CHAPTER 5 Energy Balance and Metabolism LESSON 4 Metabolic Energ

The human body needs _____to function (stay alive) and to fuel physical activity. This comes from the food we eat: carbohydrates, protein, and fats. Complex organic food molecules such as sugars, fats, and proteins are rich sources of energy for cells.

• calories

• energy

Complex organic food molecules such as sugars, fats, and proteins are rich sources of energy for cells. This is because much of the energy used to form these molecules is stored within the _____bonds that hold them together.

• chemical

• natural

Through a series of chemical reactions in which ______are transferred from one molecule to another, the composition and energy content of both the donor and acceptor molecules are changed. (food energy)

• impulses

• electrons

__________are broken down to glucose and converted into energy (ATP) for immediate use, stored for later use in the form of glycogen, or converted to body fat.

• Proteins

• Carbohydrates

Fats and protein can also be broken down and used to make ____ in more complex metabolic pathways. The body does store a minimal amount of ATP within the muscles, but the majority is metabolized from the foods we eat.

• ATE

• ATP

Food is made up of carbohydrates, fats, and proteins, and these nutrients are broken down into their simplest forms (glucose, fatty acids, and amino acids) during digestion. Once these nutrients are broken down, they are transported through the ____to either be used in a metabolic pathway or stored for later use.

• intestines

• blood

Before the food we consume can be utilized to produce work for exercise, it needs to be transformed into the primary energy source for the body: ATP. Carbohydrates, proteins, and fats need to be _______to create ATP from ADP (adenosine diphosphate) and free phosphate molecules

• metabolized

• transported

The bonds within ATP (between an adenosine molecule and three phosphate molecules) are high-energy bonds, meaning that when one is broken by enzyme reactions, forming ADP and a free phosphate molecule again, it releases useable energy for the body. And the cycle continues to sustain life.

• True

• False

There are _____primary energy systems. Each system is constantly being used, but each plays a different role depending on the availability of energy and the specific demands being placed on them. Each system has unique aspects in how they utilize fuel, replenish ATP, affect metabolism and performance, and gain or lose lean body mass.

• four

• three

The human body can only store approximately 80 to 100 grams of ____, which is only enough energy for a few seconds of high-intensity activity. 

• TEA

• ATP