Effect of Ascending an Ordinary Flight of Stairs on the Work of the Heart Observations on Normal Individuals and on Patients withCoronary Heart Disease By JAMESA. L. MATHERS,M.D.,HAROLD I. GRIFFEATH,M.D.,ROBERTL.LEVY,M.D., AND JOHNL. NICKERSON,PH.D.he blood pressure cuff andelectrocardiograplhic electrodes remained on the ex-tremities during the exercise to facilitate the speedof making the observations during the recovery period. All obstructions, such as closed doors andotherpersons, wereremoved fromthe path ofthesub-ject being tested.
Restriction enzymes, also known as restriction endonucleases, are enzymes that cut a DNA molecule at a particular place. They are essential tools for recombinant DNA technology. The enzyme scans a DNA molecule, looking for a particular sequence, usually of four to six nucleotides. Once it finds this recognition sequence, it stops and cuts the strands. This is known as enzyme digestion. On double stranded DNA the recognition sequence is on both strands, but runs in opposite directions.
Digestive enzymes are a group of enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption by the body. Digestive enzymes are found in the digestive tracts of animals and in the traps of carnivorous plants, where they aid in the digestion of food, as well as inside cells, especially in their lysosomes, where they function to maintain cellular survival. Digestive enzymes of diverse specificities are found in the saliva secreted by