Biological Order And Energy Flashcards
energy
the capacity to do work or cause change
work
a force acting on an object over a distance
chemical reaction
bond rearrangements
first law of thermodynamics
energy is neither created nor destroyed, only transferred
entropy
a measure of chaos/disorder
kinetic energy
energy of motion
thermal energy
a subset of kinetic energy concerned with the energy of atoms/molecules in random motion
potential energy
energy that is stored due to something such as position or composition
chemical energy
energy stored within chemical bonds, released when bonds are broken
gibbs free energy
energy that is able to do work, decreases as entropy increases
endergonic
non-spontaneous, requires energy input
exergonic
spontaneous, releases energy
2nd law of thermodynamics
every transfer or transformation of energy increases the entropy of the universe
spontaneous
proceeds without the need for invested energy
catabolic
breaking complex molecules into smaller subunits, releases energy, -ive delta G (increases entropy of the universe)
anabolic
building complex molecules, requires energy investment, +ive delta G (decreases entropy of the universe)
redox reaction
chemical reactions in which electrons are transferred from one reactant to another
reduction
gain of electrons
oxidation
loss of electrons
electron shuttle molecule
cofactor for redox reactions
- transfer electrons from a redox reaction to an ETC
- ex NAD+, FAD, NADP+ (oxidized form)
- are at their highest energy state form reduced
electron transport chain
a series of increasingly electronegative membrane proteins that pass along electrons, releasing usable energy in a stepwise manner
energy coupling
energy released from exergonic reactions is used to power endergonic reactions
metabolic pathway
all the chemical reactions involved in converting a starting material to a product, each step being catalyzed by a different enzyme
metabolic
the sum of all chemical reactions that happen inside a cell
substrate-level phosphorylation
kinase (enzyme) removes a phosphate from a high energy substrate and attaches it to ADP to regenerate ATP
competitive inhibition
when an inhibitor competes with the substrate by binding to the active site of an enzyme; can be overcome by increasing the concentration of substrate
non-competitive inhibition
an inhibitor binds to an allosteric site (region on an enzyme other than the active site), causing the enzyme to change shape and become ineffective; cannot be overcome by increasing the concentration of substrate
cofactor/coenzyme
metal ions (inorganic materials)/organic molecules (vitamins) that are required for catalytic activity of enzymes
phototroph
obtain energy from light
chemotroph
obtain energy from organic and inorganic chemicals
autotroph
use inorganic carbon (CO2) to build macromolecules from scratch
heterotroph
absorb organic molecules (sugars) from the environment and adapt them
substrate-level phosphorylation
kinase (enzyme) removes a phosphate from a high energy substrate and attaches it to ADP to regenerate ATP
chemiosmosis
movement of ions down an electrochemical gradient
