Lecture 7 - Biological Energy Flashcards
stored energy available to do work
potential energy
(< , >) covalent bonds = > potential energy
>
energy being used to do work
kinetic energy
list 4 examples of kinetic energy
movement, light (photons), heat, electricity
List the 2 Laws of Thermodynamics
First: all energy is conserved
Second: all energy transformations are inefficient
Which Law of Thermodynamics:
- energy can’t be created nor destroyed
- only converted to other forms (burning wood)
- energy transformations sustaining life are similar in all organisms
First
Which Law of Thermodynamics:
- lose some energy as heat
entropy (organization to disorganization) - organisms must use incoming energy & matter to remain organized
Second
Describe Entropy
randomness, high to low concentration (organized to disorganized)
True/False: The Second Law of Thermodynamics explains that organisms must use incoming energy & matter to remain organized
True
sum of all reactions in cells
metabolism
product of one reaction becomes substrate of another
chemical reactions
two types of chemical reactions
endergonic, exergonic
endergonic or exergonic
absorbed
endergonic
endergonic or exergonic
released
exergonic
endergonic or exergonic
- releases energy
- break apart large, complex molecules
- cellular respiration
exergonic
endergonic or exergonic
- require energy to proceed
- build complex molecules
- photosynthesis
endogonic
endergonic or exergonic
kinetic –> potential
endergonic
endergonic or exergonic
potential –> kinetic
exergonic
endergonic or exergonic
Dehydration Synthesis
endergonic
endergonic or exergonic
Hydrolysis
Exergonic
when exergonic reaction gives energy to an endergonic reactions
coupled reaction
coupled reaction:
in order to make the covalent bond you’ve got to break the _______ bond
covalent
coupled reaction:
glucose broken down becomes _____
ATP
@ body temperature many spontaneous reactions proceed too slowly to sustain life
- biological catalysts
enzymes (proteins)
True/False: enzymes help facilitate and make reactions easier
True: they’re biological catalysts
when an active enzyme is prevented from binding to a substrate by an inhibitor
enzyme inhibition
2 types of enzyme inhibitors
- cyanide
- penicillin
inhibits a specific bacteria enzyme
penicillin
inhibitor that blocks ATP synthesis
cyanide
True/False: 2 enzymes can do the same thing
FALSE! No 2 enzymes can do the same thing
are enzymes destroyed after doing they’re job
no
how do enzymes lose function
through denaturation
– Most reactions can proceed in both directions
– If reactants accumulate, the reaction goes forward and vice versa
– At _____________, reaction goes in both directions at the same rate
– Cells must remain far from _________
chemical equilibrium
equilibrium
Use and Production of ATP
- Carbohydrates and fats are more stable energy storage molecules that, when degraded, are used to generate ATP
- Because of its instability, ATP provides only short term storage of energy
region where reactant (substrate) binds
- specific fit
- reaction doesn’t alter enzymes
active sight
protein that catalyzes a chemical reaction without being consumed
enzyme
amount of energy required to start a reaction
activation
Cell Membrane Transport:
concentration gradient:
membranes:
concentration gradient:
solute = > concentrated in 1 region than another
membranes: selectively permeable
form of passive transport not using a carrier protein = freely pass through membrane
simple diffusion
O2 and CO2 dissolve in water and freely move to enter and leave blood in lungs or tissues
Simple diffusion
simple diffusion of water across a membrane
osmosis
passive transport in which a membrane protein assists solute movement along concentration gradient
facilitated diffusion
Does facilitated diffusion require energy
no
what kind of transport does glucose use
facilitated diffusion: because it’s too hydrophilic to pass through the membrane unassisted
how do aquaporins enhance osmosis
allows H2O to diffuse at much higher rate
True/False: diffusion is entropy
True high –> low
3 types of osmosis
isotonic solution
hypotonic solution
hyertonic solution
Type of osmosis:
solute concentration lower outside cell
hypotonic solution
Type of osmosis:
solute concentration higher outside cell
hypertonic solution
Type of osmosis:
concentrations equal inside and outside the cell
isotonic solution
Type of osmosis:
H2O doesn’t enter or leave = cell stays same size
isotonic solution
Type of osmosis:
H2O leaves cell = cell shrinks
hypertonic solution
Type of osmosis:
H2O enters cytoplasm = cell swells
hypotonic solution
ability of a substance to cause H2O movement
tonicity
What type of transport:
- Na+ and K+ pump: uses ATP to expel 3Na+ for every 2K+
- uses 25% of cell’s ATP
- gradients can be used as source of potential energy - ATP synthase in photosynthesis and cellular respiration
Active Transport
process of taking substances into a cell by surrounding it with the cell membrane
endoxytosis
when cell is getting rid of bulk amouns/large molecules of material
exocytosis
