Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
233 Cards in this Set
- Front
- Back
in humans metbolizing cells perform funcitons such as |
digestion muscle movement hormone production
|
|
two types of energy in biology |
potential energy kinetic energy |
|
potential energy examples |
chemical energy (stored in bonds) concentration gradient across a membrane |
|
kinetic energy examples |
light sound movement of atoms and molecules muscle contraction |
|
energy allows cells to |
do work |
|
physicists define energy as |
the ability to do work -move matter |
|
the total amount of energy in any object is |
the sum of potential and kinetic energy |
|
potential energy |
stored energy available to do work |
|
kinetic energy |
energy being used to do work |
|
forms of energy are emasured in units called |
calories |
|
one calories is the |
amount of energy required to raise the temperature of 1 gram of water from 14.5c to 15.5 c |
|
kilcalorie(kcal) |
1000 calories |
|
two physical laws that describe the energy conversions vital for life and those that occur in the nonliving world |
-law of energy conservation -all energy transformations are inefficient because every reaction loses some energy to the surroundings as heat |
|
law of energy conservation |
-states that energy can not be created or destryoed -energy an be converted to other forms
|
|
most important energy transformation ins life are |
photosynthesis and cellular respiration |
|
in photosynthesis |
plants and some microbes use carbon dioxide, water, and the kinetic enregy in sunlight to assemble glucose moleucles -glucose (carb molecules) contain potential energy in their chemical bonds |
|
in cellular respiration |
glucose molecules change back to carbon diozide and water, liberating the energy necessary to power life - cells trnaslate the potential energy in glucose into the kinetic energy of molecular motion and use that burst of kinetic energy to do work |
|
second physical law of energy |
all energy transformation are inefficient because every rection loses some energy to the surroundings as heat |
|
law that states all energy transformations are inefficient |
losing energy to heat is inevitable |
|
entropy is a |
measure of the heat energy loss |
|
the more disordered a system is |
the higher its entropy |
|
organisms can increase in compexity as long as |
somthing else decreases in complexity by a greater amount |
|
what are some examples of the work of a cell |
plant cell assemblesglucose molecules into long cellulose fibers moves ions across its membranes
|
|
give examples of potential and kinetic energy in your body |
potential= energy stored in bonds kinetic energy= muscle contraction |
|
what are some energy conversions that occur in cells |
photosynthes and cellular respiration |
|
why does the amount of entropy in the universe always increase |
because organims are highly organized because the sun is constantly supplying energy to earth but entropy of the universe as a whole is always increasing |
|
networks of chemical reactions |
sustain life |
|
metabolism |
encompasses chemical reasctions in cells that build new molecules and that break down exisiting ones |
|
each metabolism reaction |
reaaranges atoms into new compounds - either abosrbs or releases energy
|
|
chemical reactions |
absorb or release energy |
|
reactions that build complex molecules from simpler components typically require |
energy input |
|
if a reaction releases energy the ______ contain less energy than the _______ |
products , reactants |
|
chemical reactions that release energy |
break large complex molecules into their smaller simpler components -cellular respiration is an example (glucose, to co2 and h20) |
|
most energy transformations in organisms occur in |
oxidation reduction reactions |
|
oxidation reduction reactions |
transfer energized electrons form one molecule to another |
|
oxidation |
the loss of electrons from a molecule, atom, or ion |
|
oxidation reaction examples |
glucose to co2 and h20 , rlease energy as they degrade complex molecules into simpler products |
|
reduction |
gain of electrons plus any energy contained in the elctrons - require a net input of energy |
|
oxidations and reductions occur simultaneously because |
electrons removed from one molecule during oxidation join another molecule and reduce it - f one molecule is reduced (gains molecules) then another must be oxidized (loses electrons) |
|
reactions that require energy |
bind small molecules with adding energy |
|
reactions that release energy |
divide bigger molecules with taking out energy |
|
groups of electron carrying proteins align in |
membranes |
|
electron trnasport chain |
each protein accpets n electron from the molecule before it and donates the electro to the next in line -first reduced then oxidized -energy is released as each step
|
|
this plays a key role in both photosynthesis and respiration |
electron transport chian |
|
what is metabolism on a cellular level |
metabolism encompasses chemical reactions that build new molecules and break down old ones |
|
which reactions require energy input and which release energy |
reactions that bind together to make complex molecules typicallly require energy input reactions that break complex molecule apart release energy |
|
what are oxidation and reductino and why are they always linked |
oxidation is the release of electrons reduction is the gain of electrons alwasy linked because electrons are removed from one molecule during oxidation then join another molecule and reduce it |
