2017. október 29., vasárnap

Megvan, hogy az orvosok és az elméleti tudósok miért utasítják el a projektjavaslatomat ... Mert ez mérnöki feladat !

... These are only some of the more straightforward examples. Release of genetically engineered organisms into the environment carries with it a level of risk that is sometimes difficult to evaluate. Human gene therapy (Box 28-2), with all of its promise, doubtless will present society with ethical dilemmas not yet anticipated. Issues of this kind must in the end foster a closer and more productive collaboration between science and the society it serves, as well as higher levels of scientific literacy in the general public, as we move toward the twenty-first century.

Lehninger-Nelson-Cox: Principles of Biochemistry, 1010.o.

2017. október 6., péntek

Nem azért mondom, de ez elképesztő: az élet-technológia !

Ez nem csak úgy magától pöndörödik, ezt pöndöríteni kell ! ... Ez komplett gyártási folyamat:

In every cell, DNA supercoiling is a precisely regulated process that influences many aspects of DNA metabolism. Not surprisingly, there are enzymes in every cell whose sole purpose is to underwind and/or relax DNA. The enzymes that increase or decrease the extent of DNA underwinding are called topoisomerases, and the property of DNA they affect is the linking number. These enzymes play an especially important role in processes such as replication and DNA packaging. There are two classes of topoisomerases. Type 1 topoisomerases act by transiently breaking one of the two DNA strands, rotating one of the ends about the unbroken strand, and rejoining the broken ends; they change Lk in increments of 1. Type 2 topoisomerases break both DNA strands and change Lk in increments of 2.

Lehninger-Nelson-Cox: Principles of Biochemistry, 805.o.

2017. október 4., szerda

Az élet-információ drága !

Forming specific bonds and preventing sequence errors in these polymers has an enormous impact on the thermodynamics, chemistry, and enzymology of the synthetic processes. For example, formation of a peptide bond should require an input of only about 21 kJ, and relatively simple enzymes that catalyze comparable reactions are known. To synthesize the correct peptide bond between two specific amino acids at a given point in a protein, however, the cell invests about 125 kJ in chemical energy and makes use of the combined activities of over 200 RNA molecules, enzymes, and specialized proteins. Information is expensive.

Lehninger-Nelson-Cox: Principles of Biochemistry, 790.o.

2017. október 2., hétfő

A "supercoil" ("pödört söndör" ?) ... Hogyan fogjuk ezt az unokáinknak elmagyarázni ?

Figure 23-9 Supercoils. A typical phone cord is a coil. A phone cord twisted as shown is a supercoil. The illustration is especially appropriate, because an examination of the twisting of phone cords helped lead Jerome Vinograd and colleagues to the insight that many properties of small, circular DNAs could be explained by supercoiling. They first detected DNA supercoiling in small, circular viral DNAs in 1965.

Lehninger-Nelson-Cox: Principles of Biochemistry, 799.o.

Szószedet: homeostasis (önbévület*)

homeostasis : The maintenance of a dynamic steady state by regulatory mechanisms that compensate for changes in external circumstances. ___...