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.

2017. november 4., szombat

Ötlet: a "growth factor" mintájára, amit mi keresünk, azt nevezzük el "aging factor"-nak !

Figure 22-15 (a) Location of the hypothalamus and pituitary gland. (b) Details of the hypothalamus-pituitary system. Signals arriving from connecting neurons stimulate the hypothalamus to secrete hormones destined for the anterior pituitary into a special blood vessel, which carries the hormones directly to a capillary network in the anterior pituitary. In response to each hypothalamic hormone, the anterior pituitary releases its appropriate hormone into the general circulation. Posterior pituitary hormones are made in neurons arising in the hypothalamus, transported in axons to nerve endings in the posterior pituitary, and stored there until released into the blood in response to a neuronal signal.

The hypothalamic hormones pass directly to the nearby pituitary gland through special blood vessels and neurons that connect the two glands (Fig. 22-15b). The pituitary gland has two functionally distinct parts. The anterior pituitary responds to hypothalamic hormones carried in the blood, by producing six tropic hormones or tropins (from the Greek tropos, meaning "turn"), relatively long polypeptides that activate the next rank of endocrine glands (Fig. 22-14). Adrenocorticotropic hormone (ACTH, also called corticotropin; Mr 4,500) stimulates the adrenal cortex; thyroid-stimulating hormone (TSH, also called thyrotropin; Mr 28,000) acts on the thyroid gland; follicle-stimulating hormone (FSH; Mr 34,000) and luteinizing hormone (LH; Mr 20,500) act on the gonads; and growth hormone (GH, also called somatotropin; Mr 21,500) stimulates the liver to produce several growth factors.

Lehninger-Nelson-Cox: Principles of Biochemistry, 752.o.

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.

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 nucleoti...