Lesson 3, Chapter 6 Flashcards
what is a chemical reaction
process in which one or more substances are changed into other substances
when do chemical reactions occur
when atoms combine with or dissociate from other atoms
chemical bonds are energy relationships that involve what
the electrons of reacting atoms
what is metabolism
sum total of all chemical reactions that occur within an organism
what are the 3 states of matter and how can they be changed
solid, liquid, gas; physically or chemically
what is energy
the ability to do work
how much mass does energy have and how much space does it take up
0
what is kinetic energy
energy is doing work
what is potential energy
energy is inactive or stored
what are the forms of energy
chemical, electrical, mechanical, radiant
what is thermodynamics
study of energy interconversions
what is the first law of thermodynamics
energy cannot be created or destroyed, but can be transformed from one type to another
what is the second law of thermodynamics
transfer of energy from one form to another increases the entropy of a system
what is total energy
usable + unusable energy
what determines the direction of chemical reactions
change in free energy
what is free energy
amount of energy available to do work
__ = G + ___
H = G + TS
What is gibbs free energy used to predict
whether a chemical process is sponteanous or not
what is a spontaneous reaction
may have to provide some activation energy but occurs without input of additional energy and will proceed naturally
what is a non spontaneous reactions
a continuous energy input is necessary for the reaction to proceed
what is the key factor to see if the reaction is sponteanous
deltaG is negative
whats the proper word for sponteanous reactions
exergonic
how do u tell if a reaction isn’t sponteanous
deltaG is positive
whats the proper word for sponteanous
endergonic
is the hydrolysis of atp exergonic or endergonic
exergonic
how can an endergonic reaction be coupled
to an exergonic reaction that the two reaction overall is thermodynamically favored
what is the major ‘energy’ molecule produced by metabolism
atp
what happens wherever a non-spon reaction needs to occur within the cell
atp is dispatched
what drives endergonic reactions
atp
what do cells use to drive reactions
atp hydrolysis
what happens to a phosphate during a couple reaction
from atp to glucose-phosphorylation
what do many proteins bind and use as a source of energy
atp
what is a catalyst
an agent that speeds up the rate of a chemical reaction without being consumed
what are the functions of enzymes
act as biological catalysts, increase the rate of chemical reactions, bind to substrates at an active site to catalyze reactions
main function of an enzyme
act as a catalyst
what can u use to recognize enzymes
-ase suffix
what is hydrolase
enzymes that facilitate the cleavage of bonds in molecules with the addition of the elements of water
what is activation energy
initial input of energy to start reaction
2 ways to overcome activation energy
large amounts of heat or using enzymes to lower activation energy
how do enzymes lower activation energy
bring reactants together so they don’t have to expand energy moving about until they collide at random
whats an active site
where a reaction takes place
whats a substrate
reactants that bind to active site
what is a enzyme substrate complex
formed when enzyme and substrate bind
what is affinity
degree of attraction between an enzyme and its substrate
what is saturation
plateau where nearly all active sites are occupied by substrate
what is michealis constant (Km)
substrate concentration where velocity is half maximal valur or half of the active sites are occupied at one time
what does a high Km enzyme need
higher substrate concentration
what are enzyme inhibitors
molecules that interact with enzymes in some way and reduce the rate of an enzyme-catalyzed reaction or prevent enzymes to work in a normal manner
what is competitive inhibition
inhibitor molecules binds to active site
what does a non competitive inhibition do
lower Vmax without affecting Km
where does the inhibitor bind
allosteric site
what are prosethetic groups
small molecules permanently attached to the enzyme and aids in enzyme function
what is a cofactor
usually inorganic ion that temporarilty binds to enzyme to promote a chemical reaction
what is a coenzyme
organic molecule that participates in reaction but is left unchanged afterward
are enzymes affects by environment
yes
what are enzymes usually affected by
temperature and pH
where do chemical reactions occur
metabolic pathways
which pathway syntehsizes cellular components
anabolic
which pathway breakdown cellular components
catabolic
how are proteins synthesized
bonding amino acids
what is a catabolic reaction
breakdown of reactants
what are catabolic reactions used for
recycling building blocks and for energy to drive endergonic reactions
what are the 2 ways to make atp
substrate level phosphorlyation and chemiomosis
what are electron carriers/shuttles
small organic molecules that play key roles in cellular respiration (for anabolic processes)
how are electrons shuttled
redox reactions
what is a redox reaction
nad+ and fad gain/lose electrons
what is oxidation
removal of electrons
what is reduction
addition of electrons
what ensures a cell synthesizes molecules when needed
anabolic pathways
what are the regulations of metabolic pathways
gene, cellular, biochemical
what is feedback inhibition and rate limiting step
product of pathway inhibits early steps to prevent over accumulation of product. can also alter a pathway by regulating the slowest step in the reaction (Rate limiting step)
what is proteasome
a large complex that breaks down proteins using protease enzymes
what is the role of ubiquitin
tags target proteins to the proteasome to be broken down and recycled
what does ubiquitin tagging allow the cell to do
degrade improperly folded proteins, rapidly degrade proteins to respond to changing cell conditions, recycle amino acids for new proteins
what do lysosomes contain
hydrolases to break down proteins, carbohydrates, nucleic acids and lipids
what is autophagy
recycling worn out organelles using an autophagosome
