Unit 2 - Metabolism and energy Flashcards
What is life
a constant flow of energy and organisms capture energy and use it for work
Metabolism
is the sum of all chemical rxn in a cell or organism
What is energy
the ability to do work (transfer of energy from one place to another) called thermodynamics
1) kinetic
2) potential energy
Kinetic
energy of motion (electrical)
Potenital energy
stored energy and is dependent on objects location or chemical structure (gravitational)
Metabolism
all chemical process
1) catabolic
2) anabolic
Catabolic rxn
energy is released + complex mol r broken down to simpler mol
ie. cellular respiration
Glucose + oxygen = carbon dioxide + water + energy
Anabolic rxn
energy is absorbed + simpler mol combine to build mol more complex
ie. protein synthesis
amino acid + amino acid = protein + water
active or catabolic
a) protein synthesis
b) digestion
c) DNA synthesis
d) photosynthesis
3) cellular respiration
a) anabolic
b) catabolic
c) anabolic
d) anabolic
e) catabolic
First law of thermodynamics
“energy cannot be created or destroyed but converted into another form”
ie. ingests food
First low of thermodynamics pt 2
during cellular respiration, the energy in the bonds of glucose is released and is transformed into new mol, motion, and heat energy
Second law of thermodynamics
“in every energy transfer or conversion, some of the useful energy is the system bc unusable and increases the entropy of the universe
-never = 100%
-conversion to heat fate of chemical energy
Entropy
is a measure of the amt of randomness disorder in a system
example of second law of thermodynamics
cleaning your room is highly ordered (low entropy). Eventually your room bc messy (high entropy) therefore u need to clean it (lots of energy)
work=total energy-heat
Catabolic rxn
always increases entropy
chemical rnx entropy increase when
- solids react from liquids or gaeses
-liquids react to form gasesous products - the total number of product mol is greater than the total number of reactant mols
an arm raised increase or decrease in entropy
decrease bc potential energy is increased
a cell divides increase or decrease in entropy
increase as the system is bc more random of the cells free energy used in cell division.
Free energy
the amt of energy that can do useful work, not a not deltG = H -TS
delta G =
H =
T =
S =
TS =
delta G= energy available to do work
H = enthalpy of total energy
T = temperature in K
S = entropy
TS = energy not available to do work
Heat of Reaction
is calc by the difference in bond enrgies (energy consumed when bonds break - energy released when bond form)
delta G = Gfinal state - Ginital state
Definition of Free Energy
-spontaneous process
- concept of free energy provides a criterion for measuring spontaneity
Enthalpy definition
a measure of the total potential energy expressed as a heat reaction (delta H)
Free energy in depth
- decrease in E gives up energy and an increase in E contributes to spontaneity of a process
- higher temp enhances effect of an entrophy change
delta G < 0
Delta G > 0
Delta G = 0
<0 spontaneous, exergonic rxn.
>0 not a spontaneous endergonic rxn
=0 reaction at equilibrium
Types of rxn
Exergonic vs endergonic
Exergonic rxn
chemical rxn that releases free energy; the product have less free energy.
- decrease gibbs free energy
- increase in stability
- spontaneous
- downhill, moving towards equilibrium
- give off energy
Endergonic rxn
a chemical reaction that absorbs free energy the products have more free energy than the reactant
- decrease stability
- not spontaneous
-movement away from equilibrim
-anabolic
Exergonin rxn fuels Endergoninc rxn
ie. you build muscle by + amino acids together to make muscle fibres (needs energy). you have just eaten a healthy snack filled w nutrients and your digesting it as we speake (releasing energy)
Coupled Rxn
the transfer of energy from one rxn to another in order to drive secondrxn
- exergonic rxn release free energy therefore can proceed spontaneously
- endergonic rxn need a supply of free energy and cannot procced on their own.
If the activation energy of a reaction is 1250kj/mol and the energy released by the formation of products in the rxn is 1186kj/mol what type of rxn has taken place
exergonic bc there is less enrgy in the products; delta G is -
is an anabolic rxn more likely to be exergonic or endergonic
endergonic
would this type of rxnhave a + or - value for delta G
positive delta G
How is the melting of ice is an increase in entropy
ice is organized into a tight lattice of water mol w intermolecular hydrogen bonding. when ice melts, the water mols r randomly moving over one another in the liquid state and r less organized hence an increase in entropy
