Free Energy

     On earth, in order for living organisms to maintain life, all living systems require energy. Energy is a very interesting topic because without energy we would not have any order, growth, or reproduction. Although not all organisms use the same methods to maintain order, energy will always be required for that matter. In fact, organisms use various energy-related strategies to survive; For example, some include different metabolic rates, physiological changes, and variations in reproductive and offspring-raising strategies. With the lack of energy this would cause devastating deficiencies to individual organisms, also the changes in free energy can impact heavily the population size and cause huge disturbances at the ecosystem level.

        There have been many methods to capture, use and store free energy that have evolved within organisms. Cells are able to capture free energy through two methods either photosynthesis or chemosynthesis. Autotrophs, who are your plant organisms feed themselves by capturing free energy from the environment, including the energy that comes from the sun and chemical sources. On the contrary heterotrophs harvest free energy from carbon compounds produced by other organisms. So the difference between autotrophs and heterotrophs is simply that autotrophs provide themselves with food (energy) and heterotrophs rely on other organism for their income as food (energy). Photosynthetic organisms capture energy present in  sunlight while chemo-synthetic organisms capture free energy from small inorganic molecules present in their environment  and this can happen in the absence of oxygen these are two methods used by autotrophic organisms. Heterotrophs metabolize carbohydrates,lipids, and proteins by hydrolysis as a source of  free energy.

Willard Gibbs

If you take a took to the left, you will see one of the most profound men in science. This genius by the name Willard Gibbs is responsible for the Gibbs free energy equation used in thermodynamics. the Gibbs free energy is a thermodynamic potential that measures the "usefulness" from a thermodynamic system at a constant temperature and pressure.To get a better understanding of Gibbs equation you must know the laws of thermodynamic. The laws of thermodynamics define the laws which temperature,energy, and entropy go under.The first law of thermodynamics which is also known as the law of conservation of energy states that energy cannot be created nor destroyed. The second law of thermodynamics says that the entropy in any isolated system not in thermal equilibrium almost always increases. The third law says that the entropy of a system approaches a constant value as the temperature approaches an absolute zero. Entropy is the lack of order within a thermodynamic system and enthalpy is a thermodynamic quantity that shows the total heat content of a system.

that energy cannot be created or destroyed in a chemical reaction.

Source: Boundless. “The Three Laws of Thermodynamics.” Boundless Chemistry. Boundless, 16 Nov. 2014. Retrieved 30 Nov. 2014 from https://www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/thermodynamics-17/the-laws-of-thermodynamics-123/the-three-laws-of-thermodynamics-496-3601/

that energy cannot be created or destroyed in a chemical reaction.

Source: Boundless. “The Three Laws of Thermodynamics.” Boundless Chemistry. Boundless, 16 Nov. 2014. Retrieved 30 Nov. 2014 from https://www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/thermodynamics-17/the-laws-of-thermodynamics-123/the-three-laws-of-thermodynamics-496-3601/

Gibbs free energy equation.

The AP Biology curriculum framework 2012-2013 is a great guide for such a hefty topic. I would suggest for you to click the link below. The curriculum gives a satisfying in depth understanding to the growth, reproduction, and maintenance of organization of living systems requiring free energy and matter. Once you click the link below follow through pages 15-22 for extra details such as the the whole process of different energy-related pathways in biological systems. 






 AP Biology Curriculum Framework 2012-2013



Sources

 AP BIOLOGY (n.d.): n. pag. Web.

 

"No. 119: J. Willard Gibbs." No. 119: J. Willard Gibbs. N.p., n.d. Web. 30 Nov. 2014.

 

 

"Chemical Thermodynamics." Gibbs Free Energy. N.p., n.d. Web. 30 Nov. 2014.

 

"Gibbs Free Energy." Gibbs Free Energy. N.p., n.d. Web. 29 Nov. 2014.

