2018. május 17., csütörtök

Az emberi test = 1014 db sejt "concert"-je !

"Some proteins endow cells and organisms with the ability to contract, to change shape, or to move about. Actin and myosin function in the contractile system of skeletal muscle and also in many nonmuscle cells. Tubulin is the protein from which microtubules are built. Microtubules act in concert with the protein dynein in flagella and cilia (Fig. 6–1d) to propel cells."

... Lehninger-Nelson-Cox: Principles of Biochemistry, 135.o.

2017. december 26., kedd

Szószedet: attraction (vonzás)

The dependence on r2 is such that ionic attractions or repulsions operate over limited distances, in the range of 10 to 40 nm (depending on the electrolyte concentration) when the solvent is water.
 ... Lehninger-Nelson-Cox: Principles of Biochemistry, 84.o.

2017. december 19., kedd

Szószedet: exciting (izgalmas)

... familiarity with them is a prerequisite for understanding more advanced topics covered in this book, as well as the rapidly growing and exciting literature of biochemistry.

Lehninger-Nelson-Cox: Principles of Biochemistry, 109.o.

... Játsszunk biokémiát ! ... :)

2017. december 16., szombat

Szószedet: bioinformatika (language of biochemistry)

We begin in each case by considering the covalent structure of the simple subunits (amino acids, fatty acids, monosaccharides, and nucleotides). These subunits are a major part of the language of biochemistry; familiarity with them is a prerequisite for understanding more advanced topics covered in this book, as well as the rapidly growing and exciting literature of biochemistry.

Lehninger-Nelson-Cox: Principles of Biochemistry, 109.o.

2017. december 9., szombat

Szószedet: egyszerűség (simplicity)

The relevant facts of biochemistry are many; the student approaching this subject for the first time may occasionally feel overwhelmed. Perhaps the most encouraging development in twentieth-century biology is the realization that, for all of the enormous diversity in the biological world, there is a fundamental unity and simplicity to life. The organizing principles, the biochemical unity, and the evolutionary perspective of diversity, provided at the molecular level, will serve as helpful frames of reference for the study of biochemistry.
... http://a-aa.vectrix.hu/bioinfo/abox.php?o=o#1.6

Although living organisms contain a very large number of different proteins and different nucleic acids, a fundamental simplicity underlies their structure (Chapter 1). The simple monomeric subunits from which all proteins and all nucleic acids are constructed are few in number and identical in all living species. 
... http://a-aa.vectrix.hu/bioinfo/abox.php?o=o#.69

2017. november 23., csütörtök

Vannak akik azt mondják, hogy az egysejtűektől a többsejtűekhez evolúciós ugrás kellett - pedig nem: sima átmenet !

At some later stage of evolution, unicellular organisms found it advantageous to cluster together, thereby acquiring greater motility, efficiency, or reproductive success than their free-living single-celled competitors. Further evolution of such clustered organisms led to permanent associations among individual cells and eventually to specialization within the colony – to cellular differentiation.


The advantages of cellular specialization led to the evolution of ever more complex and highly differentiated organisms, in which some cells carried out the sensory functions, others the digestive, photosynthetic, or reproductive functions. Many modern multicellular organisms contain hundreds of different cell types, each specialized for some function that supports the entire organism. Fundamental mechanisms that evolved early have been further refined and embellished through evolution. The simple mechanism responsible for the motion of myosin along actin filaments in slime molds has been conserved and elaborated in vertebrate muscle cells, which are literally filled with actin, myosin, and associated proteins that regulate muscle contraction. The same basic structure and mechanism that underlie the beating motion of cilia in Paramecium and flagella in Chlamydomonas are employed by the highly differentiated vertebrate sperm cell. Figure 2–25 illustrates the range of cellular specializations encountered in multicellular organisms.


Figure 2–26 Three types of junctions between cells.
(a) Tight junctions produce a seal between adjacent cells. (b) Desmosomes, typical of plant cells, weld adjacent cells together and are reinforced by various cytoskeletal elements. (c) Gap junctions allow ions and electric currents to flow between adjacent cells.


Lehninger-Nelson-Cox: Principles of Biochemistry, 49.o.

Az emberi test = 10<sup>14</sup> db sejt "concert"-je !

"Some proteins endow cells and organisms with the ability to contract, to change shape, or to move about. Actin and myosin function...