Chapter 6 - Metabolism Flashcards
C-H bonds contain lots of what?
ENERGY
What is the breakdown of glucose for energy reaction? Balanced
C6H12O6 + 6O2 > 6CO2 + 6 H2O + ATP
What is the reaction for synthesis if glucose using light? What is this process called
Photosynthesis
6CO2 + 6H2O + light energy > C6H12O6 + 6O2
Photosynthesis uses light energy to produce temporary energy carrying Molecules called…
ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucelotide phosphate)
In photosynthesis what do those energy carrying molecules fix?
They fix carbon into sugars
Energy requiring pathways and energy producing pathways are called…
Energy require - anabolic
Energy producing - catabolic
Some organisms perform catabolism without oxygen, what is this process called?
Fermentation or anaerobic metabolism
in biosynthetic processes energy is needed from what molecules in plants and animals? In terms of anabolic and catabolic pathways
In animals - NADH
in plants - NADPH
Catabolic pathways breakdown glucose into how many ATP molecules per glucose?
36 usually but 36-38
Difference in kinetic vs potential energy?
Kinetic energy is energy of an object in motion
Potential is the energy an object contains that can be used once set in motion
Chemical bonds hold what type of energy?
Potential energy- once broken it’s kinetic energy
All energy transfers involve the loss of energy in unusable forms of heat called what?
Entropy
Entropy is a state of what?
Disorder, randomness, uncertainty
Gibbs free energy represents what?
The energy that is usable after entropy is accounted for
What is the equation for gibs free energy? What does each part mean?
Delta G = Delta H - T Delta S
Delta G - change in free energy for a chemical reaction
Delta H - energy change in reaction
T Delta S = energy lost as entropy in a reaction
Energy change in a reaction (Delta H) is also called what?
Enthalpy
Reactions that have a negative delta G means what?
The reactions release energy, meaning they have less free energy than the reactants (exergonic reaction)
Reactions that have a negative delta G and release energy are also known as…
Spontaneous reactions
Delta G that is positive means…
The reactants require energy input (endergonic reaction) means products have more free energy than the reactants
In terms of gonicity what is anabolic and catabolic?
Anabolic - endergonic
Catabolic - exergonic
What is activation energy?
Amount of Energy needed for a reaction to occur
Reactants activation energy is pretty high in cells, what can it be lowered by?
Catalysts or specifically enzynes
Difference between open and closed systems in terms of the laws of thermodynamics?
Open systems lose heat to its surroundings while closed systems do not
Main takeaways from the first law of thermodynamics
-amount of energy in universe is constant
-energy can’t be created or destroyed
Every energy transfer includes some amount of energy that is lost and is…
Unusable (energy is usually heat)
What is the definition of heat transfer in a system?
Energy transfer from one system to another that is NOT doing work
The measure of randomness and disorder in a system is called what?
Entropy
In terms of entropy a system with Low energy has how much entropy?
Relatively high amounts
Systems naturally proceed towards what direction in terms of entropy?
More entropy (disorder)
Does energy transfer decrease or increase the universes entropy?
Increase
When is ATP made?
Only when needed, can’t store ATP (extremely unstable molecule)
ATP is composed of an adenosine nucleotide, which is what chemically?
An adenine nucleotide + 5-carbon sugar (ribose)
ATP also has 3 phosphates bonded to the sugar, what are the arrangements and names of each phosphate group?
The phosphate group closest to the ribose sugar is alpha, then extending outwards is beta, then gamma.
Bond names between the phosphate groups?
Phosphoanhydride bonds - release lots of energy
Hydrolysis of what part of ATP releases a lot of energy, what molecule remains?
Hydrolysis of the beta-gamma bond on the phosphate groups releases lots of energy and a molecule called ADP, also an inorganic phosphate
Equation:
ATP + H2O > ADP + Pi + free energy
What is the delta G for ATP mole?
-14kcal/mol
In the sodium potassium pump what gives it the energy?
When ATP is hydrolyzed the gamma transfers into the transmembrane protein phosphorylating it (giving it energy)
Almost all enzymes are what macromolecule?
Proteins
What does an enzyme do physically to make an enzyme react more readily?
It functions by binding to the reactant and hold in a way that reacts more readily
What do enzymes lower?
The activation energy, they DO NOT change the reactions delta G
What gives the enzyme its specific properties?
The unique combination of amino acid R-groups (residues) of the active site
Lock and key often resembles…
The substrate and enzyme
What does induced fit mean?
It refers to the enzyme substrate interaction and how the structure of an enzyme and substrate change into an ideal arrangement
Enzymes may take part in substrates reaction by forming covalent bonds with substrates, BUT always…
Return back to original form (enzymes remain unchanged by the reactants they catalyze)
What is competitive inhibition?
A form of inhibition that occurs when an inhibitor molecule blocks substrates form binding to active site (basically molecule competes with substrate)
What is non competitive inhibition? What is it also called?
It’s also called allosteric inhibition, it is when a inhibitor molecule binds to the enzyme in a place different from active site and inhibits enzyme function
What are the 2 types of allosteric types?
Inhibition, and activation
What are coenzymes and cofactors?
Non protein helper molecules that are part of the enzyme, they promote optimal conformational
What are examples of cofactors and coenzymes?
Cofactors - inorganic ions, examples: Fe2+, Mg2+, Zn2+
Coenzymes - organic molecules - usually vitamins; examples: vitamins A,C, folic acid, E, B1,B2, B6, D2. They are supplied through the diet
What is feedback inhibition?
It is where a product of a metabolic pathway acts to regulate the pathway the product produced (self regulation)
Basically it inhibits its own pathway
Through glucose catabolism what is the allosteric inhibitor and activator of ATP?
ATP is its own allosteric inhibitor preventing the buildup of ATP while ADP is the allosteric activator triggering the production of ATP
