). So
all together 36% of diploid individuals would be expected to carry an allele th...ation is said to be in Hardy-Weinberg equilibrium .
The frequencies of
all the alleles of a given gene often are graphed together as an allele freque...
Allostery
... change in one subunit is necessarily conferred to
all other subunits. Thus
all subunits must exist in the same conformation. The ...s the T state over the R state. To summarize:
all subunits must exist in the same conformation
eq...
Alpha helix
...he helix, and corresponds to a translation of 1.5 along the helical axis. The helix is tightly packed; there is almost no free space within the helix.
all amino acid side-chains are arranged at the outside of the helix. The N-H group of amino acid (n) can establish a hydrogen bond with the C=O grou...
Amine
...arbon based group, then it is a primary amine . If two of the hydrogens are replaced by two carbon based groups, then it is a secondary amine . If
all three hydrogens are replaced with three carbon based groups, then it is a tertiary amine . Note: the subscripts on the R groups are simply used to...
Anatomy
...o intricate is the human body that only a small number of professional human anatomists, after years of patient observation, are complete masters of
all its details; most of them specialize on certain parts, such as the brain or viscera, contenting themselves with a good working knowledge of the rest. ...
Animal
... when the former is used for animals in general.
all animals have eukaryotic cells, surrounded by a c...typically feed by drawing in water through pores
all over the body, which is supported by a skeleton ty...d sensory organs. The body is triploblastic, i.e.
all three germ layers are well-developed, and tissues ...
Antibiotic
...her example of selection is Staphylococcus aureus , which could be treated successfully with penicillin in the 1940s and 1950s. At present, nearly
all strains are resistant to penicillin , and many are resistant to nafcillin , leaving only a narrow selection of drugs such as vancomycin useful for ...
Antibiotic resistance
...tal cases of blood poisoning in the UK in 1999, up from 4% in 1991. Half of
all S. aureus infections in the US are resistant to penicillin, methicillin, ...(vancomycin intermediate Staphylococcus aureus ), indicating resistance to
all glycopeptide antibiotics.
A new class of antibiotics, oxazolidinones , b...
Antibody
... chain has a constant region, which is the same by
all immunoglobulins of the same class, and a variable ...globulins of different B cells, but is the same by
all immunoglobulins of the same B cell . Heavy chains...lobulins according to weight. Immunoglobulins are
all in the gamma region. In some disease states ( myel...
Antigenic shift
...al mutation over time of known strains of influenza (or other things, in a more general sense) to evade the immune system.
Antigenic drift occurs in
all types of influenza including influenza A, B and C. Antigenic shift, however, occurs only in influenza A because it infects more than just humans. Aff...
Apoptosis
...cell proliferation, as in cancerous tumors.
Not
all forms of PCD share the characteristic shapes (the morphology ) and sequences of apoptosis, but
all types of PCD are highly regulated processes.
... described in the previous section on development,
all tissue in multicellular animals depends on continu...
Artificial life
...udents of alife did not have an organized field at
all until the 1980s, and often worked in isolation, un...nk, quack, and splash in a pool. It was exhibited
all over Europe until it fell into disrepair. [1]
...the modern age. Peirce was a strong believer that
all of nature's workings were based on logic. The Mic...
Aseptic technique in microbiology
...he closed tube or flask from which, and the closed tube or flask to which the specimen is to be transferred, an innoculating loop , and a fire source,
all on a clean, preferably microbe-free surface with some overhead protection from airborne microbes.
The person would start the fire, and move the e...
ATP synthase
...verall reaction sequence is:
ADP + P i → ATP
ATP synthase in E. coli
These enzymes are of crucial importance in almost
all organisms, because ATP is the common "energy currency" of cells.
In mitochondria , the F O F 1 ATP synthase has a long history of scientific study...
ATPase
...nergy , which the enzyme (in most cases) harnesses to drive other chemical reactions that would not otherwise occur. This process is widely used in
all known forms of life .
