convert enery stored in certain organic molecules to light; in fungus; glow is good to at tracked insects
The totality of an organisms chemical reactions = emergent property that arises from interactions between molecules within the orderly enviornment of the cell; like a giant road map ; manages the material and energy resouces of the cell
begins with a specific molecule, which is then altered in a series of defined steps, resulting in a product ; each pathway is catalyzed by a specific enyzme ADD PIC
metabolic pathway that release energy by breaking down complex molecules into smaller compounds (degrrrradative process); ex. cellular respiration; sugar broken down
consume energy to build complicated molecules from simpler ones; ex. synthesis of protein from amino acids
the study of how energy flows through living organisms
the capacity to cause change; they do work (move matter against opposing forces); the ability to rearrange a collection of matter;
associated with relative motion of objects
heat or thermal energy
kinetic energy associated with the random movement of atoms or molecules
type of energy that can be harnessed to preform work like photosynthesis
not kinetic; energy that matter possesses because of its location or structure; water behind a dam
potential energy available for release in a chemical reaction; glucose high in chemical energy
study of energy transformations that occur in a collection of matter
denotes the matter under study
everything outside the system; the universe
unable to exchange energy or matter with its surroundings; reactions in an isolated system eventually reach equilibrium adn can then do no more work (FILL IN PIC)
energy and matter can be exchanged between system and surroundings
first law of thermodynamics
the energy of the universe is constant; energy can be transferred and transformed but it cannot be created or destroyed. ; principle of conservation of enery
Second law of thermodynamics
in carrying out chemical reactions, living cells unavoidably convert forms of energy to heat. , which is the energy associated with the random motin of atoms or molecules; every energy transfer or transformation increases the entropy of the universe.
measure of disorder or randomness ; in order for a process to occur on its own without outside help, it must increease the entropy of the universe; for a process to occur spontaneously it must increase the entropy of the universe; water can flow downhill spontaneously, but needs force to move upward.
how does the second law of thermodynamics help explain the diffuision of a substance across a membrane?
describe the forms of energy found in an apple as it grows on atree, then falls, an is digested by somene who eats it.
portion of a systems energy that can preform work when temperature and pressure are uniform throughout the system; measure of a systems stability
Change in free energy
= change in systems enthalpy (H) - chang in systems entropy (S) x t (abosulte temp in kelvin)
- change in G
spontaneous ; every spontaneous process decreases the systems free energy
=change in g
G final state- G initial state
higher g to lower g
higher g tends t change to a lower g to become more stable
chemical; when there is no further net change in the relative concentration of products and reactants ; maximum stability
energy outward; ; proceeds with a net release of free energy; ; change in g is negative; chemical mixture loses free energy; occur spontaneously
one that absorbs free energy from its surroundings; stores free energy; non spontaneous; g increases
is metabolism ever at equilibrium?
NOOO. the fact that it is not is a defining feature of life! ex. cell; the constant flow of materials in and outof the cell keeps te metabolic pathways from never reaching equilibrium, and the cell continues to doworkthroughout its life. ; the key to this is that a product of a reaction does not accumulate; but instead becomes a reactant in the next step and waste products are expelled.
Cellular respiration uses glucose and oxyggen, which have high levels of free energy and releases co2 and water, which have low leevels offree energy. i respiration spontaneous or not? is it exergonic or endergonic? what happens to the energy released from glucose?
a key process in metabolism in metabolism is the transport of hydrogen ions across a membrane to create a concentrate gradient. other processes can result in an equal concentration of hydrogen ions on each side. which arrangement of hydrogen ions allows the H+ to preform work in this system.
What three types of work does a cell do?
chemical work (pushing of endergonic reactions- wouldn't have spontaneously)=driving endergonic reactions such as the synthesis of polymers from monomers
transport work (pumping of substances across membranes against the direction of sponataneous movement)
mechanical work: beating of cilia, contraction of muscles and movement of chromosomes etc
a key feature in the way cells manage their energy resources to do work; the use of exergonic process to drive an endergonic one. ; atp is responsible for mediating most energy coupling cells
POWERS CELLULAR WORK!
Breaking it down=exergonic
adenosine triphosphate; contains the sugar ribose; with the nitrogenous base adenine and a chain of three phosphate groups bonded t it.; bonds between phosphate groups can be broken by hydrolyis ; when the terminal phosphate bond is broken , pi leaves the ATP; this reaction is exergonic and releases 7.3 kcal of energy per mol of ATP hydrolyzed; however, conditions in a cell do not conform to normal conditions, so in cellular conditions the change in G is about 13 kcal\mol
Why does ATP provide so much energy?
the triphosphate tail is like a spring; all charges are crowded into the same area and their mutual repulsion contributes to the instable part of the ATP molecule.
