Each bean contains 0.8 - 2.5 % caffeine. For your information in an average cup of coffee you have 75mg caffeine. One cup of coffee contains around 25 coffee beans, and you are not getting the full coffee bean in coffee, so the caffeine can add up if you eat a lot.
The reason why temperature effects muscles is because of the numerous atoms in the body that react to temperature. When the air, or body temperature is colder the atoms tend to stay closer together, causing less movement...when it is hot, the atoms (molecules) move around more, causing more range of motion. It also allows blood to flow more easily when it is warm than cold.
The rate of enzyme reactions is affected by temperature. All enzymes have an optimum temperature range in which they work most efficiently. An enzyme is most active at its optimum temperature. A temperature rise beyond this point reduces enzyme activity till it completely stops. This happens because the enzymes structure has changed, (often a loss of the correct folding of the molecule) and it's irreversiable.