Unit Test 2 Cellular Energy Flashcards
(37 cards)
What type of system are living things classified as?
Open systems
Open systems exchange matter and energy with their environment.
What are the stages of energy flow in an ecosystem?
- sun
*Plant - Primary Consumer
- Secondary Consumer
- Decomposers
These stages illustrate how energy is transferred through different trophic levels.
What does the First Law of Thermodynamics state?
Energy cannot be created or destroyed
It can only be transformed from one form to another.
No energy transfer is completely efficient. Some energy is lost as..
Heat
What is the second law of thermodynamics
Energy transfer increases the entropy of the universe.
What is entropy?
Measure of disorder. Reduces ammount of usable energy available to do work. Living things are highly ordered, they have low entropy.
A high degree of organization (low entropy) is maintained by a constant output of ____.
Energy.
What is energy?
Capacity to cause change. State that can be quantified and measured. Can be transferred from one point to another.
Explain and name the two types of energy
Potential: energy that matter possesses because of its position or structure.
Kinetic: energy associated with motion.
Give an example of KE and PE
PE: chemical energy available for release in a chemical reaction.
KE: thermal energy associated with random movements of atoms or molecules.
What’s mechanical energy?
The TOTAL energy an object has, KE and PE combined.
What is metabolism?
Metabolism refers to all the chemical reactions that are required to maintain cells.
Ex. Catabolic and Anabolic reactions.
What’s the difference between a catabolic and anabolic reaction?
Catabolic: breaks bonds between molecules. Hydrolysis/digestion.
Anabolic: forming bonds between molecules. Dehydration synthesis and synthesis.
Explain a metobolic pathway
Begins with a specific molecule and ends with a product. The product of one is the substrate of the next, each step is catalyzed by a specific enzyme.
Explain Gibbs free energy
The ammount of usable energy of a system. Energy available to do work. Affected by temperature and pressure of a system.
Explain the change in Gibbs free energy equation
Describes the maximum usable energy released or absorbed. From initial to the final state.
Delta G = Delta H - T Delta S
Delta G: change in Gibbs free energy
D H: change in enthalpy.
D S: Change in entropy
What happeneds if if Delta G is 0?
The reaction is in a state of equilibrium
What’s an exergonic reaction?
When the free energy of the products is lower than the reactants. (DG<0)
Chemical reactions that release energy.
Reaction occurs spontaneously.
Example: digestion polymers
What’s an endergonic reaction?
When the free energy of the products is higher than the reactants (DG>0)
Chemical reactions that require input of energy.
Reaction occurs non spontaneously.
Ex: building polymers
What’s energy coupling?
Cells store chemical energy in biological molecules.
Digest these molecules and harvest the energy for cellular work.
Organisms couple exergonic reactions with endergonic reactions.
What does ATP stand for?
Adenosine triphospate
What is ATP?
Energy currency of the cell.
Most abundant short term energy storing molecule.
Renewable and re usable.
What is the structure of an ATP?
RNA nucleotide.
Made of: ribose sugar. (Pentose sugar)
Adenine: nitrogenous base
3 phosphate groups
Describe ATP function.
ATP releases energy when the bonds between the second and third phosphate groups are broken. This forms a molecule called diphosphate. (ADP) and an inorganic phosphate (Pi)
Hydrolysis causes this reaction.
