Cellular metabolism Flashcards
what is the equation for cellular respiration
C6H12+O6–>6CO2 +6H20
reaction is ______
bidirectional
A+B (goes back and forth) C+D
what is a catabolic reaction
breakdown of larger molecules into smaller molecules; releases energy
what is anabolic reaction
production of larger molecules from smaller reactant; required energy
what is the first law of thermodynamics
energy cannot be destroyed or created, transformed
what is the second law of thermodynamics
with every transfer or transformation of energy, some useable energy is release
what is an endergonic reaction?
chemical reactions that require an input of energy; products contain more free energy than the reactants.
energetically uphill
what happens in an endergonic reaction?
the products have more energy than the reactants
what is an exergonic reaction?
chemical reactions that release energy.
products will have less free energy than the reactants.
energetically downhill
what happens in an exergonic reaction
the reactants have more energy than the products
how do endergonic reactions in physiology occur? explain with an example
energy from the environment is brought down in exergonic reactions to drive the endergonic reactions in our bodies
your cellphone battery releases energy because of the reactions occurring inside of it. if yo put your battery inside of your cell phone then it can be used to power your phone
what is activation energy
the energy required for the reactants to engage in a reaction
most molecules lack the activivation energy needed for a reaction to occur
what can activation energy take the form of?
heat
what is an enzyme
a class of proteins that serve as a biological catalysts(catalysts are chemicals that increase rate of reaction, are not changed by the reaction, have no effect on free energy of reactants or products, in enzymatic reactants or products, in enzymatic reactions, reactants are called substrates)
what are catalysts
catalysts are chemicals that increase rate of reaction, are not changed by the reaction, have no effect on free energy of reactants or products, in enzymatic reactants or products, in enzymatic reactions, reactants are called substrates
what is a ligand
receptor interactions
anything that binds to a receptor
what is a receptor
a protein
what is specificity based on?
shape
what does it mean that specificity is only based on shape
the substrate and the enzyme must fit together like a lock and key
how are enzymes named
function of enzyme + suffix -ase
how is enzyme activity measured?
measured by the rate at which substrate is converted to product
how is enzyme activity influnced
concentration of enzyme and substrate
enzyme-subrate affinity
temperature
pH
regulation oby modulators
covalent regulation
feedback inhibition
feedforward activation
how do we speed up reactions?
add more enzymes
regardless of the enzyme concentration, there will be a ________ ________
maximum rate
Once all ______ are bound to _____, adding more _____ will not _____ _____ the reaction
enzyme, substrate, substrate, speed up
when does affinity matter
low substrate concentrations
what happens to the reactions when temp increases
an increase in temp will increase the rate of reactions until the temperature reaches a few degrees above body temp (at that point the enzyme is denatured)
when do enzymes exhibit peak activity
within narrow pH range
what are metabolic pathways
most reactions are linked together in a chain (or web)
These begin with an initial substrate and end with a final product with many enzymatic steps along the way
what is feedback innhibition
If C starts to accumulate too much in the cell, it can inhibit enzyme 2 and stop its own production
what is end product inhibition
some metabolic pathways have more than one possible end product
what is ATP
the medium of energy exchange
it powers a lot of endergonic reactins in our cells
what happens when water is added to ATP
a phosphate group gets removed and this reaction is VERY exergonic (ATOP + (h20)–> ADP +P1)
food is brokwn down during cellular respiriation. where does that energy go
the engery is released to make ATP
what is ATP broken down into?
it provides energy for such endergonic reaction as: cellular movement, sythesis, and active transport
what is ATP broken down into?
it provides energy for such endergonic reaction as: cellular movement, sythesis, and active transport
what are the 4 stages of cellular respiration
Glycolysis
Linking step
Krebs cycle
Oxidative phosphorylation
what is glycolysis
this is the first step in catabolism of glucose
occurs in the cytoplasm of the cell and does not require oxygen
for every molecule of glucose, 2 pyruvate created, 2 ATP’s consumed, 4 ATPs created, net 2 ATP, 2 NAD+
where does glycolysis take place
the cytoplasm
which cycle of cellular respiration does not require oxygen
glycosis
what is the input of glycolysis
glucose
what is the output of glycolysis
2 pyruvates, which move on to the Bridge Reaction / Linking Step
2 NADH, which move to the electron transport chain in step 4
2 net ATPs, which are used for energy somewhere else in the cell
where does the bridge/linking step take place
mitochondrial matrix
which steps of cellular respiration require oxygen
linking/bridge, krebs, oxidative phosphorylation/electron transport chain
what is the input of the bridge/linking step?
2 pyruvates
what is the output of the bridge/linking step
2 acetyl coA molecules, which move on to the Krebs Cycle
2 NADH, which move to the electron transport chain in step 4
where does the krebs cycle take place
mitochondrial matrix
what is the input of the krebs cycle
2 acetyl coA molecules
what is the output of the krebs cycle
(after two turns of the cycle)
6 NADH, 2 FADH2, which all move on to step 4 electron transport chain
2 ATPs, which are used immediately for energy somewhere else in the cell
where does the oxidative phosphorylation/electron transport chain take place?
inner mitochondrial membrane
what is the input of oxidative phosphorylation/election transport chain
Electrons from all NADH and FADH2 were collected during steps 1-3
what is the output of oxidative phosphorylation/electron transport chain?
~34 ATPs