|
what is an electron transport chain |
electron donor transfers an electron to the first protein and continues to get passed on until a final electron acceptor |
|
atp is |
cellular energy currency |
|
covalent bonds of adenosine triphosphate |
commonly known as atp - temporarily store energy released in chemical reactions |
|
atp |
type of nucleotide based adenine, five carbon sugar ribose, and three phosphate groups -the three phosphates place negative charges very close to one another which makes it unstable so it releases energy when the covlanet bond between the phosphate breaks |
|
in eukarotic cells this creates most of the cells atps |
mitochondria |
|
mitochondrion uses the potential energy in the bonds of one glucose molecule to generate |
dozens of atp molecules in cellular respiration |
|
the cell that contain the most mitochondria |
the most energy hungry cells -muscles and brain |
|
when a cell requires energy for a chemical reaction it spends atp by |
removing the endmost phophate group |
|
adenosine diphosphate |
the product of hydrolysis reaction (removing endmost phosphate group to use atp) |
|
energy can be temporarily stored by adding a |
phosphate to adp, forming atop and water |
|
this is a nucleotide consisting of adenine, ribose, and three phosphate groups |
atp |
|
this drives the reactions that require energy input -those that do work or synthesize new molecule |
atp hydrolysis |
|
cells use atp hydrolysis, a reaction that releases energy, to fuel reactions that |
rewuire energy input |
|
cell generate s atp in other reactions |
such as those that break down food |
|
coupled reactions |
cell uses atp as an energy source by transferring its phosphate group to another molecule - this transfer may either energize the target molecule making it more likely to bond with other molecules or - added phosphate group may change the shape of the target molecule |
|
jobs that require atp include |
tranporting substances across cell membranes movin chromosomes during cell division synthisizing the large molecules that make up cells
|
|
cell can use respiration to |
rebuild its pool of atp |
|
atp represents |
short term energy storage |
|
when atp donates a phosphate group to a molecule the recipient may |
1. be more likely to bond or 2. change its shape in a useful way |
|
this makes atp too unstable for long term storage |
high energy phosphate bonds |
|
how does atp hydrolysis supply energy for cellular functions |
atp hydrolysis liberates a phosphate and releases energy which fuels reactions that require energy input |
|
descrive the relationship between enregy requiring reactions, atp hydrolysis and cellular respiration |
cellular repiration creates atp, atp hydrolysis releases energy which fuels energy requiring reactions |
|
these speed biochemical reactions |
enzymes |
|
an organic molecule that catalyzes (speeds) a chemical reaction without being consumed |
enzyme |
|
most enzymes are |
proteins but some are made of rna |
|
many of cells organelles includeing mitochondria, chloroplasts, lysosomes, and peroxisomes are |
speicalized sacs of enzymes |
|
a few jobs of enzymes |
copy dna build proteis digest food recycle a cells worn out parts catalyze oxidation reduction reaction |
|
enzymes speed reactions by lowering |
the activatio energy |
|
activation energy |
the amount of energy required to start a reaction |
|
the ______ brings reactants (substrates) into contact with one another so that less energy is required for the reaction to start |
enzymes |
|
the lower the activation energy the |
faster the reaction can proceed |
|
most enzymes can catalze only |
specific one or few chemical reactions |
|
active site |
the region to which the substrates bind -the shape of the active site etermines what enzymes can catalyze |
|
reactions do/do not consume or alter the enzyme |
do not |
|
substrates fit into enzymes active sites like |
puzzle pieces |
|
negative feedback / feedback inhibition |
product of a reaction inhibits the enzyme that control its formation |
|
negative feedbacks two general ways of preventing too much of the reaction product from accumulatin |
1. noncompetitive inhibition 2. competitive inhibition |
|
noncompetitive inhibition |
product molecule binds to the enzymes at a location other than the active site |
|
this action alters the enzymes shape so that it can no longer bind the substrate |
noncompetitive inhibition |
|
competitive inhibition |
the reaction product binds to enzymes active site which prevents it from binding substrates - competitive because the product competes with the substrate to occupy the active site |
|
an enzyme cna become denatured and stop working if |
ph changes salt concentration becomes too high or low temperature is too hot pharmaceutical drugs some poisons |
|
what do enzymes do in cells |
copy rna, build proteins, digest food, recycle a cells worn out parts, catalyze oxidation reduction reactions |
|
how does an enzyme lower a reactions activation energy |
an enzyme brings reactants or substrates into contact with one another so that less energy is required for the reaction to start |
|
what is the role of negative feedback in enzyme production |
when the product of a reaction inhibits the enzyme that control its formation, shape, and functionality -change shape of protein or prevents the substrate from entering |
|
this changes the shape of the protein |
noncompetitive inhibitor |
|
