Metabolic Pathways
What is the definition of metabolism?
the totality of an organism's chemical reactions
What is the definition of energy?
the capacity (ability) to do work
What is the definition of thermodynamics? And what are the 2 parts of thermodynamics?
the study of the energy transformations that occur in a collection of matter
parts:
system (organism)
universe (everything else)
What is the definition of Gibbs free energy and what is the formula?
the proportion of a system that can perform work when temperature and pressure are uniform throughout the system
delta G= delta H - T(delta S)
H=total energy, T=temperature (Kelvins), S=entropy
What is a key feature in the way cells manage their energy resources to do work, and what is a brief definition?
energy coupling: the use of exergonic (release energy) process to drive on endergonic (absorb energy) one
What is the definition of metabolic pathways? Could you draw the model that was on the slides?
a specific molecule is altered in a series of defined steps, resulting in a product
Temperature and friction would be an example of what form of energy?
thermal
What is biological order and disorder? Give an example.
cells create ordered structures from less organized starting material (simpler material to more complex)
example: glass sponge which inspired the La Sagrada Familia Towers
What are the 3 types of spontaneous Gibbs free energy? Give brief definition or example of each.
gravitational motion: from higher altitude to lower
diffusion: molecules in a drop of dye diffuse until they are randomly dispersed
chemical reaction: glucose molecule is broken down into simpler molecules
What is the currency for energy and what are its 3 components?
adenosine triphosphate (ATP)
components: 3 phosphate groups, ribose, adenine
Large molecules are broken into small ones. Energy is released.
What type of metabolic pathway is this?
Catabolic
What type of energy is photosynthesis and what is the formula for photosynthesis?
chemical energy
6H2O + 6CO2 ----> C6H12O6 + 6O2
water + carbon dioxide -----> sugar + oxygen
What is the first law of thermodynamics and what is it also known as? Draw and label the bear example used in class.
energy can be transferred and transformed, but it cannot be created or destroyed
aka: principle of conservation of energy
A spontaneous chemical reaction, in which there is a net release of free energy is what type of reaction? Draw and label a graph to illustrate, and give example.
exergonic reaction (catabolic) (less stable to stable)
example: cellular respiration
What are the 3 kinds of work that cells do? And a brief description or example of each.
chemical: chemical reactions, pushing endergonic reactions (photosynthesis)
transport: active transport, against concentration gradient (sodium-potassium pump)
mechanical: movement, beating of cilia, chromosomes, flagella, muscle contractions (microfilaments)
Small molecules are assembled into large ones. Energy is required.
What type of metabolic pathway is this? And provide an example?
Anabolic
example: photosynthesis
potential
diver picture: a diver has more potential energy on platform than in water, diving converts potential to kinetic, a diver has less potential energy in water than on platform, climbing up converts kinetic to potential
What is a spontaneous and non-spontaneous process? Draw an example of both.
spontaneous: a process that occurs without an overall input of energy; energetically favorable; exergonic (picture: ball rolling downhill)
non-spontaneous: a process that cannot happen without input of energy into the system; energetically unfavorable; endergonic (picture: rolling a ball uphill)
A non-spontaneous chemical reaction, in which free energy is absorbed from the surrounding is what type of reaction? Draw and label a graph to illustrate and give an exmaple.
endergonic reaction (anabolic) (more stable to less)
example: photosynthesis
What is the ATP cycle? Draw and label it
ATP hydrolysis to ADP and P yields energy, energy for endergonic, ATP synthesis from ADP and P requires energy from exergonic reactions
What are the 2 types of metabolic pathways? And give a brief definition and example of both.
Catabolic pathways: a metabolic pathway that releases energy by breaking down complex molecules to simpler molecules (cellular respiration: hydrolysis)
Anabolic pathways: a metabolic pathway that consumes energy to synthesize a complex molecule from simpler molecules (photosynthesis: dehydration)
What are the types of energy and a brief definition of each?
Kinetic energy: energy of motion
Thermal energy: kinetic energy associated with random movement of atoms or molecules
Potential energy: stored energy
Chemical energy: potential energy available for release in a chemical reaction
What is the second law of thermodynamics and the definition of entropy? Draw and label the bear example used in class.
every energy transfer of transformation increases the entropy of the universe
entropy: a measure of disorder (randomness)
Draw and label an isolated hydroelectric system, an open hydroelectric system, and multiple open hydroelectric system. How does this demonstrate equilibrium, and why must we prevent delta G=0?
isolated: delta G=0, no work can be done on in living organisms
open: creates metabolic disequilibrium (prevents delta G=0)
multistep: similar to cellular respiration
What is the definition and function of enzymes, and what model demonstrates enzymes high specificity?
a macromolecule that acts as a catalyst, a chemical agent that speeds up chemical reactions without being consumed by the reaction
lowers the activation energy (energy required to initiate a chemical reaction)
induced fit model or lock & key model