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.
Season the steak with kosher salt but not pepper, as the pepper may burn while baking. Preheat the oven to 285 degrees Fahrenheit, or 250 degrees Fahrenheit if using an oven fan. Cover a pan with tinfoil to create a dripping tray. Set the steak on a grill rack, place it in the oven and set the drip tray directly beneath. Shut the oven door and set a timer for 25 minutes. Use a thermometer to check the steak's internal temperature, and remove the steak when it is just below the desired level of doneness.