genbio2.3

• Cells use energy that is stored in the bonds of certain organic molecules.
• Life processes sses require a constant supply of energy.
• Adenosine triphosphate (ATP) is a molecule that transfers energy from the breakdown of food molecules to cell processes.
• Adenosine triphosphate (ATP) is the most important biological molecule that supplies energy to the cell.
• A molecule of ATP is composed of three parts bonded together by "high energy bonds: A nitrogenous base (adenine)
• A molecule of ATP is composed of three parts bonded together by "high energy bonds: A sugar (ribose)
• A molecule of ATP is composed of three parts bonded together by "high energy bonds: Three phosphate groups (triphosphate)
• formula of ATP: C10H16N5O12P3
• ATP comes indirectly from the food that we eat.
• Molecules of carbohydrates (glucose) and lipids are broken down through the process of cellular respiration to produce ATP.
• The part of the cell which produces ATP is mitochondria
• ATP-ADP Cycle

  • The energy stored in ATP is released when a phosphate group is removed from the molecule.
• ATP-ADP Cycle

  • ATP has three phosphate groups, but the bond holding the third phosphate groups is very easily broken. When the phosphate is removed, ATP becomes ADP (adenosine diphosphate)
• ATP-ADP Cycle

  • A phosphate is released into the cytoplasm and energy is released.
• ATP-ADP Cycle

  • ADP is a lower energy molecule than ATP, but can be converted to ATP by the addition of a phosphate group.
• ATP-ADP Cycle

  • ATP ADP phosphate + energy available for cell processes
• Steps in ATP-ADP Cycle

  To supply cells with energy, a "high energy" bond in ATP is broken. ADP is formed and a phosphate is released back into the cytoplasm.
• Steps in ADP-ATP Cycle

  As the cell requires more energy, ADP becomes ATP when a free phosphate attaches to the ADP molecule. Then energy needed to create an ATP molecule is much less than the amount of energy produced when the bond is broken
• How do you "recharge" the battery?

  • ADP is continually converted to ATP by the addition of a phosphate during the process of cellular respiration.
• How do you "recharge" the battery?

  • ATP carries much more energy than ADP.
• How do you "recharge" the battery?

  • As the cell requires more energy, it uses energy from the breakdown of food molecules to attach a free phosphate group to an ADP molecule in order to make ATP
• When is ATP used?

  
  

  In this way ATP transfers energy between separate biochemical reactions in the cell.

  • ATP is consumed in the cell by energy-requiring processes and can be generated by energy-releasing processes.
• ATP is the main energy source for the majority of cellular functions.This includes the production of organic molecules, including DNA and, and proteins. ATP also plays a critical role in the transport of organic molecules across cell membranes, for example during exocytosis and endocytosis.
• Types of Reactions

  Exergonic (energy-yielding)

  Produces ATP

  • Ex. Cellular respiration
• Types of ReactionsEndergonic (energy-requiring) reactionsRequires ATP-Ex. Photosynthesis
• ATP - Main energy source for the cell and Contains 3 phosphate groups (triphosphate)
• ADP - Contains Less energy and Contains 2 phosphate
• Energy is the capacity to cause change. It is also the ability to rearrange a collection of matter.
• Forms of energy:

  
  

  Kinetic energy associated with relative motion of objects.
• Forms of energy:

  Thermal energy type of kinetic energy associated with random movement of atoms. When thermal energy is transferred in the form of heat.
• Forms of energy:

  Light Energy main energy source is the sun and powers photosynthesis (anabolic process).
• Forms of energy:

  Potential Energy possessed energy of a matter at rest (non-moving form)
• Forms of energy:

  Chemical energy potential energy released in a chemical reaction.
• Thermodynamics is the study of energy transformations that occurs in a system (collection of matter).
• Living systems are considered as open systems because energy and matter are transferred between systems and the surroundings.
• 1st Law: The energy of the universe is constant.

  
  

  Energy can be transferred and transformed but it cannot be created nor destroyed. Plants do not produce energy, but transforms energy from the sun. Some energy becomes unavailable to do work because most is lost as heat. Transfer of energy and transformation makes the matter more disordered. Disorder of matter is measured through entropy.
• 2nd Law: Every energy transfer or transformation increases the energy of the universe.

  
  

  i.e In a room full of people, breathing increases entropy since all are exhaling carbon dioxide. Organisms as open system increase order as long as the order in their surroundings decreases. This shows that as living organism transfers/transforms energy to its surroundings, the disorder increases, thus increases entropy.
• Equilibrium = NO WORK. This usually happened in isolated systems that reach equilibrium.
• A cell that reaches the state of equilibrium is DEAD.
• A normal cell is not in equilibrium, because its products are not accumulated within its system, INSTEAD the products becomes a reactant in the next step.