2.B.1

·      Discuss how cell membranes separate the internal environment of the cell from the external environment of the cell. Cell membranes separate the internal environment of the cell from the external environment of the cell by selective permeability being a direct consequence of membrane structure.

·      Cells are selectively permeable. Discuss each point below and how it allows the cell to be selectively permeable.

o   Discuss the following structures and the role the play in the cell membrane: phospholipids, embedded proteins, cholesterol, glycoproteins and glycolipids phospholipids give the membrane both hydrophilic and hydrophobic properties. Embedded proteins can be hydrophilic, with charged and polar side groups, or hydrophobic, with nonpolar side groups. Cholesterol help maintain the cells membranes fluidity. Glycoproteins are membrane protein with bound. Glycolipids serve as markers from cell to cell membrane.

o   Discuss the properties of a phospholipid (hydrophobic/phallic, polar/non, and fatty acids/phosphates. The hydrophilic phosphate portions of the phospholipids are oriented toward the aqueous external or internal environments, while the hydrophobic fatty acid portions face each other with the interior of the membrane itself.

o   Embedded proteins – how do they allow transport? Embedded proteins transport through active transport. Active transport is when proteins embedded in the cell's lipid bilayer. Those proteins do much of the work in active transport. They are positioned to cross the membrane so one part is on the inside of the cell and one part is on the outside. Only when they cross the bilayer are they able to move molecules and ions in and out of the cell.

o   Discuss which molecules can easily pass through the membrane and which can’t. Why? Water and oxygens and smaller molecules can go through.

·      Cell walls are a structural boundary that provides extra barrier for some organisms.

o   Discuss the cell wall of plant cells, prokaryotes and fungi, and what they are composed of. Plant cell walls, prokaryotes and fungi are made up of cellulose.

2.B.2

·      Passive transport does not require the input of energy; the net movement of molecules is from high to low. Discuss the following factors relating to passive transport.

o   Discuss how primary transport allows for export of waste. Primary transport allows for the export of waste by the movement of molecule down the concentration gradient. From an area of high concentration to low concentration.

o   Discuss how membrane proteins play a role in facilitated diffusion of charged/polar molecules in the membrane. Use the examples of glucose and Na/K transport. Membrane proteins play a role in facilitated diffusion of charged and polar molecules through a membrane example of this are glucose transport and na+/K+ transport.

o   Discuss the following solutions and their effect on a cell. Hypotonic, hypertonic, and isotonic. Hypotonic solutions have a higher water concentration and lower solute concentration. Hypertonic solutions have a lower water concentration and a higher solute concentration isotonic solution is equal for both.

o   Discuss water potential and the formula for solving for it. Water potential is just potential energy of water relative to pure water. The formula for solving is just solute potential plus the pressure potential.

·      Active transport requires free energy to move molecules against their concentration gradient from areas of low to high. Discuss the following factors relating to active transport:

o   Discuss where the free energy used in active transport comes from.

o   Discuss the membrane proteins needed for active transport.

o   Explain how molecules are moved against their concentration gradient. Use the example of the Sodium Potassium Pump. 

o   Discuss the difference between endocytosis and exocytosis.

§  What happens in each? Endocytosis in inside and exocytosis is outside of the cells what occurs is in endocytosis is the cellular uptake of biological molecules and particulate matter via formation of new vesicles from the plasma membrane. Exocytosis is the cellular secretion of biological molecules by the fusion of vesicles containing them with the plasma membrane.  

§   

o   Discuss the difference between pinocytosis and phagocytosis. Pinocytosis is the drinking and phagocytosis is the eating inside the cell membrane.

2.B.3

·      Discuss how internal membranes facilitated cell process by minimizing competing interactions by describing the activities of the lysosome.

·      Membranes and membrane bound organelles in eukaryotic cells processes. Discuss each of the following and how they compartmentalize: ER, mitochondria, chloroplast, Golgi, and nuclear envelope.

·      Discuss how prokaryotic cells function since they have no membrane bound organelles.