2 Lecture 3 Flashcards
a brief overview of the first law of thermodynamics
1— states that energy can be neither created or destroyed
energy can change forms, and energy can flow from one place to another
a particular consequence of the law of conservation of energy is that the total energy of an isolated system does not change
Types of Energy
kinetic potential (stored energy, energy that could do work) mass, gravity, speed elastic chemical e.g. chemical binds, ATP radiant e.g. sunlight, photosynthesis thermal e.g. sunlight, thermal regulation the sum of Energy (Etotal) = KEsystem (kinectic energy) + PEsystem (potential energy) = Usystem (microscopic energy)
what is Energy Transfer
the transfer of energy is described as work and heat
what requires energy transfer
everything
forming a bond requires energy transfer
breaking a bond requires energy transfer
what is joule
is the amount of heat required to raise the temp. of 1 gram of water by 0.24 degree C
what is A calorie
is the amount of energy required to raise the temperature of 1 gram of water by 1°C.
Unit of energy represented on food labels
Calories are consumed by cells to do work
Extra calories can be stored as fat
what is Metabolic rate:
the rate at which the body uses energy
what is Basal Metabolic Rate or BMR
represents the resting energy of an awake, resting but alert person
Metabolic rate is influenced by many factors such as
Body weight, sex, exercise, genetic makeup, age, and nutritional status
what do calories turn into?
heat to keep you warm, molecules thatch be used to build other molecules, chemical bonds, all kinds of things, everything turns into everything, energy turns to energy
what is Metabolism:
all chemical reactions occurring in the body
what are Enzymes
are proteins that catalyze (speed up) chemical reactions in the cell
how do Enzymes work
by lowering the activation energy (aka energy barrier) needed for a reaction
what is an energy barrier
in order to change shape, protein needs energy (a certain amount of energy) and if it doesn’t have that energy it won’t be able to change shape)
what is a reaction
Substrates are the substances being catalyzed
the active site is where the substrate binds to the enzyme
the product is released leaving the enzyme free to bind another substrate
what is induced fit
The binding of the substrate and enzyme causes a shape change
what is Specificity
of the enzyme to the substrate is based on enzyme shape and active site
what is the basic summary of enzymes
enzymes speed up the rate of a reaction (or rate of product production) by reducing the energy required for the reaction to occur
enzymes do not create reactions that would not occur in their absence
how is energy transferred
Cellular respiration (more on this later) is a series of chemical reactions that convert chemical energy from food into chemical energy in ATP (the energy currency of the system)
what does ATP consist of
ATP consists of adenine, a sugar, and 3 phosphate groups
at the end of ATP, the end Phosphate is kind of snipped off, where does it go
the end Phosphate is kind of snipped off (the bond is broken), and where does it go? It goes on to another thing (like a sugar or another substance)
When a phosphate group is transferred from ATP to another molecule (phosphorylation), what happened
energy is transferred and ADP is produced
what is ATP good for
The energy from ATP can power different kinds of work in the cell. example: mechanical work
