Cell Bio Final Flashcards
What is an anabolic reaction?
Process of building molecules. ex protein synthesis
What is a catabolic reaction?
Process of breaking down molecules. ex breaking down triglycerides for energy
Where do we find energy in ATP or GTP molecules?
Available energy is containted in the bonds between phosphates and is released when they are broken through hydrolysis (adding a water molecule)
6 forms of energy in cells
- synthetic work
- mechanical work
- concentration work
- electrical work
- heat
- bioluminescence and fluorescence
Synthetic work definition and example
Change in chemical bonds, formation of bonds through building larger macromolecules.
Ex. proteins, lipids, carbs - glycogen
Biosynthesis definition
- Biosynthesis: formation of new chemical bonds + synthesis of new chemical molecules
- Increase in cell size as a consequence
Mechanical work definition
- Change in location/orientation
- any part of the cell generating movements
ex. enzymes
Concentration work definition
- Moving molecules/solutes against their concentration gradient
- Molecules that can move across the membrane
Electrical work def
- Similar to concentration work except this process involves the movement of ions
- example: establishment and maintenance of membrane potential
Heat definition
By product of converting potential energy to kinetic energy
- ~60% of energy from ATP production is “lost” as heat
ex shivering
Bioluminescence & Fluorescence
Bioluminescence: Production of light via ATP or chemical oxidation
- Fluorescence: Production of light after absorbing light at a different wave length
- examples: fireflies, some jellyfish, luminescent mushrooms
First law of thermodynamics
- Law of conversation of energy
- you can no create nor destroy energy, just change its form
- “in every physical or chemical change, the total amount of energy in the universe remains constant”
- eg. potential to kinetic and/or heat
Second law of thermodynamics
- in every chemical or physical change, the universe always tends towards greater disorder
- Disorder = entropy (S)
second law tells us:
- in which direction a reaction will proceed
- energy released
- how certain condition affect the reaction
Endo vs exothermic
Endo: requires energy to be added
eg. photosynthesis
Exo: releasing energy
eg. oxidation of glucose
Gibbs Free Energy
ΔG = ΔH - TΔS
G= gibbs free energy H= enthalpy T= temperature S= Entropy
ΔG < O: Exergonic, releases energy
ΔG > 0: endergonic, requires energy
ΔG = 0: equilibrium
Redox reaction = reduction & oxidation
Oxidation: removing/loss of electrons
Reduction: addition/gain of electrons
always coupled reactions
often involves transfer of hydrogen atoms rather than free electrons
How do humans obtain energy?
Breakdown of food: glucose/sugars to get energy
Activation energy
the minimum amount of energy required in order for the reactants to react and give rise to the final product
Transition state
- intermediate stage where free energy is greater than that of initial reactants
Metastable state
- state in which molecules in a cell are thermodynamically favorable but stable and have inefficient energy to exceed the EA barrier
- reactants are in a metastable state
Reaction speed
More molecules have enough energy to undergo the reaction due to changing temperature
Catalysts
Organic catalysts will increase the reaction speed 10^7 to 10^17 times
Catalyst: a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change
Basic properties of all catalysts
- lower the activation energy
- formation of transient and reversible complexes with substrates
- change only the rate
- Almost all catalysts within cells are organic (mostly protein enzymes)
Active site
- where substrate/reactant binds and reaction occurs
- made of amino acid (R groups)
- form transient bonds with substrate
- enzyme is specific for the substrate and reaction
