Intro to metabolism Flashcards
What is photosynthesis
Plants capture energy from the sun and store it in the chemical bonds of sugars and other food molecules
Cellular Respiration
Organisms release energy stored in the chemical bonds of food molecules they eat (or the sugar they produce in photosynthesis) and use it as fuel
What is potential energy
energy that matter possesses because of its location or structure
what is kinetic energy
energy associated with random movement of atoms or molecules
what is chemical energy
potential energy available for release in a chemical reaction
What is the general definition of metabolism
it is the totality of an organisms chemical reactions
what is a metabolic pathway
it begins with a specific molecule and ends with a product. Each step is catalyzed by a specific enzyme
What are Catabolic pathways?
they release energy by breaking down complex molecules into simpler ones
(cellular respiration)
Exergonic process
What are anabolic pathways?
They consume energy to build complex molecules from simpler ones
(photosynthesis)
Endergonic
What is the general definition of energy?
the capacity to do work or cause change
What is a system and the surroundings?
the system is the matter under study and the surroundings is everything outside of that
What is the first law of thermodynamics
energy can be converted and transformed but cannot be created or destroyed
what is the second law of thermodynamics?
Every energy transfer increases the entropy of the universe
What occurs in a spontaneous process of energy transformation?
the more orderly forms are less stable and are converted into a less ordered and more stable form
What is free energy
it is a measure of a systems instability and its tendency to flow into a more stable state
When can a spontaneous process occur?
When it is moving toward equilibrium
When does free energy decrease?
during a spontaneous process
What does it mean when G is positive
products have more free energy than reactants
it is non spontaneous
it is endergonic
What does it mean when G is negative
Products have less free energy
it is spontaneous
it is exergonic
whats the difference between endergonic and exergonic
endergonic reactions require energy
exergonic reactions release energy
How does ATP release energy?
When the terminal phosphate groups break by hydrolysis
this produces a lower free energy state since the phosphate groups repel eachother and have higher potential energy
how does ATP power cellular work?
by coupling exergonic (spontaneous) reactions to power endergonic (non-spontaneous) reactions
what are the three types of work a cell does?
chemical (synthesis of polymers)
transport (pumping of substances across a membrane against its concentration gradient
Mechanical: movement of chromosomes during mitosis, cilia and flagella, contraction of muscles
ATP hydrolysis drives
endergonic reactions
