Energy & metabolism Flashcards
How is energy from sunlight stored?
-Stored as potential energy in covalent bonds between atoms in the sugar molecules
How is the strength of the covalent bond measured?
-By the amount of energy that’s required to break it
What happens to the energy stored in chemical bonds during a chemical reaction?
-The energy is used to make new bonds
What is it called when an atom LOSES an electron?
-Oxidation bc oxygen is the most common electron receptor in biological systems
What is called when an atom GAINS an electron?
-Reduction= the reduced form of a molecule has HIGHER energy that oxidation form
What are Redox Reactions?
- When oxidation & reduction take place together
- Play a key role in the flow of energy in biological systems
What is Energy defined as?
-The ability to do work
What does the First Law of Thermodynamics state?
- Energy cannot be created nor destroyed, it can ONLY change from one form to another
- The total amount of energy in the world remains constant
What is Heat?
- Energy that dissipates into the environment
- A Measure of the random motion of molecules
How does Energy flow in the biological world?
-In one one direction w/ new energy from the sun constantly entering the system to replace the energy that’s been dissipated into heat
What is a heat gradient?
-The temperature difference between 2 areas
How can heat be harnessed to do work?
- ONLY when there is a heat gradient present
- But CAN’T work in cells bc they’re too small so cells must rely on chemical reactions for energy
How does the energy available to do work decreases?
-It decreases due to the increasing loss of being turned into heat
What is the 2nd Law of Thermodynamics?
- States that disorder (entropy) is constantly increasing= you CAN’T keep all the useful energy which is why perpetual motion is impossible
- ONLY low to high entropy NEVER high to low entropy
What is Entropy?
- The disorder in the universe
- Low quality, unusable energy
What is Truely High Entropy?
-The entropy state would NOT be distinct
think of different paint colors mixing together to create a different color
What is Low Entropy?
-The entropy state would be MORE distinct= can see a more clear separation
(can see the green and the blue before making purple)
what are the equations expressing the 1st & 2nd law are limited to?
-ONLY applies to ISOLATED systems bc biological systems are open systems