While your body is awake, molecules of adenosine build up and bind to adenosine receptors in your brain. This process slows brain activity and eventually causes tiredness. When you sleep, the concentration of adenosine decreases, allowing you to wake feeling well rested.
Caffeine molecules have a very similar structure to that of adenosine. When you consume coffee, the caffeine enters your blood stream and reaches your brain. Here, it attaches to adenosine receptors, replacing the adenosine. This prevents your body from feeling tired.
However, as your body adapts to the caffeine, it begins producing more receptors to bind with the adenosine. Overtime, the same amount of coffee will not combat tiredness, as adenosine can still bind to the vacant receptors. Now your body requires more caffeine to occupy all of the receptors.
Additionally, caffeine sparks the production of adrenaline, which causes your airways to open, heart to beat faster, and muscles to tighten. This of course makes you feel even more awake and energetic.
Furthermore, caffeine increases the level of dopamine, a neurotransmitter that activates pleasure centers in the brain, making you feel good.
However, these benefits do not last forever. The half-life of caffeine in the body is about six hours, which means it takes six hours for half of the caffeine in your body to decompose. For example, six hours after drinking a cup of coffee with 150 milligrams of caffeine, only 75 milligrams remain in your system. Six hours after that, only 37.5 milligrams are left. Without caffeine, receptors are free to bind with adenosine, causing fatigue. This explains the caffeine high and crash, and why many people rely on coffee to keep them going throughout the day.
Coffee pairs wonderfully with chocolate, another food high in caffeine. Mini mocha sponges feature light coffee sponge cakes topped with a creamy, rich chocolate buttercream frosting.
The sponges start with a simple batter flavored with coffee.
Bake the cakes until they are golden, but still a little sticky on top. This will keep them light and moist, preventing a tough, dry texture.
Extra espresso goes into the frosting to compliment the chocolate.
Once the cakes cool, top with the buttercream for adorable pastries.
Mini Mocha Sponges
3 ½ cups flour
2 tsp baking powder
1 tsp salt
1 tsp cinnamon
2 cups sugar
½ cup oil
1 cup milk
1 cup coffee
2 tsp vanilla
1 ½ cups butter
2 cups semisweet chocolate
2 tsp vanilla
2 tsp espresso powder
1 tsp cinnamon
¼ cup flour
Preheat the oven to 350° F. Place small cupcake holders in a mini muffin tin.
Sift the flour and baking powder. In a separate bowl combine the rest of the cake ingredients and mix. Slowly add the flour mixture to the wet ingredients.
Pour the batter into the tin and bake for 20 minutes or until a toothpick comes out clean. The tops of the cakes should be golden but moist. Let cool.
In a clean bowl, cream the butter. Microwave the chocolate in 30 second intervals to prevent burning. When it is smooth, let cool and then add to butter. Mix in the rest of the ingredients. Cover the frosting and let chill for 10 to 20 minutes to allow for easy piping.
Pipe the buttercream onto the cakes and refrigerate until ready to serve.
Makes 85 mini sponges.
Thanks to these sites for the information on coffee.