Ch 6-1 Flashcards
How does bioluminescence work
Some organisms convert chemical energy to light
Ex: dinoflagellates
Metabolism meaning
Sum of all chemical rxn in an organism
= emergent property
What does metabolic pathway alter
Alters a molecule through a series of defined steps, each of which involves the action of a specific enzyme
Catabolic pathway meaning
Release energy
Destroy molecules (complex to simple)
Anabolic pathways meaning
Requires energy input
(Creating simple to complex compounds)
The study of how energy flows through living organisms
Bioenergetics
Energy is the ability to
Cause change
Energy has the ability to
Rearrange matter
Ex: moving substances across a cell membrane
Forms of energy (5)
- Kinetic energy = movement of objects
- Thermal energy = KE due to random motion of atoms and molecules
- Heat = thermal energy transferred from one object to another
- Potential energy = due to location/structure of matter
- Chemical energy = potential energy stored in chemical bonds
True or False: Anabolic pathways break down complex molecules into simpler ones.
False (That describes catabolic pathways).
What is the difference between catabolic and anabolic pathways?
Catabolic pathways release energy by breaking down molecules, while anabolic pathways consume energy to build molecules.
What is bioenergetics
Study of how energy flows through living organisms
Chemical energy meaning
Energy stored in chemical bonds
Form of energy associated with with movements of objects
Kinetic energy
True or False: Plants convert light energy into chemical energy through photosynthesis.
True
What is potential energy
Energy that matter has because of its location or structure.
What is thermal energy
Kinetic energy due to random motion of atoms and molecules
Thermal energy transferred from one object to another
Heat
First law of thermodynamics
Energy can be transferred and transformed, but it cannot be created or destroyed.
True or False: Every energy transfer increases the disorder (entropy) of the universe.
True
What does entropy measure
The level of molecular disorder in a system.
How do living organisms maintain order without violating the laws of thermodynamics?
By releasing heat and increasing the entropy of their surroundings.
What is an example of a process that increases entropy
Digestion or decay
What is Gibbs free energy (G)
The portion of a system’s energy that can perform work when temperature and pressure are uniform.
How does a spontaneous rxn relate to Gibbs free energy
A spontaneous reaction occurs without energy input and has a negative ΔG.
What are the two components of thermodynamics and describe them
- System : collection of matter being studied
- Surroundings: everything outside of that system
When is energy required in spontaneous process
When it is not spontaneous
What is free energy
Portion of systems energy which is able to do work when pressure and temp are kept constant within the system
When can the entropy of an indiv system decrease
As the total entropy of the universe increases
What does a negative gibbs mean
No energy is required to cause a rxn = spontaneous
In order to have a negative Gibbs, free energy must be __
Lost from the system
When is equilibrium reached
When a system is in its most stable state (equal forward and reverse rxn)
Free energy is at its lowest possible value
Any changes increases what
Free energy (G)
METABOLISM REACHES EQUILIBRIUM (T OR F)
FALSE
HOW DOES CELL PREVENT REACHING EQUILIBRIUM
Reactants and added products are removed
True or False: Living cells are closed systems and eventually reach equilibrium.
False (Living cells are open systems and do not reach equilibrium).
How is free energy related to stability in a system?
Less free energy equals more stability.
What type of reaction absorbs free energy from its surroundings?
Endergonic
What type of reaction releases free energy to its surroundings?
Exergonic
What is a metabolic pathway?
A series of chemical reactions in which the product of one reaction becomes the substrate for the next.
True or False: Catabolic pathways are spontaneous and produce energy.
True
Give an example of an anabolic pathway.
Photosynthesis
Give an example of a catabolic pathway.
Cellular respiration
What is the role of enzymes in metabolic pathways?
Enzymes speed up reactions by lowering activation energy.
True or False: Thermal energy is a type of potential energy.
False (It is a type of kinetic energy).
What is the source of energy for photosynthesis?
Light energy
How does potential energy convert to kinetic energy in a biological context?
Stored energy in molecules (potential) is released during reactions (kinetic).
True or False: Heat is a form of energy that can do work in cells.
False (Heat energy is often lost and increases entropy).
What is chemical energy stored in
Chemical bonds
What molecule is considered the energy currency of the cell?
ATP
True or False: ATP hydrolysis is an exergonic reaction.
True
What does ΔG represent in a reaction?
Change in free energy
True or False: Cells can store the energy from catabolic reactions for anabolic processes.
True
What is a phosphorylated intermediate?
A molecule that has received a phosphate group from ATP, making it more reactive
What is the second law of thermodynamics?
Every energy transfer increases the entropy of the universe.
What happens when a process increases entropy on its own?
It occurs spontaneously without the need for energy input.
True or False: In an isolated system, reactions eventually stop doing work once equilibrium is reached.
True
What type of system are living cells?
Open systems (reactants are added, and products are removed).
What is the relationship between free energy and work capacity?
More free energy means greater work capacity.
True or False: An endergonic reaction requires energy input.
True
What is the energy transformation in photosynthesis?
Light energy to chemical energy.
How do cells prevent equilibrium in their metabolic pathways?
By continuously removing products and adding reactants
Name the two laws of thermodynamics relevant to biology.
First law (energy conservation) and second law (increased entropy).
True or False: Organisms are closed systems that maintain low entropy.
False (Organisms are open systems that increase the entropy of their surroundings).
What is chemical work
Creating of larger molec (endergonic, nonspontaneous)
What is transport work
Movement of substances across the cell memb against gradients (active transport)
What is mechanical work
Movement of cellular components or whole cells (cilia, flagellum, cytoskeleton components)
Energy coupling meaning
process in which energy released from one reaction is used to power another reaction that requires energy
How to not run out of ATP
Cells regenerate molec by coupling its production w/ other catabolic rxn (exergonic)
__ is endergonic, thus not a spontaneous rxn = energy is rqrd
Biosynthesis
