Untitled Flashcards Set

Define 'energy'.

1. The capacity to do work (to cause Change) Potential and Kinetic Energy

Compare potential energy and kinetic energy. Classify different energy forms into one of these two categories.

1. Potential is stored energy. Kinetic energy is motion energy. 

2. Potential

   1. Chemical Energy - stored in bonds and atoms

   2. Concentration Gradient - stored across membrane

3. Kinetic

   1. Electrical Energy

   2. Radiant Energy

   3. Thermal Energy

   4. Motion Energy

Explain why cells need energy? Describe the types and examples of cellular work.

1. All living systems require Energy

2. Synthetic Work - Biosynthetic pathways

3. Mechanic Work

4. Concentration Work

5. Electrical Work

6. Generation of Heat 

7. Generation of Light 

Define an organism based on its energy-converting abilities (e.g. autotroph, heterotroph, chemotroph, phototroph, photoautotroph, chemoheterotroph).

1. Autotroph - organism that produce organic compounds form inorganic molecules

2. Heterotrophs - organisms that produces organic compounds starting from other organic molecules

3. Phototroph - able to capture light E and transform into chemical E

4. Chemotroph - obtains energy by oxidizing bonds in molecules

Explain how energy and matter are used in the biosphere. Specifically explain this statement: "Energy flows through the biosphere while matter is recycled". Explain why energy must be replenished (i.e. heat loss). 

1. Energy flows through biosphere

   1. Flow from sun to earth

   2. Light energy captured by photoautotrophs used to convert inorganic C into organic C

      1. Some Energy lost as heat

   3. Chemotrophs and autotrophs convert organic C into usable E.

2. Matter cycles in Biosphere 

   1. Between phototrophs and heterotrophs 

3. Plants do not make energy from the sun, they convert the energy. 

Define 'thermodynamics'.

1. The study of Energy transformations. Energy can be converted from one form to another. Cells/organisms extract E and use it to perform work

Interpret the first law and second law of thermodynamics. Provide examples to illustrate these laws.

1. First Law: Energy can be transferred and transformed. Energy cannot be created or destroyed

2. Second law: Every Energy transfer or transformation increases entropy (disorder) of the universe 

Define free energy. Define a 'spontaneous' process. 

1.  Delta G = change in free energy

   1. Measure of thermodynamic spontaneity of a system. 

   2. Amount of Energy available to do work

   3. Looking at change in system from start to finish

What does deltaG tell us about a system? What does it mean if deltaG is zero?

1. Gibbs free energy tells us whether a process can occur

   1. To what extent (directionality)

   2. Wont tell us if a process will actually occur

Interpret the meaning of the following equation: ∆G = ∆H - T∆S. 

1. Delta g is the change in free energy, spontaneity of a system

2. Delta h is change in enthalpy or the heat content of a system

3. Delta s is change in entropy or disroder of a system

4. T = temperature (kelvins)

5. If delta G is less than zero it is spontaneous and exergonic, and if it is greater than 0 it is non spontaneous and endergonic

What happens when deltaG = 0?  Explain.

1. It is at equilibrium and it is most stable

2. We cannot do work by a system at equilibrium

Interpret a free energy diagram. 

1. yes

Be able to determine for given conditions whether a reaction can proceed spontaneously.

1. If free energy decreases then it is spontaneous 

Define endergonic and exergonic. How do these terms related to deltaG values?

1. Exergonic is energy released. This is negative delta G

2. Endergonic is energy required. This is positive delta G

Provide examples of a spontaneous change.  How does the initial state of the system compare to the final state?

1. Jumping off of a diving board, diffusion, and chemical reaction. The initial state has more energy compared to the final   state.