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.
Take the beef out of the oven when its internal temperature reaches 145 degrees F. A temperature of 155 degrees F signifies a well-done roast for most cuts of beef. Drape a piece of aluminum foil loosely over the roast and allow it to sit out for about half an hour.ooking a beef roast well-done makes the meat less tender and juicy, and considerably more chewy, than beef cooked to a lower temperature. For this reason, it's important to pick the best beef cuts for roasting.