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Holt McDougal Biology 1 Cells and Energy Study Guide A Study Guide 4.1: Chemical Energy and ATP

Name ______________________________ Period _____________Date _______________

Study Guide 4.1: Chemical Energy and ATP

KEY CONCEPT:

All cells need chemical energy.

VOCABULARY

MAIN IDEA: The chemical energy used for most cell processes is carried by ATP.

Circle the word or phrase that best completes the statement.

1. All cells use adenosine triphosphate (ATP) for energy. ATP is a molecule / organelle that

transfers energy from the breakdown of ADP / food molecules to cell processes.

2. ATP is a high-energy / low-energy molecule that is converted into

higher-energy / lower-energy ADP when a phosphate group is removed

and energy is released.

3. ADP is converted back into ATP by the addition of a phosphate group /

food molecule.

4. Put the letter of the appropriate statement into each box of the cycle diagram below to show

the relationship between ATP and ADP.

a. High-energy adenosine triphosphate (ATP)

b. Lower-energy adenosine diphosphate (ADP)

c. Energy added from breakdown of carbon-based molecules, phosphate added

d. Phosphate removed, energy released

ATP ADP chemosynthesis

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Holt McDougal Biology 2 Cells and Energy Study Guide A Study Guide 4.1: Chemical Energy and ATP

MAIN IDEA: Organisms break down carbon-based molecules to produce ATP.

Put the letter for each of the following six statements into the appropriate list to identify the roles of different types of molecules when they are broken down to make ATP.

a. molecules least likely to be broken down

b. molecules most commonly broken down

c. molecules that store most of the energy in a person’s body

d. triglyceride yields about 146 ATP

e. glucose yields about 36 ATP

f. store about the same amount of energy as carbohydrates

MAIN IDEA: A few types of organisms do not need sunlight and photosynthesis as a source

of energy.

Circle the word or phrase that best completes the statement.

8. Chemosynthesis is a process by which some organisms use chemical energy / light

energy instead of chemical energy / light energy to make energy-storing carbon-based

molecules.

Vocabulary Check: Fill in each blank with the word or phrase that best completes the sentence.

9. The prefix tri- means “three,” and the prefix di- means “two.” Therefore, adenosine

triphosphate (ATP) has ___________ phosphate groups, and adenosine diphosphate (ADP)

has __________________ phosphate groups.

10. The prefix chemo- means “chemical,” and synthesis comes from a Greek word that means

“to put together.” Therefore, chemosynthesis means “to put together with chemicals.” In

chemosynthesis, ______________ energy is used to produce carbon-based ____________

that store energy.

Type of Molecule Role in ATP Production

5. Carbohydrates

4 calories per mg (4 Calories per gram)

6. Lipids

=

9 calories per mg (9 Calories per gram)

7. Proteins

9 calories 4 calories per mg (4 Calories per gram)

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Holt McDougal Biology 3 Cells and Energy Study Guide A Study Guide 4.1: Chemical Energy and ATP

REINFORCEMENT 4.1: Chemical Energy and ATP

KEY CONCEPT All cells need chemical energy.

All cells need chemical energy for their functions. The energy that your cells need

comes indirectly from the food you eat. The chemical energy used by all cells is carried by a

molecule called adenosine triphosphate, or ATP. ATP is a molecule that transfers energy from

the breakdown of molecules in food to cell processes.

A molecule of ATP has three phosphate groups. The energy carried by ATP is

released when the third phosphate group is removed from the molecule by a chemical reaction.

When the phosphate group is removed and energy is released, ATP is converted into a molecule

called adenosine diphosphate, or ADP. ADP is a lower-energy molecule that can be changed

back into ATP by the addition of another phosphate group.

Different types of carbon-based molecules (carbohydrates, lipids, and proteins) can

be broken down to produce ATP. The breakdown of the different molecules produces different

amounts of ATP. Carbohydrates, especially the simple sugar glucose, are most commonly

broken down to make ATP. The breakdown of a lipid produces many more ATP molecules than

does the breakdown of a sugar. Proteins are the molecules least likely to be broken down, but

they store about the same amount of energy as carbohydrates.

Many organisms must eat other organisms to get the carbon-based molecules they

need to make ATP. Some organisms, such as plants, use a process called photosynthesis to make

their own food molecules. Other organisms that survive without light can make their own food

molecules through a process called chemosynthesis.

1. What is the function of ATP?

______________________________________________________________

______________________________________________________________

2. What is ADP?

______________________________________________________________

______________________________________________________________

3. Which types of carbon-based molecules can be broken down to make ATP?

______________________________________________________________

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Holt McDougal Biology 4 Cells and Energy Study Guide A Study Guide 4.1: Chemical Energy and ATP

Section Quiz 4.1: Chemical Energy and ATP

Choose the letter of the best answer.

______ 1. Which of the following statements is true for all cells?

a. They use solar energy.

b. They use photosynthesis.

c. They use chemical energy.

d. They use chemosynthesis.

______ 2. Which phrase best describes the function of the ATP molecule?

a. stores energy

b. carries energy

c. absorbs energy

d. converts energy

______ 3. Where does the chemical energy to produce ATP come from?

a. the conversion of ATP to ADP

b. the use of chemicals from the environment to build sugars

c. the addition of a phosphate group to ATP

d. the breakdown of carbon-based molecules into smaller molecules

______ 4. Energy is released from an ATP molecule for cellular processes when it

a. has a phosphate group removed.

b. stores an extra phosphate group.

c. converts a phosphate group to ADP.

d. produces a sugar molecule.

______ 5. Which of the following is the source of energy used in chemosynthesis?

a. sunlight

b. heat from hydrothermal vents

c. chemical compounds

d. amino acids