How does ATP preform work in the cell?
the cells proteins harness the energy releasedduring ATP hydrolysis in several ways to preform the three types of celular work.
the receipient of the phosphate group; the key to a coupling exergonic and endergonic reactions is the formation of this; the molecule is less stable and more reactive thatn it originally was.
Transport and mechanical work in the cells adn ATP
powered by hydrolysis of atp; atp hydrolysis leads to a change in a proteins shape and often its ability to bind to another molecule.
Regeneration of ATP
organism at work continually uses ATP; ATP can be regenerated by the addition of phosphate to ADP. The free energy required to phophorlate dap comes from exergonic breakdwn reactions catabolism inthe cell; atp cycle moves quickly and a working cell muscle recycles its entire pool of atp in less than a minute.
Regeneration of atp- endergonic or exergonic?
endergonic, because both directions are reversible. ; formation of atp is not spontaneous, free energy must be spent to make it occur. ; catabolic reaction provide this energy.
in most cases, how does atp transfer from exergonic to endergonic reactions in the cell?
Enzymes speed up metabolic reactions by lowering energy barriers.
a spontaneous reaction occurs very slowly. without sucrase, a solution of sucrose dissolved in sterile water will sit for years without hydrolysis, add an enzyme it will be hydrolyzed within seconds.
macromolecule that acts as a catalyst; a chemical agent that speeds up a reaction without being consmed by the reaction
every chemical reaction between molecules invovles both bond breaking and bond forming.
Changing one molecule to another generally involves contorting the starting molecule into a highly unstable state beforeth reaction can proceed.
the initial investment for starting a reaction; the energy required to contort the reactant molecules so the bonds can break; amount of energy needed to push the reactants over an energy barrier.
the energizing or activation is represented by the uphill portion of the graph; at the summit the reactants are in an unstable condition ; they are activated adn bonds are broken. (transition state); downhill park shows the los of free energy by the molecules
how is activation energy supplied?
in the form of heat that the molecules absorb from te surroundings
the bonds of the reactants break when?
when the molecules have absorbed enough energy to become unstable.
what does activation energy do as a barrier?
it creates a barrier that determines the rate of reaction; the reactants must absorb enough energy to reach the top of the activation energy barrier before the reaction an occur; in most cases, activation energy isso high and the transitional state is reach so rarely that reactions will hardly ever occr; it will only occur if heat is added; and although proteins, dna, and other complex molecules are rich in free energy; the barriers for selected reactions must occasionally be surmounted for cells to carry out the processes needed for life. ;
heat and reactions
heat speeds up reactions by allowing reactants to attain the transitional state more often.; but heat will also denature proteins and speed up all reactions, so the cell must use catalysis to speed up reactions
how does an enzyme work?
catalyzes a reaction by lowering the activation barrier, enabling the reactant molecules to absorb enough energy to reach the transitional state; they are very particular and determine what chemical processes will be going on in the cell at any particular time.
the reactant an enzyme acts on
when the enzyme binds to the reactant; while they are bound, the enzyme converts the substrate to the product of the reaction; ; very specific reactions
enzyme+substrate-->enzyme substrate complex-->enzyme+prouct
only a restricted region of the enzyme molecule actually binds to the substrat; it is typically a pocketor grove on the surface of teh prtein where catalysis occurs. ; usually formed by a only a few of the enzymes amino acids.
when the protein causes the enzyme to change its shape slightly. clasping handshake. brings chemical groups of theh active site into positions that enhance their ability to catalyze the chemical reactions.
specificity of an enzyme
attributed to a compatible fit between the shape of its active site and the shape of its substrate.; as a substrate enters teh active site, interactions between its chemical groups and those on the R groups of hte amino acids that form the active site of the protein cause the enzyme to change its shape slightly.
Exergonic reaction graph
lots of potential on top of the diving board (very unstable on top of it), then jumps off diving board increase the disorder of water (diffusion)
exergonic= delta G always negative, increase entropy, and generate some type of energy (heat etc)
Molecules with high potential energy
are unstable. and want to go to a stable area; the more free energy a system has-less stability and can do more work; more free energy a system has it has higher G (able to do more work) therefore it is less stable and this greater capacity that results and then entropy increases
low free energy, it uses energy to make a product high in energy; delta G >0; ; net gain of free energy, nonspontaneous; reactants are more stable; system always likes to stabilize itself.
Which one is spontaneous?
Describe the energy transformation that occurs when you climb to the top of the stairway?
you convert the chemical energy of food to the kinetic energy of your upward climb; at the top of the stairs, some of the energy has been stored as potential energy owing to your higher elevation; the rest is converted to heat. going down=kinetic energy