intro to bioenergetics Flashcards
first law of thermodynamics
energy cannot be created or destroyed but only transforms from one form to another without being depleted
bioenergetics
flow and energy exchange within a living system
energy conversion example
photosynthesis
endergonic process
solar energy transferred to potential energy in carbohydrates, lipids and proteins
energy conversion example
cellular respiration
exergonic process
stored energy in plants couples to chemical compounds for biologic work
biologic work in humans
three forms
chemical- biosynthesis of cellular molecules
mechanical-muscle contraction
transport- transfer of substance among cells
types of reactions endergonic (endothermic)
energy requiring reaction
absorb heat or energy
ADP + Pi + energy = ATP
types of reactions exergonic (exothermic)
energy-yeilding reaction
release energy or heat
ATP = ADP + Pi + energy
metabolism
the Toal of all energy transformation that occur in the body
ATP
stored chemical energy that links the energy-yeilding (exergonic) and energy requiring (endergonic) functions within all cells
hydrolysis
digest or degrade complex carbohydrate, lipid and protien molecules into simpler forms the body absorbs and assimilates
-splits chemical bonds by adding H+ and OH- to the reaction
condensation
structural components of nutrients bind together to from more complex molecules and compounds
hydrolysis example
sucrose splits (using H2O) into glucose and fructose
dipeptide into 2 amino acids
condensation example
two glucose split (H2O is released) into maltose
2 amino acid into dipeptide
a reaction where energy is liberated
exergonic
a reaction where heat is absorbed
endergonic
formation of glycogen from glucose
endergonic
breakdown of ATP
exergonic
formation of proteins from amino acids
endergonic
oxidation and reduction
reactions transfer oxygen atoms, hydrogen atoms or electrons
types of reactions
oxidation (LEO)
result in loss of electrons
types of reactions
reduction (GER)
results in gain of electrons
if one substrate is losing electrons, the other is gaining and thus it is a _________ reaction
coupled
how to recognize enzymes
typically end with suffix are
ATP hydrolysis - ATPase
lactate hydrolysis - lactase
what are enzymes
specialized proteins
substrate
not consumed or altered
enzymes
what do they do
act as a biological catalysts
make a reaction more likely
how do enzymes work
interact with the reactants of a chemical reaction
reduce activation energy
enzyme kinetics
what happens to the rate of a chemical reaction as substrate concentration is increased?
rate will not be affected by the concentration
enzyme kinetics
what happens to the rate of a chemical reaction as enzyme concentration is increased
the reaction will occur at a faster rate
enzymes
lock and key mechanism
an enzyme combines with substrate to form and enzyme-substrate complex
converts to an enzyme-intermediate complex
converts to an enzyme product complex
disassociates into product + enzyme
enzyme in unchanged
enzymes ____________ by binding to the reactant molecules and bringing them into the best position to react with each other
lower the energy of activation
lock and key mechanism
enzyme-substrate interaction
enzymes turns on when its active site joins in a “perfect fit” with the substrates active site
ensures that the correct enzyme matches with its specific substrate to perform a particular function
co-enzymes
non-protein organic substances (iron, zinc, B-vitamins)
carrier job- intermediary products NAD+
activate otherwise dormant enzymes
assist the enzyme by binding substrate to the enzyme
modulators
a molecule that binds to an enzyme at a place other than the active site
regulates the enzyme activity by affecting the enzymes shape or configuration
allosterism: the fact that the modulator causes a change in shape of the enzyme
allosteric modulators can be postive or negative
positive modulator
active/stimulator
-increase activity of an enzyme
negative modulator
inhibitor
-decreases activity of an enzyme
oxidation
loss of electrons
transfer of
oxygen
hydrogen
electrons
reduction
gain of electrons (GER)
redox reactions
coupled reactions of oxidation and reduction, one substance losing electrons, the other gaining
measuring energy release
oxygen consumption is used to measure energy utilization in humans
oxygen is required for complete combustion of food
metabolism requires oxidation of food
the rate of metabolism is measured by determined the volume of oxygen consumed
max VO2
energy absorbing reaction
endergonic
energy releasing reaction
exergonic
chemical reaction where a substance is split into simpler compounds by the edition of water
hydrolysis
formation of more complex compounds from simpler compounds, water molecules released
condensation
addition of a phosphate (ADP+P= ATP)
phosphorylation
process by which cells transfer energy from food to ATP
cellular respiration
loss of electrons by a substance
oxidation
gain of electrons by a substance
reduction
coupled oxidation and reduction- one substance losing electrons the other gaining
redox
