Powers Unit 4 ADP/ATP

ATP Notes

Unit 3: Cellular Energy

What is ATP? How is it used

in cells? What is the

difference between ATP and
ADP? What are the steps of

the ATP/ADP cycle?

Transformation of Energy

• Cellular processes require

energy – the ability to do
work.

• Thermodynamics is the

study of the flow and
transformation of energy
in the universe.

Autotrophs and Heterotrophs

• Directly or indirectly, nearly all the

energy for life comes from the
Sun.

• Autotrophs make their own food,

either with energy from the sun or
from inorganic substances.

• Heterotrophs ingest other

organisms to obtain energy.

Metabolism

• All of the chemical reactions in a

cell are referred to as the cell’s
metabolism.
○ Catabolic pathways release

energy by breaking down
larger molecules.

○ Anabolic pathways use energy

to build larger molecules.

Cellular Energy Processes

• Photosynthesis – anabolic

pathway in which light energy
from the Sun is converted to
chemical energy for use by the cell

• Cellular respiration – catabolic

pathway in which organic
molecules are broken down to
release energy for use by the cell

Adenosine Triphosphate

• In living things, chemical energy

is stored in biological
molecules.

• Adenosine triphosphate

(ATP) is the most important
biological molecule that
provides chemical energy.

• Energy is stored in the bonds!!!

Adenosine Triphosphate

• Most abundant energy-carrier in cells
• Nucleotide made of an adenine base, a

ribose sugar, and three phosphate groups

• Most of the energy is stored between the

second and third phosphate groups

Adenosine Triphosphate

• Energy is released when the

bond between the second and
third phosphate groups is
broken.

• Transforms into a molecule

called adenosine
diphosphate (ADP) and a free
phosphate group.

Where do we get our energy?

• Carbohydrates are the

molecules most commonly
broken down to make ATP
during cellular respiration.
○ not stored in large amounts
○ up to 36 ATP from one

glucose molecule

Where do we get our energy?

•Fats store the most energy.
○

80 percent of the energy in your
body

○

about 146 ATP from a triglyceride

•Proteins are least likely to be broken
down to make ATP.
○

amino acids not usually needed for
energy

○

about the same amount of energy
as a carbohydrate (36 ATP)

Other Ways to Obtain Energy

● While most energy storing food molecules obtain their

energy from the sun, a few types of organisms do not
need sunlight or photosynthesis as a source of energy.

● Some organisms live in places that never get sunlight.
● In chemosynthesis, chemical energy is used to build

carbon-based molecules.
○ similar to photosynthesis
○ uses chemical energy instead of light energy

ATP Concept Map

●

ATP stands for adenosine triphosphate.

●

The function of ATp is to provide energy for cell function.

●

The molecular structure of ATP includes:
○

1 Nitrogen Base (Adenine)

○

1 Sugar (Ribose)

○

3 Phosphate Groups

●

The definition of ATP is a molecule used directly by cells
for energy and is created after the breakdown of food
molecules.

ATP Concept Map

● Structure of ATP molecule:

ATP Concept Map

●

Examples of ATP usage include:
○

Active Transport (protein pumps, endocytosis,
exocytosis)

○

Muscles, nerves, heart, etc.

○

Making macromolecules (glucose, proteins, etc.)

●

When ATP is used for energy, a phosphate is removed. This
results in ADP (adenosine diphosphate), energy, and the
removed phosphate.

●

ATP is produced during cellular respiration and
photosynthesis.

ATP Concept Map

● Vocabulary:

○ glucose = sugar made in photosynthesis

and used in cellular respiration

○ phosphorylation = do not need to know :)
○ cellular respiration = food energy turns

into chemical energy (ATP)

○ ATP synthase = enzyme used to make ATP

ATP/ADP Cycle