enzyme-catalyzed reactions were dev

enzyme-catalyzed reactions were developed for more complex cases than that of Equation 2 [22, 27, 115]. However, Equation
4 still fits all Michaelis-Menten type reactions, where steady-state concepts are valid. The numerical definitions of
V
max and
K
m
change as the complexity of the reaction changes. In 1965, Monod et al. [80] and Koshland et al. [66] developed equations for
allosteric-behaving enzymes. Other workers [44] developed equations for pre-steady-state treatment of enzyme-catalyzed
reactions.
7.1.4.4 Enzyme Purification
Purification of enzymes began only after 1920. Before 1920, it was generally thought that enzymes were proteins. However,
during the period of 1922–1928, Willstätter and his colleagues purified horseradish peroxidase to the point where it had
appreciable activity even when no protein could be detected by existing methods. Therefore, they concluded, incorrectly, that
enzymes could not be proteins. In 1926, Sumner [98], at Cornell University, crystallized urease from jack beans and showed it
to be a protein. This led to much debate between Willstätter, a noted German chemist, and Summer, with many European
biochemists and chemists siding with Willstätter. Sumner was later awarded the Noble prize for crystallization of the first enzyme
and for showing that enzymes are proteins. Beginning in the 1930s, and continuing to the present, much work has been devoted
to enzyme purification using techniques such as chromatography (ion exchange, gel filtration, chromatofocusing, affinity,
hydrophobic), several types of electrophoresis [regular polyacrylamide gel electrophoresis (PAGE), SDS-PAGE, isoelectric
focusing], and techniques based on solubility and stability differences. Now nearly 3000 enzymes have been purified. All are
proteins.
7.1.4.5 Enzyme Structure
The first primary sequence of a protein, insulin (of 6000 MW), was determined by Sanger and co-workers in 1955 [90] after
almost 10 years of methods development and application. In 1960 [49, 95], the primary sequence of the first enzyme,
ribonuclease (13,683 MW), was determined. Many primary sequences of enzymes are now known, many via gene sequencing.
The secondary and tertiary structures of ribonuclease were determined in 1967 [58]. Now several hundred secondary and
tertiary structures of enzymes are known, including structures in solutions, by nuclear magnetic resonance (NMR). The first
enzyme, ribonuclease, was completely synthesized chemically from amino acids in 1969 by two groups. Now, wild-type and
mutant enzymes can be synthesized almost overnight by the PCR (polymerase chain reaction) method, once the gene has been
isolated. Those of us who have observed advances in protein and enzyme chemistry since the 1940s are astounded and awed
by the remarkable ease and speed at which enzyme sequences and structures can now be determined.
7.1.5 Literature on Enzymology
Perhaps no other single topic has received so much attention from researchers as enzymes. Papers on enzymes can be found in
almost any journal in the physical, chemical, or biological sciences, since they are of interest to chemists, physicists,
mathematicians, chemical engineers, and the life scientists, including food scientists and nutritionists. The bibliography at the end
of this chapter includes selected journals, books, and monographs on enzymes. Obviously, no scientist can keep up completely
in this field. Food scientists should, by all means, be familiar with current progress in fundamental aspects of enzymes, as well as
with applications.

Hasil (Bahasa Indonesia) 1:

reaksi yang dikatalisasi enzim dikembangkan untuk kasus yang lebih kompleks daripada persamaan 2 [22, 27, 115]. Namun, persamaan4 masih cocok semua Michaelis-Menten tipe reaksi, di mana konsep-konsep mapan berlaku. Definisi numerik dariVMax danKmperubahan sebagai kompleksitas perubahan reaksi. Pada tahun 1965, Monod et al. [80] dan Koshland et al. [66] persamaan dikembangkan untukenzim alosterik berperilaku. Lain persamaan pekerja [44] dikembangkan untuk pengobatan pra-steady-negara dikatalisasi enzimreaksi.7.1.4.4 pemurnian enzimPemurnian enzim mulai hanya setelah 1920. Sebelum 1920, ia umumnya berpikir bahwa enzim adalah protein. Namun,selama periode tahun 1922-1928, Martin Willstätter dan rekan-rekannya dimurnikan lobak peroksidase ke titik di mana itucukup besar aktivitas bahkan ketika protein tidak dapat dideteksi dengan metode yang ada. Oleh karena itu, mereka menyimpulkan, keliru, bahwaenzim tidak bisa protein. Pada tahun 1926, Sumner [98], di Universitas Cornell, mengkristal urease dari jack kacang dan menunjukkanmenjadi protein. Hal ini menyebabkan banyak perdebatan antara Martin Willstätter, seorang kimiawan Jerman yang terkenal dan musim panas, dengan banyak Eropaahli biokimia dan kimiawan berpihak Martin Willstätter. Sumner kemudian dianugerahi Hadiah mulia untuk kristalisasi enzim pertamadan untuk menunjukkan bahwa enzim protein. Awal tahun 1930-an, dan terus berlanjut hingga sekarang, banyak kerja telah setiauntuk pemurnian enzim yang menggunakan teknik seperti kromatografi (pertukaran ion, filtrasi gel, chromatofocusing, afinitas,hidrofobik), beberapa jenis Elektroforesis [reguler polyacrylamide Elektroforesis (halaman), SDS-halaman, isoelektrikfokus], dan teknik-teknik yang didasarkan pada perbedaan kelarutan dan stabilitas. Sekarang hampir 3000 enzim telah dimurnikan. Semuaprotein.7.1.4.5 struktur enzimUrutan utama pertama protein, insulin (dari 6000 MW), ditentukan oleh Sanger dan rekan kerja tahun 1955 [90] setelahhampir 10 tahun pengembangan metode dan aplikasi. Pada tahun 1960 [49, 95], urutan utama enzim pertama,katalisis (13,683 MW), ditentukan. Urutan utama banyak enzim yang sekarang diketahui, banyak melalui sequencing gen.Struktur sekunder dan tersier katalisis bertekad pada tahun 1967 [58]. Sekarang beberapa ratus menengah danstruktur tersier enzim dikenal, termasuk struktur dalam solusi, dengan resonansi magnetik nuklir (NMR). Yang pertamaenzim, katalisis, benar-benar disintesis kimia dari asam amino pada tahun 1969 oleh dua kelompok. Sekarang, wild-jenis danmutan enzim dapat disintesis hampir semalam dengan metode PCR (PCR), setelah gen telahterisolasi. Mereka yang telah mengamati kemajuan dalam protein dan enzim kimia sejak 1940-an terkejut dan terpesonadengan kemudahan luar biasa dan kecepatan di mana enzim urutan dan struktur dapat sekarang ditentukan.7.1.5 literatur tentang EnzymologyMungkin tidak ada pembahasan lain telah menerima begitu banyak perhatian dari para peneliti sebagai enzim. Karya-karya enzim dapat ditemukan dihampir semua jurnal dalam ilmu fisik, kimia, atau biologi, karena mereka menarik bagi kimiawan, fisikawan,matematikawan, insinyur kimia, dan para ilmuwan hidup, termasuk makanan ilmuwan dan ahli gizi. Bibliografi pada akhirBab ini mencakup dipilih jurnal, buku, dan monograf pada enzim. Jelas, ilmuwan tidak dapat menjaga sepenuhnyadalam bidang ini. Ilmuwan pangan, dengan segala cara, harus akrab dengan kemajuan yang saat ini dalam aspek-aspek mendasar enzim, juga sebagaidengan aplikasi.