Transcript 4.1 Chemical Energy and ATP

4.1 Chemical Energy and ATP
KEY CONCEPT
All cells need chemical energy.
4.1 Chemical Energy and ATP
• The cells of all organisms—from algae to whales to
people—need chemical energy for all of their
processes.
• Some organisms, such as diatoms and plants, absorb
energy from sunlight. What is a diatom?
– What do they do with it?
- Some of that energy is stored in sugars.
- Cells break down sugars to produce usable chemical energy
for their functions.
Without organisms that make sugars, living things on
Earth could not survive.
4.1 Chemical Energy and ATP
MAIN IDEA: The chemical energy used for most cell
processes is carried by ATP.
You are hungry. You need energy, so you grab what? A
Snickers Bar? A Kit-Kat Bar?
Does this food that contains sugar and other Carbon-based
molecules give you the energy that you need? How does
it provide it to you, exactly?
All carbon-based molecules store chemical energy in their
bonds!
4.1 Chemical Energy and ATP
• Molecules in food store chemical energy in their bonds.
Starch molecule
Glucose molecule
4.1 Chemical Energy and ATP
What is ATP?
Adenosine triphosphate, a molecule that transfers
energy from the breakdown of food molecules to cell
processes.
• ATP carries chemical energy that cells can use.
• Cells use ATP to carry out functions:
– building molecules
– moving materials by active transport.
4.1 Chemical Energy and ATP
How does ATP transfer energy from the breakdown of food
molecules to cell functions?
– ATP has three phosphate groups, but the third has a unstable, weak
bond.
– Energy is released when the third phosphate group is removed.
– ADP is changed into ATP when a phosphate group is added.
phosphate removed
ADP is a lower-energy
molecule that can be
converted into ATP by the
addition of a phosphate group.
4.1 Chemical Energy and ATP
Describe the relationship between energy stored in food
and ATP.
1. Food molecules store chemical energy in their bonds.
2. Food is broken down into smaller molecules that are
broken down further to transfer this energy to ATP.
4.1 Chemical Energy and ATP
Organisms break down carbon-based molecules to
produce ATP.
• Food does not contain readily useable ADP that our cells
can use.
• Food has to be eaten and digested first (making smaller
molecules)
• Different foods contain different amounts of calories,
which is a measure of energy. Calories and ATP are
related.
• Different foods contain different amounts of ATP.
• The number of ATP molecules produced depends on the
type of molecule that is broken down
– Carbohydrate
– Lipid
– Protein
4.1 Chemical Energy and ATP
Carbohydrates are the molecules most commonly broken
down to make ATP.
– not stored in large amounts in
our bodies
– you can get up to 36 ATP
molecules from one glucose
molecule
adenosine
triphosphate
tri=3
adenosine
di=2
diphosphate
4.1 Chemical Energy and ATP
• Lipids or Fats store the most energy and provide the
most ATP when broken down.
– Store 80 percent of the energy in your body
– Obtain about 146 ATP molecules from a triglyceride
• Proteins are least likely to be broken down to make ATP.
– amino acids not usually needed for energy, but for making
new proteins!
– store about the same amount of energy as a carbohydrate
4.1 Chemical Energy and ATP
A few types of organisms do not need sunlight and
photosynthesis as a source of energy.
• Some organisms live in places
that never get sunlight
(hydrothermal vents)
• These vents release chemical
compounds
• In chemosynthesis,
organisms use chemical
energy instead of light energy
to make energy-storing
carbon-based molecules.
• Process is
– similar to photosynthesis
– uses chemical energy
instead of light energy