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Energy, Enzymes, and Metabolism - Coggle Diagram
Energy, Enzymes, and Metabolism
Enzyme and Ribozymes
Ribozymes
RNA molecules with catalytic properties
Activation energy
Initial input of energy to start reaction
Enzymes
Protein catalysts in living cell
How enzymes lower activation energy?
Straining bonds in reactants to make it easier to achieve
transition state
Positioning reactants together to facilitate bonding
Changing local environment
Catalyst
Agent that speeds up the rate of chemical reaction without being
consumed
Enzyme terminology
Substrate
Enzyme-substrate complex
Active site
Substrate binding
interaction also involves conformational changes
enzyme have a high specificity for their substrate
Enzyme Reactions
Saturation
all active sites are occupied by substrate
all active sites are occupied by substrate
Vmax = velocity of reaction near maximal rate
Michaelis constant (Km)
Substrate concentration where velocity is half maximal value
High KM enzyme needs higher substrate concentration
Inhibition
non-Competitive inhibition
Inhibitor binds to allosteric site, not active site
Lowers Vmax without affecting Km
Competitive inhibition
Inhibits ability of substrate to bind
Km increases
Molecule binds to active site
Enzymes requirement
Prosthetic groups – small molecules permanently attached to the
enzyme
Cofactor – usually inorganic ion that temporarily binds to enzyme
Coenzyme – organic molecule that participates in reaction but is
left unchanged afterward
Energy and Chemical Reactions
Kinetic Energy ( associated with movement)
Potential Energy (structure or location)
Chemical energy ( molecular bonds)
Laws of Thermodynamics
1st Law
energy cannot be created or destroyed but can transformed from
one type to another
2nd Law
The transfer of energy increases the entropy
Total energy= Usable energy + Unusable energy
Free energy (G)= amount of energy available to do work
delta G = delta H - T x delta S
change in G= Positive ( endergonic, not spontaneous, energy
absorbed)
(H)= enthalpy, (S)= entropy, (T)= temperature in Kalvin
change in G= negative (exergonic, spontaneous, energy
released)
ATP
Synthesis
endergonic
the energy comes from the hydolysis energy
Hydrolysis
energy liberated to drive cellular processes
exergonic
Formation of product
Recycling of organic molecules
Proteasome
Proteases cleave bonds between amino acids
Ubiquitin tags target proteins to the proteasome to be broken
down and recycled
large complex that breaks down proteins using protease
enzymes
Lysosomes
hydrolases to break down proteins, carbohydrates, nucleic acids,
and lipids
Autophagy – recycling worn out organelles using an
autophagosome
mRNA degradation
Exosome
Multiprotein complex uses exonucleases
Exonucleases
enzymes cleave off nucleotides from end
Metabolism
Regulation of metabolic reactions
Gene regulation
Biochemical regulation
Cellular regulation
Catabolic Reaction
Breakdown cellular components
Exergonic
Redox Reaction
NADh
Releases a lot of energy when oxidized that can be used to
make ATP
Can donate electrons during synthesis reactions to energize
them
Ae- + B → A + Be- A is oxidized, B is reduced
Oxidation – removal of electrons
Reduction – addition of electrons
Anabolic Reaction
coupled to exergonic reaction
Synthesis cellular components
Endergonic
