Metabollic Test Part 1
Metabolism
The many reactions occurring inside our cells are known as metabolism, metabolism is catabolism plus anabolism
catabolism
catabolism is when in a reaction bonds between reactants break down
anabolism
anabolism is when bonds between products form
activation energy
activation energy is the amount of energy needed to break the reactants bonds the change in this energy is called enthalpy
endothermic
energy is absorbed when reactants break which is endothermic
exothermic
energy is released when product bonds form which is exothermic
entropy
entropy is the randomness and disorder of objects, it is useless energy that cannot do work like heat
Gibbs free energy
Gibbs free energy is energy that is not lost and is still available to do useful work
exergonic
exergonic reactions release free energy
endergonic
endergonic reactions absorb free energy
The first law of thermodynamics
The first law of thermodynamics is the total amount of energy in the universe is constant, it cannot be created or destroyed but only converted from one form to another,
the second law of thermodynamics
the second law of thermodynamics is every energy transfer or transformation increases the entropy of the universe
Explain energy coupling
Energy coupling is the transfer of energy from one reaction to another in order to drive the second reaction, an exergonic reaction can be coupled to an endergonic reaction to provide free energy
hydrolysis of ATP
ATP + H20 = ADP + Pi + free energy hydrolysis
reverse dehydration synthesis reaction
dehydration synthesis ADP + P = ATP + water
reduction of NAD+
NAD+ + 2e + H+ = NADH
reduction of FAD
FAD + 2H + 2e = FADH2
Describe the main jobs of ATP
ATP drives all cellular reactions by providing the energy that is needed, its main jobs are chemical work which is when ATP supplies the energy that are needed to synthesize the macromolecules inside the cell, mechanical work to permit muscles to contract and chromosomes to move, and transport work to pump substances across the cell membrane active transport
Define substrate level phosphorylation and oxidative (chemiosmotic) phosphorylation
Substrate level phosphorylation does not occur across the membrane and is coupled with key exergonic reactions, it is the formation of ATP by the direct transfer of a phosphate group from a substrate to ADP, oxidative phosphorylation is the pumping of protons across the membrane which establishes an electrochemical gradient which provides the energy needed for phosphorylation, it is energy transferred indirectly from a series of redox reactions
Contrast aerobic and anaerobic
Aerobic cellular respiration requires oxygen, anaerobic respiration occurs in the absence of oxygen
Identify the mitochondrion structures and state their functions
The mitochondria is a round sausage shaped organelle that is scattered across the cytoplasm, the outer membrane smooth plays a similar role to the cell membrane, the inner membrane which has folds plays role in cellular respiration, it has protein and enzymes which attach to its inner surface to help with respiration, the matrix is the central fluid it is protein rich, intermembrane space is between two membranes, if the mitochondrion has a lot of cristae it has a greater surface area allowing for more places for reactions to occur and more places to catalyze reactions
Describe the main details of glycolysis
Glycolysis occurs in the cytosol and does not use oxygen, in the energy investment phase glucose and 2 atp are needed to start, the end result of the energy investment phase results in 2 glyceraldehyde- 3 phosphate and 2 ADP which is made from the help of phosphofructokinase, the second stage is the energy payoff stage where we start off from G3P and this occurs twice, 2NAD+ are needed, 4ADP and 2pi are needed, the end result of glycolysis is 2 pyruvate, 4ATP (net gain 2) and 2NADH, the atp is phosphorylated by substrate level phosphorylation
Explain the details of pyruvate oxidation
Pyruvate oxidation occurs in the mitochondrion matrix, the 2 pyruvates have to travel into the phospholipid bilayer using transport proteins, this cycle needs oxygen, there is a decarboxylation reaction and a dehydrogenation reaction and CO2 is released, NADH+ is also created, the loss of carbon creates acetyl and the acetyl combines with S in coenzyme A resulting in the creation of acetyl – COA, the reaction needs 2 pyruvate, 2NAD+ and 2COA to create 2 Acetyl COA, 2NADH, and 2CO2
Discuss the main details of citric acid cycle
The citric acid cycle occurs in the mitochondria matrix, and it needs oxygen, the process occurs twice, the acetyl group joins with oxaloacetate to form citric acid, the citric acid goes through a series of reactions losing 2CO2 molecules along the way, NAD+ and FAD are coenzymes that join with electrons and Hs to form NADH and FADH2, ADP gets phosphorylated by substrate level phosphorylation to form ATP, the oxaloacetate cycles around again to pick another acetyl group, the total results are 4CO2, oxaloacetate, 6NADH, 2FADH and 2ATP
Describe the electron transport chain
The electron transport chain occurs in the inner mitochondrial membrane, it requires oxygen, NADH is able to produce 3 ATP and FADH is able to produce 2 ATP, NADH arrives at the NADH dehydrogenase, it donates its protons and electrons which creates enough energy to throw a proton to the intermembrane space, electrons then move to ubiquinone because it is more electronegative and it’s a coenzyme basically a taxi that brings electrons to the second protein, the energy throws another proton to the intermembrane space, It then goes to the next protein and does the same thing, oxygen is the final proton acceptor, it combines with the protons in the matrix to create water
describe oxidative (chemiosmotic) phosphorylation
Since the hydrogen protons have begun to gather in the intermembrane space there is a creation of a concentration gradient and an electric potential gradient, the protons then travel through ATP synthase which is a transport protein and move back to the other side of the membrane, this form is known as the proton motive force, this process provides enough energy to phosphorylate ADP + P into ATP, this is oxidative phosphorylation and is called chemiosmosis, FADH also follows the same path but starts at ubiquinone which means it can only make 2ATP
Explain where each ATP is formed and where all of the carbons are released
4 ATP (net gain 2) is formed from glycolysis and 2ATP from the citric acid cycle, the NADH and FADH goes to the ETC to make even more ATP, 2 carbons are released in pyruvate oxidation and 4 carbons are released in the citric acid cycle, so all of the energy from glucose is completely gone by the end of the citric acid cycle