Category: P

The complex interactions of a polypeptide molecular chain with its environment and itself and other protein entities, which cause the polypeptide molecule to fold up into a highly organized, tightly packed, three-dimensional structure. Proven to occur spontaneously, by Christian B. Anfmsen during the 1960s; for protein molecules outside of living cells. This ability of polypeptide…

The selective, deliberate (re)designing and synthesis of proteins. This is done in order to cause the resultant proteins to carry out desired (new) functions. Protein engineering is accomplished by changing or interchanging individual amino acids in a normal protein. This may be done via chemical synthesis or recombinant DNA technology (i.e., genetic engineering). “Protein engineers”…

A protein that is thought to regulate important activities in the body and brain by inhibiting specific enzymes and interacting with certain body cells. PN-II is formed from a precursor molecule known as beta-amyloid, via metabolic processing of the betaamyloid. Recent research indicates that incorrect metabolic processing of beta-amyloid by the body results in amyloid…

A protein that acts as an inhibitor of protease.  

An antigen whose concentration increases significantly five to ten years prior to the diagnosis of prostate cancer. This means that PSA level measurements could lead to a diagnosis of prostate cancer before symptoms appear. However, a series of tests is required in order to accurately gauge the probability of cancer because PSA levels can also…

Any mechanism for correcting errors in nucleic acid synthesis that involves scrutiny of individual (chemical) units after they have been added to the (molecular) chain. This function is carried out by a 3′ to 5′ exonuclease, among others. Proof-reading dramatically increases the fidelity of the base pairing mechanism.  

Simple organisms that lack a distinct nuclear membrane and other organelles. Many structural systems are different between procaryotes and eucaryotes including the DNA arrangement, composition of membranes, the respiratory chain, the photosynthetic apparatus, ribosome size, the presence or lack of cytoplasmic streaming, the cell wall, flagella, the mode of sexual reproduction, and the presence or…

Defined by America’s Food and Drug Administration (FDA) as “Establishing documented evidence which provides a high degree of assurance that a specific process will consistently produce a (pharmaceutical) product meeting pre-determined specifications and quality characteristics.”  

A short sequence deoxyribonucleic acid (DNA) that is paired with one strand of the template DNA. It is the growing end of the DNA chain and it simply provides a free 3 ‘—OH end at which the enzyme DNA polymerase adds on deoxyribonucleotide units (monomers). Which deoxyribonucleotide is added is dictated by base pairing to…

The sequence of amino acids in a protein chain.