MUSCLe

All animal muscle groups come in
two categorieS
FAST
TWITCH
&
SLOW
TWITCH

FAT

SATURATED
FAT
CHAINS OF EVENLY BONDED MOLECULES STACKED TIGHTLY TOGETHER - MAKING THEM SOLID AT ROOM TEMPERATURE
BEEF HAS A HIGH AMOUNT OF SATURATED FATS.
 
THIS STABILIZES THE PROTEIN SO MUCH THAT IT OXIDIZES SLOWLY AND CAN BE AGED UNDER PROPER CONDITIONS
UNSATURATED
FAT
FRAGILE CHAINS OF UNEVENLY BONDED MOLECULES - MAKING THEM LIQUID AT ROOM TEMPERATURE
CHICKEN AND PORK HAVE A HIGHER AMOUNT OF UNSATURATED FATS. 
THE UNSTABILIZATION MAKES IT PRONE TO FASTER OXIDIZATION AND RANCIDITY