293 research outputs found

    The synthesis of hemoglobin in a cell-free system

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    The microsomal particles (1) have been implicated as the major sites of protein synthesis within the cells of a variety of tissues. The studies of Borsook, Zamecnik, Hultin, and others, with intact animals and various types of whole cell systems (see review by Askonas et al. (2)), as well as electron-microscope studies (3), provided the original evidence for this conclusion. Zamecnik and Keller (4) have, in addition, developed cell-free systems which incorporate C14-labeled amino acids into protein. These include microsomes as well as various soluble enzymes (5). Further studies have partially defined the intermediate stages involved (6). However, it has not yet been possible to equate incorporation of labeled amino acid into protein with actual protein synthesis (see review by Campbell (7))

    What Goes on Here...

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    SOME of the more frequent complaints around the campus concerns courses that are \u27required\u27 and, occasionally, courses we\u27d like to elect but don\u27t, simply because we can\u27t get \u27credit\u27 for them..

    Further Studies in the Technique of Evaluating Biological Background (Abstract)

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    A six-category test of biological background, consisting of terms, names of men, etc., was constructed. Three alternate forms, marked by the same key and of equal difficulty, according to an item analysis, were made. Correlation of odd and even items gave reliability coefficients of + .88 and + .90. Statistical analysis of 500 tests of college and high school students in the state showed significant differences, by analysis of variance, among the following groups: graduate students, juniors and seniors, freshmen and sophomores, and high school students. Norms are given for these groups. No significant differences were found among different comparable student groups throughout the state. An indication of the validity of the test is shown by a correlation of + .53 with the final examination of forty students in one physiology class. The test may be useful in sectioning large classes in biology and estimating aptitude in this area

    Factors concerned in tyrosine metabolism

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    Preliminary Evaluation of a Test for Biological Background

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    A test, composed of 140 items, including names of men and terms associated with biology, was given to 65 undergraduate students with various majors and 25 graduate students in zoology. The undergraduates\u27 records were analyzed to ascertain the effect of giving the test, with and without time limits, to comparable groups. On the basis of data obtained, a revision of the test was made using 100 select items. This revision was given to 18 graduate and 33 undergraduate students. Correlation of odd versus even items for the separate groups yielded reliability coefficients of + .90 after correction for length. A correlation of r, + .53 was obtained between the final examination grades of nineteen persons in one class in biology and the revised test. The results are offered only as preliminary to a more complete study being carried out

    What Goes on Here...

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    SOME of the more frequent complaints around the campus concerns courses that are 'required' and, occasionally, courses we'd like to elect but don't, simply because we can't get 'credit' for them...</p

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