Some such enzymes are integral membrane proteins (anchored within biological membranes ), and move solutes across the me...
Avian influenza
...nt is the avian influenza (AI) virus . AI viruses
all belong to the influenza virus A genus of the Ort...m 6 died. The outbreak was limited to Hong Kong .
all chickens in the territory were slaughtered.
In...ed a ban on Malaysian poultry products. A cull of
all poultry has been ordered by the government within ...
B cell
...e B cells mature. It does not (as commonly assumed among immunologists researching mammals) stand for bone marrow , where B cells are produced in
all other vertebrates.
The human body makes hundreds of different types of B cells, and each type has a unique receptor protein on its membrane that wil...
Biology
...ental to the known forms of life .
For example
all forms of life consist of cells , which in turn, a...based on a common carbon -based biochemistry .
all organisms pass on their heredity via the geneti...he central, organizing concepts in biology is that
all life has descended from a common origin through ...
Biodiversity
...:
The variability among living organisms from
all sources, including, inter alia , terrestrial, mar...Diversity. The parties to this convention include
all the countries on Earth with the exception of Ando...odiversity.
Ecological role of biodiversity
all species provide some kind of function to an ecosys...
Barbiturate
... number of fatalities associated with them led to the development of alternative medications, namely benzodiazepines . Today, less than 10 percent of
all sedative/hypnotic prescriptions in the United States are for barbiturates.
Other non-therapeutical use
Barbiturates in high doses are used for...
Bacterium
...es . The term "bacteria" has variously applied to
all prokaryotes or to a major group of them, depending...relationships.
Bacteria are the most abundant of
all organisms. They are ubiquitous in soil , water .... He argued that each of these and the eukaryotes
all evolved separately and in 1990 emphasized this by ...
Bioinformatics
...automatic search for genes and regulatory sequences within a genome. Not
all of the nucleotides within a genome are genes. Within the genome of higher o... measuring protein concentrations with high-throughput mass spectroscopy .
all of these techniques are extremely noise-prone and/or subject to bias in the...
Biochemistry
... Biochemistry is the chemistry of life . Biochemists study the molecules and chemical reactions catalyzed by enzymes that take place in
all living organisms . See the article on molecular biology for a diagram and description of the interrelationship between biochemistry, molecular bi...
Biological tissue
...ents in electron microscopy , immunofluorescence, and frozen sections have
all added to the sum of knowledge in the last couple of decades.
With these to...is.
There are four basic types of tissue in the human body. These compose
all the organs, structures and other contents.
Epithelium - Lines, cov...
Biomechanics
... elastin are considered, to the macroscopic level,
all the way up to the tissue and organ level. Some sim...ming in fish and locomotion in general across
all forms of life, from individual cells to whole or...ces
Applications
Biomechanisms include
all higher-class forms of life. The study of biomecha...
Bone
...of age), whereupon the cartilage ossifies, fusing the two together.
Marrow can be found in most any bone that holds cancellous tissue. In newborns,
all such bones are filled exclusively with red marrow , but as the child ages it is mostly replaced by yellow marrow . In adults, red marrow is mostl...
Biophysics
...ent applies its efforts toward the study of biophysics. This list is hardly
all inclusive. Nor does each subject of study belong exclusively to any particu... mixing between departments.
Biology and molecular biology - Almost
all biophysics efforts are included in some biology department somewhere. To in...
Biopolymer
... A biopolymer is a polymer found in nature.
Starch , proteins and peptides , and DNA and RNA are
all examples of biopolymers, in which the monomer units, respectively, are sugars , amino acids , and nucleic acids . The exact chemical composition an...
BLAST
...g distant relatives of a protein. First, a list of
all closely related proteins is created. Then these pr...ates both query and target nucleotide sequences in
all six possible frames and compares the resulting pro...) : This program translates the target database in
all 6 frames and compares to a protein query sequence....