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Programme examines the basic approach to enzyme kinetics using carrier mediated transport.
Metadata describing this Open University video programme
Module code and title: S321, Physiology of cells and organisms
Item code: S321; 04
First transmission date: 24-03-1974
Published: 1974
Rights Statement:
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Duration: 00:23:40
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Producer: Jim Stevenson
Contributors: Vic Daniels; Paul Voorheis
Publisher: BBC Open University
Keyword(s): Amino acids; Carrier mediated transport; Enzyme kinetics; Maximal velocity; Michaelis constant; Model
Footage description: Vic Daniels introduces the programme which will discuss the basic approach to enzyme kinetics using carrier mediated transport. Daniels uses a model of an enzyme molecule to demonstrate its action as a carrier for a substrate. He compares this process with an enzyme reaction where a product is formed. Daniels discusses rate of reaction for the enzyme-substrate carrier process. He uses the model to aid. Animated diagram of a cross-section of a membrane shows the carrier reaction. The diagram shows the relationship between amount of substrate and velocity of the carrier reaction. A graph shows the relationship between amount of substrate and reaction velocity. Daniels explains how the derivation of the kinetic constants can be simplified. A reciprocal curve form is plotted on the graph and a straight line curve results. Daniels uses the enzyme model again to explain what happens when a reaction inhibitor is introduced. He discusses "competivive inhibition" first. This reaction is plotted on a graph. Daniels explains "non-competitive reactions". He continues to use the enzyme model to aid his commentary. This reaction is also shown on the graph. Daniels sums up his discussion of competitive and non-competitive reactions in the enzyme carrier process. Daniels introduces Paul Voorheis. Paul Voorheis discusses his work: on the transport kinetics of trypanosomes. Shots of trypanosomes under magnification (they are the cause of African Sleeping Sickness) Voorheis discusses his choice of trypanosomes for amino acid transport experiments. Voorheis demonstrates the purification process which obtains samples of trypanosomes from rat blood. The blood is centrifuged and then further separated by column chromatography Both processes are explained and chromatography is demonstrated. Voorheis adds the isolated trypanosomes to a solution of radio-active amino acid. Transport rate is measured in a scintillation counter. Voorheis explains the experiment each step of the way. The count is displayed on the instrument. Voorheis uses several graphs to plot the curves for the effect of substrate concentration on uptake of amino acid. Voorheis explains the effect of introducing an inhibitor to two carriers and shows a graph which plots the results. He explains why it is difficult to explain the curves in terms of their kinetic constants. Voorheis explains how this problem is overcome by using a computer. Shots of a chart showing computer generated data of the effect of inhibitors on kinetic constants. Voorheis sums up. He describes future experiments which may be done to determine why trypanosomes have two carriers for the same amino acid.
Master spool number: 6HT/71334
Production number: 00525_1121
Videofinder number: 1821
Available to public: no