4.1 Chemical Energy and ATP

One function of digestion is to

break down food into smaller molecules that can be used to make ATP

Chemosynthetic organisms don't need ATP for energy.

False

Adding a phosphate group to ADP to make ATP is a simple process.

False, a large, complex group of proteins is needed to do it. In fact, if just one of these proteins is faulty, ATP is not produced.

Carbohydrates provide the most amount of ATP

False, lipids store the most energy. In fact, fats store about 80% of the energy in your body. And, when fats are broken down, they yield the most ATP.

Foods that you eat contain ATP that your cells can use.

False, the food must be digested first.

. Your energy comes from food directly

False, your energy does come from food, but not directly.

ATP has ____ phosphate groups, but the bond holding the _____ phosphate group is unstable and is very easily broken.

three, third

ADP (adenosine diphosphate)

When the phosphate is removed, energy is released and ATP becomes ___

ADP is ____

a lower-energy molecule that can be converted into ATP by the addition of a phosphate group.

A typical triglyceride can be broken down to make about ___ molecules of ATP.

146

ATP (adenosine triphosphate)

A molecule that transfers energy from the breakdown of food molecules to cell processes.

Chemosynthesis

A process by which some organisms use chemical energy to make energy-storing carbon- based molecules.

ATP carries chemical energy that cells can use. Cells use ATP for functions such as building molecules and moving materials by active transport.​

True

All cells, including plant cells, use ATP for energy

True

Carbohydrates and lipids are the most important energy sources in foods you eat. However, this energy is only usable after these molecules are broken down by a series of chemical reactions.

True

The energy carried by ATP is released when a phosphate group is removed from the molecule.

True

The number of ATP molecules produced depends on the type of molecule that is broken down—carbohydrate, lipid, or protein.

True

The processes that make their ATP are very similar to those in other organisms. Like plants, chemosynthetic organisms make their own food, but the raw materials differ.

True

The removal of the third phosphate group usually involves a reaction that releases energy.​

True

Carbohydrates are not stored in large amounts in your body, but they are the molecules most commonly broken down to make ATP. The breakdown of the simple sugar glucose yields about __ molecules of ATP

True, 36

Most, but not all, organisms rely directly or indirectly on sunlight and photo- synthesis as their source of chemical energy.

True, in places that never get sunlight there are areas with living things. Some organisms live in very hot water near cracks in the ocean floor called hydrothermal vents. These vents release chemical compounds, such as sulfides, that can serve as an energy source.

Proteins store about the same amount of energy as carbohydrates, but they are less likely to be broken down to make ATP

True, the amino acids that cells can break down to make ATP are needed to build new proteins more than they are needed for energy.​

Different foods provide different amounts of ATP

True, the number of ATP molecules that are made from the breakdown of food is related to the number of calories in food, but not directly.

Plant cells also need ATP, but plants do not eat food the way animals do. Plants make their own food.

True, through the process of photosynthesis, plants absorb energy from sunlight and make sugars. Plant cells break down these sugars to produce ATP, just as animal cells do