Dorothy Moyle Needham

THE CHEMICAL CHANGES DURING THE METAMORPHOSIS OF INSECTS

The alterations in gaseous exchange and in carbohydrate and fat content of the organism during metamorphosis are described. The nitrogen metabolism of this period is considered, the various fractions, protein nitrogen, basic nitrogen, water‐soluble nitrogen, chitin nitrogen, uric acid nitrogen, etc., being followed as far as possible. The formation of the silk is considered, and the differences in metabolism between insects forming large and those forming insignificant cocoons.

Proteins of the Contractile Mechanism of Mammalian Smooth Muscle and their Possible Location in the Cell [and Discussion]

Dorothy M. Needham speaking. Since the pioneer work of Csapo and his colleagues, beginning about fifteen years ago, it has been realized that from uterine smooth muscle can be extracted a protein closely resembling skeletal-muscle actomyosin in its viscous behaviour, sedimentation rate and electrophoretic mobility. (See, for example, Csapo 1948, 1949, 1950, 1959; Csapo, Erdos, Naeslund & Snellman 1950; Naeslund & Snellman 1951). Later work, in which the properties of purified preparations of myosin, actin and actomyosin have been studied, bears out these earlier conclusions. Thus, for example, we have shown (Needham & Williams 1963b) that skeletal-muscle myosin will react normally with uterus actin to give the highly viscous actomyosin; and similarly uterus myosin with skeletal-muscle actin. In both types of experiment the results indicated that the two proteins associated together in about the same proportions as when both are derived from skeletal muscle. Uterus actomyosin may be fragmented by carefully controlled trypsin treatment giving light and heavy meromyosins which, so far as they have been studied, show similar properties to the meromyosins from skeletal-muscle actomyosin (Needham & Williams 1959; Cohen, Lowey & Kucera 1961). Smooth muscle, however, does contain very strikingly less actomyosin than striated muscle, only 6 to 10 mg/g wet wt as compared with about 70 mg/g wet wt in skeletal muscle (Needham & Williams 1963 a).

The phosphorus distribution in resting fly muscle

REPRESENTATIVE members of nearly all the invertebrate phyla have now been examined for their phosphagen content [Eggleton and Eggleton, 1928; Meyerhof, 1928; Needham, Needham, Baldwin and Yudkin, 1932]. It has been established that creatinephosphoric acid is characteristic of the Vertebrata, while argininephosphoric acid is restricted to the Invertebrata. The two compounds have only been found to co-exist in the Echinoids and in the Enteropneusts. This is of especial interest, since the latter (Hemichordates) form a morphological link between the vertebrate and the echinoderm phyla. Another protochordate group, the Ascidians (Urochordates), have recently been examined by Kreps [1933], who finds creatinephosphoric acid and no argininephosphoric acid; they thus resemble Amphioxus (Cephalochordates). It must be remembered that only in the case of one species (the crayfish, Astacus fluviatilis) has arginine phosphoric acid actually been prepared from invertebrate muscle and analysed [Meyerhof and Lohmann, 1928]. In most cases the evidence for its presence consists in the demonstration of a phosphorus compound, stable in strong acid in presence of molybdate, but hydrolysing in 18 hours at 280 C. in N/20 acid in absence of molybdate. In the cases of Peden, Holothuria and Sipunculus, Meyerhof has supported this evidence by showing that the base of the phosphagen (after hydrolysis) is attacked by arginase with production of urea. It is thus evident that much more work is needed on invertebrate phosphagen. Baldwin [1933] has brought forward evidence suggesting that the cephalopod phosphagen has different properties from argininephosphoric acid, and Arnold and Luck [1933]

BIOCHEMISTRY OF MUSCLE

Publisher Summary This chapter describes the biochemistry of muscles. The energy used by muscle in the performance of work and maintenance of tension is ultimately derived from chemical reactions going on within it. There are different types of skeletal muscles, which are broadly divided into white and red types. The white muscles contract rapidly as compared to the red ones. Red muscle is characterized by its dependence on oxidative metabolism. The chapter discusses the interaction of adenosine triphosphate (ATP) and actomyosin in solutions and gels and also as a basis of muscle contraction. The addition of ATP to an actomyosin solution leads to the dissociation of the two proteins, while removal of the ATP is followed by recombination.

Women in Cambridge Biochemistry

When I look back over my life in science, I recognise how fortunate I was in the intellectual possibilities that opened out before me. Although she had had no university training, one of my aunts, Miss Agnes Daves, established a very successful school (Claremont College, Stockport) of which she was headmistress. I went to this school, and we had very good teaching which included some science, mainly botany. My aunt took a great interest in my future and decided that I could benefit from a university education. She arranged for me to take the entrance examination at Girton College, Cambridge, and actually went with me on my first visit. I duly became a student and lived there from 1915 to 1919.