Understanding Energy in Living Organisms: ATP, ADP, and Cellular Processes
Energy
(Physics) The Capacity of a Physical System to Do Work
Needed by all living things.
What are the cells busy using energy for when you are sleeping?
The cells use energy to build new molecules and get rid of wastes.
What would happen if cells didn’t have the ability to get and use energy?
The cells would die.
What are 3 forms of energy?
Light, heat, and electricity.
Chemical Bond
An attractive force that holds together the atoms, ions, or groups of atoms in a molecule or compound.
Where is chemical energy stored?
Chemical bonds.
What happens when you light a candle and the wax burns?
Chemical bonds between hydrogen and carbon atoms are broken and new bonds form between the atoms and oxygen from the air.
What is the result of bonds that form from candle wax burning?
New molecules of carbon dioxide and water.
How much energy do bonds in new molecules store?
Less than before.
What happened to the extra chemical energy from the old chemical bond?
It changes form.
Do living things use chemical energy?
Yes.
What is one of the most important chemicals cells use? Why?
Adenosine Triphosphate (ATP). It is a chemical that is used to store and give off energy.
ATP
A chemical substance that can diffuse to any part of the cell and release energy. This energy is used for a wide range of processes including active transport and protein synthesis.
What is ATP composed of?
Adenine, ribose, and 3 phosphate groups.
Adenine
(Biochemistry) Purine base found in DNA and RNA.
Purine Base
Aromatic bases found in DNA and RNA that are derived from purine. They have a double ring structure and include adenine and guanine.
Purine
Adenine and Guanine.
Ribose
A pentose sugar important as a component of ribonucleic acid.
ADP
(Adenosine Diphosphate) The compound that remains when a phosphate group is removed from ATP, releasing energy.
What is the difference between ADP and ATP?
ADP has 2 phosphate groups and ATP has three phosphate groups.
What does a cell do when it has extra energy?
Store small amounts of it by adding 1 phosphate group to ADP molecules turning it into ATP.
How can cells give off energy stored in ATP?
By breaking the chemical bonds between the second and third phosphate groups.
What can a cell do when it needs to store or release energy?
Add or subtract a phosphate group whenever it needs to store or release energy.
Why is ATP useful to cells?
ATP can easily release and store energy by breaking and re-forming the bonds between its phosphate groups.
What are some uses for ATP?
Used by cells to power active transport, provides the energy needed to move substances in or out of many cells.
What proteins does ATP help?
Proteins in muscles need help from ATP to slide closer together. This motion causes the muscles to flex.
What type of cells also rely on the use of ATP?
Cells that crawl, twist, and swim.
What other events does ATP energy power?
Making proteins and responses to chemical signals outside of the cell.
What does the small amount of ATP allow for?
A few seconds of activity.
Why do most cells store such little amounts of ATP?
Because it is great for giving off a small amount of energy very quickly and it is not good for storing large amounts for a long time.
Which is better for energy storage: sugar glucose or ATP?
Sugar glucose.
How much more energy does a sugar glucose molecule store than ATP?
More than 90 times that of ATP. Making more sense for cells to store energy in the form of glucose.
What can cells use stored glucose for?
To make ATP and ADP as needed.
What do cells have to do once they have used up their supply of ATP?
Find a way to make more of it.
Where do living things get the energy they need to make ATP?
Comes from the chemical compounds called food, which can come from many different sources.
What are heterotrophs?
Living things that get food by eating other living things.
What are ways for heterotrophs to get their food?
Eating other animals or plants, or breaking down the tissue of dead things.
What is a plant that heterotrophs eat?
Grass.
What would a cheetah do for food?
Eat other animals.
What would mushrooms do for food?
Break down the tissue of dead things.
Where does the energy in most molecules first come from?
The sun.
What do plants, algae, and some bacteria do for food?
Use light energy from the sun to make their own food.
What are autotrophs?
Living things that make their own food.
What are some examples of autotrophs?
Plants, algae, and some bacteria.
What does Earth depend on autotrophs for?
To get energy from the sunlight and store it in the molecules that make up food.
What process do autotrophs use to make food?
Photosynthesis.
What is photosynthesis?
Autotrophs use sunlight energy to produce high-energy carbohydrates – sugars and starches – that can be used as food.
ADP
A molecule that can be converted into ATP through the addition of a phosphate; what ATP becomes when it loses a phosphate.