Ch 6 and Ch 8 Flashcards
metabolic pathways
produce energy through chemical ractions
catabolic pathways
degrade complex molecules, break their bonds for energy
anabolic pathways
build complicated molecules, consume energy and store in the bonds
bioenergetics
how energy flows through living systems
kinetic energy
moving energy that can produce work, when molecular bonds are broken
chemical potential energy
resting energy that is being stored, when molecular bonds are created and energy is stored in them
isolated system
can’t exchange energy with its surroundings
open system
exchanges energy with its surroundings
why cells are open systems
they absorb light and chemical energy, release heat and metabolic waste
first law of thermodynamics and biology
byproducts of cell metabolism increase entropy
free energy change
free-energy is what does the work when temperature and pressure are uniform, responsible for spontaneous changes
free energy and reactions
in order for the reaction to be spontaneous, the change in free energy must be negative; free energy tells us if a reaction can occur spontaneously this way
exergonic
when change in free energy is negative and spontaneous reactions can occur; the change in G is the maximum amount of work the spontaneous reaction can do
endergonic
absorbs free energy from the environment; when change in free energy is stored and positive
metabolism and equillibrium
living things must always be an open system that is in disequillibrium
cellular work
is powered by ATP and the progression of exergonic and endergonic reactions; the hydrolysis of ATP produces heat and proteins use energy to do work
work that proteins can do when given energy from ATP
chemical work, transport work, mechanical work
protein chemical work
if the change in free energy of the chemical relationship is less than the energy from the ATP, the chemical relationship’s bonds are broken
protein transport work
ATP changes the shape of the proteins so it can bind to other molecules,transports solutes through the transport proteins
ATP/ADP cycle
starts as ADP, adds a phosphate and produces water; when need energy, breaks bond of third phosphate, releases energy, and becomes ADP again
protein mechanical work
ATP changes the shape of the proteins so it can bind to other molecules, makes motor proteins move
role of enzymes
speeds up hydrolysis and bonding of chemicals as a catalyst; reusable
activation energy and chemical reactions
to break bonds it requires a certain amount of energy called activation energy; frequently the activation energy is absorbed as thermal energy
activation energy and enzymes
enzymes lower the amount of activation energy required by making the reaction occur more easily
enzyme specificity
enzymes only react with their designated substrate like a puzzle piece
induced fit model
as substrate approaches the enzyme, the enzyme moves around the substrate to make a snug fit and catalyze better
how enzymes lower the required activation energy
provides a template for molecules to fit together, stretches the bonds so easier to break, optimal reaction environment
how to increase the digestion of substrates with enzymes
must add more enzymes to increase rate (assuming correct pH and temperature)
