Thylakoid Definition. A thylakoid is a sheet-like membrane-bound structure that is the site of the light-dependent photosynthesis reactions in chloroplasts and cyanobacteria. It is the site that contains the chlorophyll used to absorb light and use it for biochemical reactions.
Turn the oven down to 200ÂºF and cook for about 1 hour per pound. Check your meat with a thermometer after 2.5 hours for a 2.5 pound roast. Follow these guidelines for doneness when checking temperature 1  : 130ÂºF Rare.
The oven should be preheated to 500 degrees Fahrenheit. Once the steak has been seared, place it on a baking dish and into the oven for about two to three minutes for medium, three to four additional minutes for well done. Remove the steak from the oven and let it sit on a platter covered with foil for about 10 minutes to relax.