DNA structure. DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C).The order of these bases is what determines DNA's instructions, or genetic code.NA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). The order of these bases is what determines DNA's instructions, or genetic code.
A beef roast cooked to medium-rare should have an internal temperature of 145Â°F - 150ÂºF after the resting period, and a roast cooked to medium should have an internal temperature of 150Â°F to 160ÂºF. (See the note below). See Beef Doneness for more information on proper cooking temperatures. Cook the roast for about 10 to 15 minutes and then turn it over in the pan. 2  Continue to cook it for another 10 to 15 minutes for every pound. 3  Remove the tenderloin from the oven when the internal temperature of the meat reaches 140Â°F, as indicated on a meat thermometer inserted into the center of the roast.
The method of cooking a roast in a roaster is called braising. A three pound roast would cook aproximately 2 to 2 1/2 hours at 325. The inside temperature should be 140 degree â¦ s for rare, 160 degrees for medium, and 170 degrees for well-done. Use meat theomometer for this.ow long you would cook a 2.2 pound beef roast depends upon how you  like it cooked. For a rare beef roast, cook at 200 degrees  Celsius/390 degrees Fahrenheit for 30 minute â¦ s. For a medium beef  roast, cook for 45 minutes or for well done meat, cook for an hour.