Chapter 8 Flashcards
cofactor
- inorganic
- permanent or temporary
- sit in active sight to help bonding of enzyme
what is ATP
- fit under nucleic acid category
- bond between 2nd and 3rd phosphate contribute to ATP being unstable
what makes up ATP
- 3 phosphates
- base (adenine)
- sugar (ribose)
phosphorylated
phosphate is transferred to a protein
- becomes more reactive and less stable
when is there the most potential energy
longest, weakest bonds
when is there the least potential energy
shortest, strongest bonds
enthalpy
- potential energy of molecule
- effect of molecule on surrounding pressure and volume
exothermic reactions
- release heat energy
- getting energy
- product have less potential energy than reactants
endothermic reactions
-heat energy is taken up
- takes energy
- products have higher potential energy than reactants
entropy
- amount of disorder
- entropy increases
second law of thermodynamics
- total entropy always increases in a system
- example: time only moves in 1 direction
Gibbs free energy
- determines whether reaction is spontaneous or requires energy to proceed
spontaneous reaction
-release energy (exergonic)
- below 0
nonspontaneous reaction
- requires energy to occur (endergonic)
- above 0
energetic coupling
- allows chemical energy released from one reaction to drive another reaction
- one fuels the other
how does energetic coupling work
- energy is produced
- other reactions occur due to the released energy
electron carriers
readily donate electrons to other molecules
NAD+
- accepts 2 electrons plus one proton to from NADH
- nicotinamide adenine dinucleotide
- coenzyme
- electron carrier
FADH2
formed by FAD accepting two electrons plus two protons
why does ATP provide so much energy
due to the structure
- 3 negative charged phosphate groups (lots of potential energy)
how does ADP form
hydrolysis bond between two outmost phosphate groups
what does phosphorylation do to a protein
changes its shape
what is the goal of enzymes
- help molecules get past tension between each other
- provide enough kinetic energy to overcome repulsion between electrons
where do substrates bind to
active site
induced fit
enzyme changes shape of substrates and bring substrates together to form bonds
what bond allows for substrates to bind
hydrogen binds
transition state
- unstable condition; haven’t fully connected yet
activation energy
get substrates to finally link together
what do reaction rates depend on
- kinetic energy of reactants
- activation energy of particular reaction
when do reactions occur
recants have enough kinetic energy to reach transition state
what are the 3 enzyme steps
- initiation- substrates go to active site
- transition state facilitation- substrates start to bond and get over activation hump
- termination- products made
prosthetic groups
- permanently attached to proteins
- force protein or enzyme to change shape
competitive inhibtion
molecule competes with substrate for active site
allosteric regulation
molecule binds at a location other than active site to either activate or deactivate enzyme
metabolic pathways
series of reactions each catalyzed by a different enzyme
- build biological molecules
feedback inhibtion
enzyme in pathway is inhibited by final product of pathway
- slow or increase production
- way enzymes are regulated
electron donor
give electrons
electron acceptor
accepts electrons
energy
- conserved
- can only be transferred or transformed
higher entropy
can rearrange while not changing structure (sand pile)
lower entropy
very few ways to organize without changing shape (sand castle)
