ATP and Energy

Forms of Energy

• To understand the cell completely we have to define how it gets energy and how it uses that energy

• Energy is the capacity to cause change or do work

Forms of Energy

• Kinetic energy is the energy of motion

• Moving objects can perform work by transferring motion to other matter

• Heat is a type of kinetic energy that is transferred among randomly moving atoms

• Light is another type of kinetic energy

Forms of Energy

• Potential energy is energy that matter posses as a result of its location or structure

• This is stored energy that can be released at any time

• Chemical energy is the potential energy available for release in a chemical reaction

Thermodynamics

• Thermodynamics is the study of energy transformations that occur in a collection of matter

• In thermodynamics everything that is being studied is called the system

• Everything else in the universe is the surroundings

Thermodynamics• There are three laws of

thermodynamics– We only care about two of them

• The first law of thermodynamics states energy in the universe is constant

• This means that energy can be transferred and transformed but not destroyed

• This means that a power plant does not create energy, it converts it from one form to another

Demo

Thermodynamics

• The second law of thermodynamics states that conversions of energy create entropy of the universe

• Entropy is the random disorder or randomness in the universe

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Exergonic and Endogenic

• Exergonic reactions are reactions that release energy

• Exergonic literally means energy outward

• Endergonic reactions are reactions that yield products rich in potential energy

• Endergonic means energy inward

ATP

• ATP (adenosine triphosphate) is a molecule that is vitally important to a cell

• It powers nearly every cellular function

• The name tells us how it is built

ATP

• Because of how it is structured it is often compared to a loaded spring

• All three phosphate groups are negatively charged, so they repel each other

ATP

• As a result the bonds can be broken by hydrolysis

• The hydrolysis of ATP is exergonic

• The energy that is released can be used to power other parts of the cell

ATP

• The phosphate group that leaves can be transferred to another molecule

• When this happens we transfer energy from an exergonic reaction to an endergonic reaction

• This is called phosphorylation

ATP Work

• There are three main types of work that ATP does– Chemical– Mechanical– Transport

ATP Work

• In chemical work the phosphorylation of reactants provides energy to drive the endergonic synthesis of products

• That’s a lot of fancy words that basically mean it helps create a potentially strong molecule

ATP Work

• In mechanical work the transfer of phosphate groups into motor proteins allows cells to change protein shape

• This physically moves cells and allows them to change shape and pull or push

ATP Work

• In transport work transport proteins use ATP to drive the cell membrane pumps that pump molecules across a concentration gradient

• This phosphorylation of transport proteins allows cells to move molecules across their membranes