Metabolism Flashcards
What’s metabolism?
Totality of an organisms total reactions.
Metabolic pathway how it begins
Begins with a specific molecule, a reactant, which is altered in a series of chemical reaction steps, resulting in a certain product.
Each step is catalyzed by a specific enzyme
catabolic pathways
Catabolic pathways release energy by breaking down complex molecules into simpler compounds
EX) Cellular respiration
Anabolic pathways
Anabolic Pathways consume energy to build complex molecules from simpler ones. the synthesis of amino acids is an example of anabolism.
Bioenergetics
It is the study of how organisms manage their energy resources.
Kinetic energy
an energy associated with motion
Heat (thermal energy)
Is kinetic energy associated with random movement of atoms or molecules
Potential energy
Energy that matter possesses because of its location or structure.
Chemical energy
Potential energy available for release in a chemical reaction
Thermodynamics
the study of the energry transformations that occur in a collection of matter, or organisms.
First Law of Thermodynamics (the law of conservation of energy )
States that energy of the universe is constant: Energy can be transferred and transformed, but it cannot be created or destroyed.
First law of thermodynamics example
Plants are not energy producers they are energy transformers. They transform light energy into chemical energy.
The Second law of thermodynamics
In every energy transformation some energy becomes available to do the work and other energy unavailable or lost.
Work is Gibb’s Free Energy
Gibb’s Free Energy Neg -
When ^G is negative the system will do work on he surroundings and is spontaneous
Ex combustion of octane in a car releases enough energy to move the piston
Gibb’s Free Energy Pos+
When Positive system needs to do work on the system and is not spontaneous
EX) H20 (g) -> H20 (l) the surrounding pressure on the gaseous water must be increased or the surrounding temp must be decreased so water can turn from gas to liquid
Release of Heat
in most transformations energy is converted into heat and in a living cell heat cannot be used to do work it is only used to warm the organism.
Enthalpy
Heat absorbed or released
Enthalpy Neg-
System will release heat energy and is exothermic or exergonic
Enthalpy Pos+
System will absorb heat energy and is endothermic or endergonic
First Law of Thermodynamics
The net energy changes of the universe increase the net entropy of the universe
No process of energy transformation is ever 100% efficient; some energy will always be lost in the form of heat
Metabolism
the sum of all chemical reactions that occur in a cell or organism; metabolism manages the material and energy resources of the cell.
chemical work
pushing of endergonic reactions that would not occur spontaneously, such as building polymers from monomers.
Transport work
the pumping of substances across a membrane against the direction of spontaneous movement
mechanical work
cellular processes that requires movement; beating of cilia, the contraction of muscles
Are enzymes affected by chemical reactions ?
No this is why enzymes can be used over and over again.
Enzymes are what?
Proteins but there are a few made of RNA called riboenzymes
Activation energy
the amount of energy in order to get molecules to react with another
Activation energy is usually…
thermal energy that speeds the movement of atoms and molecules
Too much heat to an enzyme will…
denature it
To reduce the amount of activation energy…
enzymes are used
How do enzymes work?
They allow reactions to occur under favorable, cellular conditions by brining reactants of chemical reaction into contact with one another
Each enzyme had a unique 3d shape which is why…
a substrate hast to be so specific to an enzyme.
Substrate
The specific reactant (or sometimes 2 or more reactants) that an enzyme acts on.
Active site
Small portion of the enzyme that interacts with the substrate
When the enzyme binds to its reactants it is referred to as
the enzyme substate complex.
enzyme fit models
2 Enzyme models
Lock and key And Induced fit
Lock and Key model
Substrate and enzyme fit perfectly
Induced fit
Substrate attaches to the active site it induces a slight change in the enzyme’s shape so the enzyme fits more snuggly around the substrate
the rate of the reaction is the…
amount of product produced per unit of time
substrate concentration
If the substrate concentration is increases then the enzyme has more substrate to work on and as a result the reaction rate would increase(as time goes on reaction rate levels off)
Enzyme concentration
Enzyme concentration increases so does reaction rate because more enzymes to carry out reactions.
Would also level off eventually
Optimal pH
Each enzyme has a pH they work best at.
An enzyme in its optimal pH the enzymatic rate would increase and be at its highest, but if placed in lower or higher than optimal the enzymatic rate would decrease.
enzyme temperature
Has a temp it works best at.
Reaction rate increases with heat but if too hot it will rapidly decrease.
At high temps an enzyme can also denature.
If placed in cold it will decrease but will not denature.
