Adriana Cardenas. M (Ch.8) (8.1 An organism's metabolism transforms…
Adriana Cardenas. M (Ch.8)
8.1 An organism's metabolism transforms matter and energy, subject to the laws of thermodynamics.
-- total energy of an organism's chemical reactions.
-- release energy by breaking down complex molecules.
Ex; Cellular respiration
-- to consume energy to build complex molecules form simple ones.
Ex; simple molecule = amino acids
amino acids = protein
-- average kinetic energy in a body or matter regardless of volume.
Temperature involves a single body while heat involves transfer of thermal energy.
-- the theory that states that all particles move all the time.
Solidi-- molecules vibrate and stay in one area.
Liquid-- particles are moving but sill touching each other.
Gas-- particles are far apart and move randomly.
-- absorbs fee energy, ΔG is positive.
-- releases free energy, ΔG is negative.
-- absolves thermal energy.
-- gives off thermal energy.
-- the energy of motion, of mater that is moving.
-- the capacity of matter to cause change as a consequence of its location or arrangement.
Food have potential energy which is available for relate in chemical reaction.
Energy is measured in
Energy is released by
-- braking down complex molecules to simpler compounds.
If the foods energy is negative then it takes more energy to be digested within if it has zero energy it takes no energy.
Food gets it energy by the food change.
First law of thermodynamics
-- Energy is not created or destroyed. It can only changes form potential energy to kinetic energy to heat energy.
Second law of thermodynamics
--the entropy of the universe is always increasing.
8.2 The free-energy change of reaction tells us whether or not the reaction occurs spontaneously.
-- Energy that can perform work when temperature and pressure are uniform throughout the system.
The amount of energy consume, that is available to do useful work.
Gibbs Free Energy equation---> ΔG = ΔH – TΔS
total energy of a system / order.
measure of disorder (always increasing, how energy is destructive in a system.
absolute temp.(Kelvin units = °C + 273)
= Free energy /
A negative ΔG = Spontaneous ----->Photosynthesis
A positive ΔG = Non-spontaneous --> Cellular Respiration
ΔG = 0 Equilibrium
If the entropy increases the free energy decreases.
If the entropy decreases the free energy increases.
If the enthalpy increases then the free energy increases.
If enthalpy decreases than the free energy decreases.
A + B → AB
Endergoinc (absorbs energy)
ΔG > 0 positive
Biological ex; Photosynthesis
Equation ; Light+ 6CO2 + 6H2O → C6H12O6 + 6O2
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AB → A + B
Exergonic (releases energy)
ΔG < 0 Negative
Biological ex; Cellular Respiration
Equation ; C6H12O6 +O2→CO2+H2O+energy
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8.3 ATP powers cellular work by coupling exergonic reactions to endergonic reactions.
ATP is made of
An adenine ring
A ribosem sugar
3 phosphate groups
The hydrolysis of ATP
-- The catabolic reaction process by which chemical energy that has been stored in high energy phosphorylation bonds in adenine triphosphate is released by splitting these bonds.
When ATP is hydrolyzed ADP is combined with a phosphate to form ATP.
-- transfer /chemical process that involves the addition of phosphate of an compound.
After hydrolyzed ATP become ADP
ATP is recharged by adding another ATP
ATP can be used to perform
-- building large molecules such as proteins
-- muscle contraction
-- Pumping solutes such as ions across a cellular membrane.
Ex; Provides energy for the dehydration synthesis reaction that liars amino acids together.
8.4 Enzymes speed up metabolic reaction by lowering energy barriers.
An enzyme is a macroeconomic called catalyst.
speed up reactions w / o being consume buy it.
Without enzymes there would be chemical ration "traffic jams" cause they would tack forever.
they often named
Most enzymes end in -ase ( lactase, sucrase..)
Enzymes can recognize their specific substance bc. they have specific amino acid sequences and shapes that allow them to have recognition ability.
-- the area of the enzyme that ACTUALLY binds to the substrate
It's a pocket of the surface of the enzyme where catalysis occurs.
The whole enzyme doesn't bind only part of it.
-- What the enzyme acts on. ( like a puzzle piece t the enzyme)
-- when the enzyme is bonded to the substrate. (the enzyme and substrate are put together)
Enzymes only affect certain reaction b/c they're able to recognize it specific substrate (sucrose & surcease)
Temp. and pH can affect how enzymes function.
-- up to a point, as temperature increases the rate of enzyme activity increase this is b/c substrates are colliding with active sites a lot.
if it gets too high then the enzyme activity drops by a lot b/c the heat messes with the hydrogen / ionic bonds that help stabilize the enzyme.
All enzymes have an optimal temp. where their reaction rate is the highest.
Most human enzymes optimal temp. is b/w 35- 40 C degrees
( body temp.)
With out an enzyme it requires more energy to a reaction to happen.
On the product ΔG does not changes by the presence of enzymes, but the activation energy does.
In order for the hydrolysis of sucrose to speed up it needs to use an external help sucrose.
-- energy that must be absorbed by reactants to reach the unstable transition state, in which bonds are likely to break, and from which the reaction can proceed.
8.5 Regulation of enzymes activity helps control metabolism.
Cofactors & Coenzymes are activators for enzymes. Allows the enzymes to function, basically turning the enzyme on.
-- blocks the substrate form entering an active site
-- binds to another part of the enzyme, thus changing the enzyme shape.
-- molecules may inhabit or activity when they bind to a site separate from the active site.
-- the binding of a substrate molecule to one active site in a multisubunit enzyme changes the shape of all sub-units such that their active sites are stabilized in the active form.
-- the end product of a metabolic pathway acts as an inhibitor of an enzyme within the pathway.
Sarin gas and DDT are inreverential enzyme inhibitors for important enzymes found in the nervous system.