Chapter 8 (Enzymes and ATP) Flashcards
What does energy come in as in an ecosystem?
light
What does energy turn into in an ecosystem?
heat
What is chemical energy?
cellular work
What is cellular work?
how a cell functions with energy
What is metabolism?
the totality of an organism’s chemical reactions and molecular transformation happening within a cell
What does metabolism allow for?
interactions that transform matter and energy
What does a metabolic pathway start with?
reactants
What does a metabolic pathway end with?
products
What are the types of metabolic pathways?
catabolic and anabolic
What are catabolic pathways?
take molecules and break them down (like glycolysis)
What are anabolic pathways?
synthesis pathway that builds molecule WITHIN the context of the cell (like citric acid cycle and oxidative phosphorylation)
What are the two forms that free energy comes in during a metabolic reaction?
exergonic and endergonic
What is an exergonic reaction?
release of free energy and they liberate the energy within the cell
Describe the process of an exergonic reaction.
2 molecules with a lot of energy make a compound and release some stored chemical energy from the reactants
LOOK AT THE EXERGONIC GRAPH
______
What is the peak on an exergonic graph represent?
activation energy
Are exergonic reactions spontaneous or non-spontaneous?
spontaneous
What is an endergonic reaction?
absorption of free energy
Describe the process of an endergonic reaction.
2 or more reactions (molecules) that have little energy, absorb energy and that forces them to interact
Are endergonic reactions spontaneous or non-spontaneous?
non-spontaneous
What is the Gibbs free energy for equilibrium equation?
delta G = delta H - T x delta S
What does delta G represent in the Gibbs free energy for equilibrium equation?
change in free energy
What does delta H represent in the free energy for equilibrium equation?
change in enthalpy
What does delta S represent in the free energy for equilibrium equation?
change in entropy
What does T represent in the free energy for equilibrium equation?
temperature in Kelvin
What does the cell use for energy?
ATP
What is the full name for ATP?
adenosine triphosphate
What is the structure of ATP?
nitrogenous base (adenine) sugar ring (ribose) 3 phosphate groups
Where is energy stored within ATP?
in the phosphate groups since the negative oxygens don’t like being next to one another
What is energy coupling?
reactions that give up energy and uses that given off free energy to start the next reaction
Overall, what free energy reaction is energy coupling?
exergonic
How does ATP break down?
hydrolysis
ATP has “high/low” energy bonds aka chemical structure
ATP has “high” energy bonds (-7.3 kcal/mol)
ATP is renewable/non-renewable within a cell via exergonic/endergonic reaction
ATP is renewable within a cell via endergonic reactions because energy can be stored as well
What ending do enzymes have?
-ase
What are enzymes also referred to as
catalysts
What do enzymes do?
break bonds and reform bonds
Can enzymes be used multiple times?
yes
What are enzymes primarily used for?
speed up reactions, to change the energy state in a chemical reaction
What is activation energy?
initial energy investment needed to start a chemical reaction
What do enzymes do to the activation energy (Ea)?
lower activation energy for a reaction to start
What are substrates?
enzyme reactants, they attach on to the enzyme
What is the active site?
what the substrates bind to
What is an enzyme-substrate complex?
when the enzyme and substrate bind
What kind of macromolecule are enzymes?
protein
What factors affect proteins?
temperature and PH affect enzymes, amount of substrate and enzymes available
If an enzyme is affected by pH or temperature, what happens?
can lead to denaturation (tertiary level of protein structure is unwound, though the backbone is still intact)
What are the types of cofactors?
coenzymes (organic) and inorganic ones
What are cofactors?
nonprotein enzyme helpers that help the enzyme work more efficiently
What are some examples of coenzymes aka organic cofactors?
vitamins like vitamin B
What are some examples of inorganic cofactors?
ions like Fe+
What are the types of inhibitors?
competitive and non-competitive
What is a competitive inhibitor?
binds to an active site (mimics a substrate) even though they only LOOK like substrates and they compete with substrates to bind to the active site
What is a non-competitive inhibitor?
binds to a different location that is NOT the active site to not allow the enzyme to work efficiently by changing the shape of the active site
When something binds to a protein what happens to the shape of the protein?
it changes shape
Where do regulatory molecules come from?
inside the cell
What type of regulation is used within the cell?
allosteric regulation
What is allosteric regulation?
organic molecules FROM INSIDE THE CELL that binds to an allosteric site
What is cooperativity (like allosteric activation) ?
includes multi subunit enzymes, the binding stabilizes the rest of the subunits for favorable changes via amplification
What is allosteric inhibition used for?
the allosteric inhibitor binds to an allosteric site on an enzyme to prevent form overproducing too much of a molecule
What delta G number is exergonic reactions?
negative numbers
What is the law of thermodynamics?
energy of the universe is constant (can’t create or destroy it)
energy transfers/transforms increase entropy
What is entropy?
the measure of randomness, disorder that applies to diffusion
What is energy flow?
come from somewhere, go to somewhere
What type of systems are organisms?
organisms are open systems, meaning they are acceptors of energy and raw materials
To create ordered structures is what metabolic pathway?
anabolic
To increase entropy is what metabolic pathway?
catabolic
What is a metabolic pathway?
series of enzymes transforming starting molecule and energy in multiple steps
In what energy form does the cell send energy out of the system?
thermal energy aka heat
In an exergonic reaction, is delta G negative or positive?
negative
What is the structure of RNA?
1 adenine nitrogenous base
1 ribose
1 phosphate group
What do exergonic reactions utilize to give off the extra energy within a cell?
ATP
To make ATP be renewable again, what energy reaction takes place?
endergonic (absorption)
What is a catalyst?
a chemical agent that speeds up a reaction without being destroyed/consumed in the reaction
Are enzymes specific or non-specific to substrates?
specific substrates needed for the enzyme to work
Are the active sites of enzymes flexible regions?
when substrates bind to the active site, the shape of the enzyme changes aka make an induced fit
What is the ideal temperature for enzymes in our body?
35 to 40 degrees Celcius
What is the ideal pH for enzymes in our body?
6 - 8 pH
What are some ways enzymes help lower the energy barrier aka activation energy?
orienting substrates correctly
straining substrate bonds
providing a favorable microenvironment (like pH)
participation in substrate reactions
Where do competitive inhibitors bind to?
fights to bind to an active site (mimics a substrate) even
Where do inhibitors GENERALLY come from?
the external environment, like drugs/toxins
What are regulatory molecules?
enzyme inhibitors from inside the cell
Are enzymes just one protein or multi subunit proteins?
enzymes are multi subunit proteins that work together
Where do regulatory molecules bind to?
the space in between the subunits of proteins (aka the quaternary structure)
oo ------> o
oo
What is the space in-between the subunits of proteins called?
allosteric site
What is feedback inhibition?
a product of a metabolic pathway that shut downs the pathway
What does feedback inhibition prevent?
prevents cell from wasting chemical resources
What does the first law of thermodynamics state?
energy is conserved
What does the second law of thermodynamics state?
every energy transfer increases the randomness (entropy) in the universe
Are cofactors proteins?
no
