Exam 3 Metabolism Flashcards
the total chemical reactions of an organism
metabolism
arises from the interactions between molecules within the orderly environment of a cell
metabolism
Define metabolism
the total chemical reactions of an organism
Metabolism arises from
the interactions between molecules within the orderly environment of a cell
What are metabolic pathway
metabolic pathways are a series of linked chemical reactions
How is each step in a metabolic pathway catalyzed
by a specific enzyme for example molecule A would be enzyme 1 and so on
Describe the how the molecules are produced in metabolic pathways
the molecules produced by one retain is the starting point of the next reaction for example A would be the starting molecule enzyme 1 and reaction 1 then B would be enzyme 2 and the 2nd reaction etc.
series of chemical reaction where the substrate of a reaction is the product of the previous reaction. Each reaction is catalyzed by a different enzyme
metabolic pathways
name two types of metabolic pathways
catabolic and anabolic
describe catabolic pathways
breaks down molecules making them more simple and produces energy….
describe anabolic pathways
builds up molecules or makes them more complicated and requires extra energy
breaks down complicated molecules into simpler ones and energy is stored in the molecule becomes available to do work in the cell
catabolic pathways
builds up complicated molecules becomes available to do work in the cell and energy is consumed to build up these complex molecules
anabolic pathways
What is energy?
light, heat, movement, electricty, etc
what is potential energy
energy that is stored in matter based on position and structure
what is chemical energy
potential energy based on the chemical bonds of a molecule
energy that matter possesses because of its location or structure
potential energy
potential energy available for release in a chemical reaction
chemical energy
C6H12O6 vs CO2
chemical energy
different molecules have different bonds, so they have different amounts of chemical energy
chemical energy
molecules have chemical energy in their bonds
chemical energy
what is the equation for free energy
ºG (products) -G (reactants) =
-
reactants that release energy
+
reactions that release energy
Explain how potential energy converts to kinetic energy
a diver has more potential energy on the platform than in water, diving converts potential energy to kinetic energy
Explain how kinetic energy converts to potential energy
climbing up converts the kinetic energy of muscle movement to potential energy, a diver has less potential energy in the water than on the platform
the energy in a particular molecule has sometimes abbreviated
G (free energy)
represents difference in the amount of energy between the final state and the initial state
free energy ∆G
∆G =
G final state -G initial state
if ∆G is negative
the reaction will release energy ( this reaction will tend to be spontaneous
If ∆ G is positive
the reaction will require the input of energy
More free energy is
higher G, less stable, and greater work capacity
in a spontaneous change
the free energy of the system decreases ( ∆G <0), the system becomes more stable, the released free energy can be harnessed to do work
less free energy
lower G, more stable, less work capacity
proteins are
polymers of amino acids
name catalyze chemical reactions
free energy and activation energy
free energy is not
affected by enzymes
activation energy are
lowered by enzymes
proteins that catalyze chemical reactions
enzymes
what does catalysts do in metabolic reactions
catalysts speed up metabolic reactions by lowering activation energy
enzymes bind to
one or more substrates and confer them to one or more products
enzymes are unchanged
at the end of the chemical reaction
are usually named with the suffix “-ase”
enzymes
how do enzymes work - active site
pocket that binds to the substrate, based on shape of enzyme and substrate
how do enzymes work - specifically
Each specific enzyme binds to specific substrate and catalyzes on a specific reaction
how do enzymes work - lock and key and induced fit
each enzyme matches a substrate like a lock a key and binding to the substrate causes the enzyme to fit better
describe enzyme action
enzyme + substrate ➡️ enzyme-substrate complex ⬇️
stabilizes transition state ➡️ enzyme-product complex⬇️
enzyme + product
describe in detail enzyme action in six steps
- substrates enter active site, enzyme changes shape that is its active site enfolds the substrate (induced fit)
- substrate held in active site by interactions, such as hydrogen bonds and ionic bonds
- active site can lower EA (activation energy) and speed up a reaction.
