Exam(2) (5) - Metabolism Flashcards
What is metabolism?
All the chemical reactions by which cells get and use energy.
- SUM OF ALL CHEMICAL REACTIONS
What is life in the context of energy?
A constant flow of energy channeled by organism to do the work of living.
aA + bB————–> cC+dD
<————–
reactants <———>products
What is energy?
The ability to do work
What are examples of potential energy?
Potential = stored
- magnetic
-gravity
-chemical *
What are examples of kinetic energy?
kinetic= move
- mechanical *
- light
- heat
How many directions does energy flow?
In one direction
What kind of energy is associated with producers?
Chemical
What kind of energy is associated with Consumers and Decomposers?
Mechanical
What is metabolic heat?
body heat ( a waste product)
Where does all energy go eventually?
back to the enviroment
What is the 1st Law of Thermodynamics?
Law of Conservation of Energy
- E cannot be created or destroyed
- E can be changed from one form to another
-Total E in the universe is constant
What is an example of the 1st law of thermodynamics?
chemical –> mechanical
What is the 2nd Law of Thermodynamics?
Law of Entropy
- When energy is changed from one form to another there is a loss of usable energy
-waste energy goes to increase disorder ( entropy)
- every cellular process increases the total entropy in the universe
Which has more entropy C6H12O6 or CO2 + H2O
CO2 + H2O
- less organized
- more stable
- more entropy
What are reactants?
participate in reactions
What are products?
form as result of reaction
What is Free Energy ( gibbs)
Amount of energy available to preform work
H=G + TS
enthalpy = usable E + unusable E
What is are Exergonic Reactions?
Products have LESS free energy than its reactants.
- delta G is negative
- spontaneous
- favor product
- energy releasing
- BREAK
What are endergonic reactions?
Products have MORE free energy than its reactants.
- delta G is positive
- MAKE
-favor reactants - needs input of energy
What is the delta G of ATP
-7.3 kcal ( exergonic)
What is ATP?
Adenosine Triphosphate
- made from ADP + P
- high energy
- constantly generated/ NONE stored
- always made on demand
What is ATP used for?
- chemical work- synthesis macromolecules
-mechanical work- pump substances
- transport work- contract muscles
What are Metabolic Pathways?
linked reactions - cascade
- reactions that happen in sequence
- products are reactants of next
- proceeds through several intermediates and ends with different product
What is the difference between a cycle and a pathway?
Pathway: start and end are different
Cycle: start and end are the same
What is a metabolic turnover?
coupling of endergonic and exergonic reactions.
Catabolism ( catabolic reactions)
Energy releasing = Exergonic
- harvest energy to make/transfer chemical bonds.
Anabolism ( Anabolic reactions)
Energy requiring = Endergonic
- expend energy to make/transform chemical bond