- substrates are converted to products
- products are released
- active site is available for two new substrates molecules
Give an example of a reaction written in a formula
Substrate Catalase Product
⬇️ ➡️ I
2H2O2 2H2O2 + 02
what changes enzyme activity?
enzyme activity depends on shape of enzyme and shape of substrate
Define denaturation
unfolding of the enzyme- changes in shape
denaturation in temperature
high temperature can break H-bold
denaturation in pH
changes ionization of side chains, breaks ionic bonds
what are inhibitors (control of enzymes)
molecules that turn off enzymes
what are competitive inhibitors
binds to active site blocks substrate binding
what are noncompetitive inhibitions
binds to a different site, pulls on protein chain, changes the shape of the active site
-the end product of a pathway inhibits the first enzyme in the pathway
feedback inhibition 1st
-shuts down the pathway if the cell is not using the end product
feedback inhibition 2nd
-the pathway will turn on again if the cell starts using the end product
feedback inhibition 3rd
- the end product of a pathway inhibits the first enzyme in the pathway
- shuts down the pathway if the cell is not using the end product
- the pathway will turn on again if the cell starts using the end product
feedback inhibition
name two enzyme names
catalase and DNA Polymerase
what is another name for oxidation-reduction reactions
Redox
define oxidation-reduction reactions
chemical reactions where one or more electrons are transferred from molecule to another
define oxidation
chemical reaction where molecules looses an element
define reduction
chemical reactions here a molecule gains an electron
what does the acronym OILRIG stand for oxidation-reduction reactions
Oxidation Is Loss Reduction is Gained
In oxidation electrons
lose
In oxidation hydrogen
sometimes lose
In oxidation oxygen`
sometimes gain
in oxidation energy (organic molecules in the cell)
gives the cell energy (catabolism)
In reduction electrons
gain
in reduction hydrogen
sometimes gain
in reduction oxygen
sometimes lose
in reduction energy (organ molecules in the cell)
require energy from the cell (anabolism)
What is the function of ATP
it is used to store chemical energy readily available
What are the forms of ATP
- ATP “charged” form - 3 phosphates
- ADP “ dead” form - 2 phosphates
- AMP “dead” form - 1 phosphate
What does adenosine triphosphate stand for
ATP
how is ADP converted to ATP
substrate-level phosphorylation and oxidative phosphorylation
how is ADP converted to ATP by substrate-level phosphorylation
a phosphate molecule + ADP —–> molecule + A
how is ADP converted to ATP by oxidative phosphorylation
membrane and lots of hydrogen ions plus few ions ATP synthesis protein —-ADP + P turns to ATP
what is the function of electron carriers
picks up electrons from a molecule and drops them off somewhere else and it carries two electrons
what are the types of electron carriers
- NAD+ (electrons lacking)/ NADH (has electrons) - cellular respiration and fermentation– catabolic reactions
- FAD/FADH2- cellular respiration
- NADP+/NADPH- photosynthesis —anabolic reactions
Energy stored in molecules becomes and is related to
Available to do work… Is related to catabolic pathways
Is energy that matter possesses because of its location or structure
Potential energy
Is potential energy ready for release in a chemical reaction
Chemical energy
Molecules have________ in their bonds
Chemical energy
Different molecules have different ________, so they have different amounts of
Bonds, chemical energy
The energy of a particular molecule has is sometimes abbreviated as G
Free energy
Represents difference in the amount of energy between the final state and initial state
Free energy
What happens when free energy is negative
The reaction will release and will tend to be spontaneous
What happens when free energy is positive
Reaction will require the input of energy
Proteins that catalyzed chemical reactions
Enzymes
Catalyst speed up metabolic reactions by
Lowering activation energy
Binds to one or more substrates
Enzymes
enzymes bind to one or more substrates and
Convert them to one or more products
What happens to the enzymes at the end of chemical reaction
They are unchanged
The reactants form a ________ on their way to forming the products.
Transition state in Activation energy
____________to form the transition state, even if the _______ of the entire reaction is negative
It takes energy…… Free energy…. In activation energy
The energy needed to for the transition state is called
activation energy
In activation energy, in order for the reaction to proceed there must be
an initial investment of energy equal to the activation energy
enzymes lower the Ea of a reaction but
do not affect the free energy of the reaction
enzymes are not_________ during what reaction
permanently altered during the reaction (activation energy)
How do enzymes lower activation energy?
by specifically binding to the substrate(s)
the substrate is the reactant that the enzyme acts upon
together they form an enzyme-substrate complex
After enzymes form an enzyme-substrate complex while lowering activation energy what action is performed next
While the enzyme and substrate are joined;
- the catalytic action of the enzyme converts the substrate to the products of the reaction
- the reaction catalyzed by the enzyme is very specific and is based on the shape and chemical properties of the enzyme and the substrate
The region of the enzyme where the substrate binding occurs is called
the active site ( this happens in the process of enzymes lowering activation energy)
The active site is usually
a small part of the protein
The active site shape specifically
matches the substrate shape (like a lock and key)
When enzymes are lowering activation energy, their are interactions between the active site and the substrate what does this cause
It causes the protein to change shape slightly, so that the active site fits even more snugly around the substrate and this is referred to as induced fit similar to a clasping handshake