this physically blocks the enzymes active site preventing the substrate from entering |
competitive inhibitor |
|
conditions that influence enzyme activity |
ph salt concentration temperature pharmaceutical drugs poison |
|
potential energy is stored in |
chemical |
|
potential energy is highest at |
top of mountain highest point of bulb droping |
|
kinetic energy is highest |
while going down hill while bulb is falling through space |
|
entropy is highest at |
the drop or breaking of light bulb |
|
osmosis is defined as |
water molecules diffusing through a membrane from a high concentration of water to a lesser concentration of water |
|
water molecules being diffused across a membrane from a high water concentration to a low water concentration is known as |
osmosis |
|
these types of molecules will diffuse through the cell membrane the easiest |
small and nonpolar molecules |
|
large and polar molecules have a |
hard time diffusing across a membrane |
|
hypotonic solution has |
more water to solutes |
|
hypertonic solution has |
more solutes to water |
|
red blood cell in a hypertonic solution will |
shirnk |
|
2% acid solution is _______ to a 15% acid solution |
hypotonic |
|
a 13% nickel solution is _______ to a 8% nickel solution |
hypertonic |
|
water moves in and out of the cell at equal rates in this type of solution |
isotonic |
|
this type of energy is stored in chemicals |
potential energy |
|
relations between : active transport ATP energy concentration gradients |
active transport uses ATP to form concentration gradients which is stores potential energy |
|
processes that decrease the amount of potential energy stored across a membrane |
facilitated diffusion simple diffusion |
|
=different ways movement across a membrane occurs |
active transport passive transport transport using vesicles |
|
active transport |
net movement is against concentration gradient; requires transport protein and energy input, often from ATP
|
|
passive transport |
new movment is down concentration gradient does not require energy input |
|
simple diffusion |
substance moves across membrane w/o assistance of transport proteins -goes from area of high concentration to area of low concentration |
|
osmosis |
water diffuses across a selectively permeable membrane from high concentration of water to low concentration of water |
|
facilitated diffusion |
substance moves across a membrane with assistance of transport proteins -from area of high concentation to area of low concentration |
|
this type of diffusion requires transport proteins |
facilitated difusion |
|
this type of transport across a membrane requires energy; typically from ATP |
active transport |
|
transport using vesicles |
vesicle carries molecules into or out of a cell |
|
endocytosis |
membrane engulfs substance and draws it into cell |
|
exocytosis |
vesicle fuses with cell membrane releasing substances outside of cell |
|
endo |
inward engulf |
|
exo |
outward |
|
negative feedback/ feedback inhibition |
a way to regulate a metabolic pathway - the product of a reaction inhiits the enzyme that controls its formation |
|
two types of negative feedback |
noncompetitive inhibition competitive inhibition |
|
noncompetitive inhibition |
a product molecule or inhibitor binds to the enzyme at a location other than the active site whch than alters the enzymes shape so that it can no longer bind the substrate |
|
membrane is |
selectively permeable does not like polar or large molecules |
|
interior of a cel is |
chemically different from the outside |
|
the inside of each organelle in a eukaryotic cell may be |
chemically quite different from the solution in the rest of the cell |
|
concentration gradient |
solute is more concentrated in one region than in a neighboring region |
|
concenration gradient |
dissipates uness energy is expended to maintain it |
|
random molecular motion |
alys increases the amount of entropy |
|
all forms of transport across membranes involve |
gradients |
|
all forms of passive transport involve |
diffusion |
|
diffusion |
the spontaneous movement of a substance from a region where it is more concentrated to a region where it is less concentrated |
|
why does diffusion not require energy input |
because it represents the dissipation of a chemical gradient and the loss of potential energy |
|
diffusion occurs because |
all substances have kinetic energy so they are in constant random motion |
|
diffusion appears to stop |
but the molecules do not stop moving, travel randomly at same rate so at equilibrum the concentration remains equal throuhout the solution |
|
simple diffsuion |
passive transport moves down its concentration gradient does not get aid of a transport protein |
|
substances enter or leave cells by simple diffusion only if |
they can pass freely through the membrane
|
|
lipids and small, nonpolar molecules such as oxygen and carbon dioxide diffuse |
easily across the hydrophiv portion of a biological membrane |
|
cells maintain gradients |
- by continually consuming the substances as they diffuse in -by producing more of the substances that diffuse out |
|
diffusion of water across a selectively permeable membrane |
osmosis |
|
isotonic |
the solute concentration inside the cell is he same as that of the outside |
|
if the solution is hypotonic to the cell |
the external solute concentration is lower than it is inside the cell |
|
hypo |
under |
|
hyper |
over |
|
in a hypertonic enviornment |
a cell loses water shrivels and may even die |
|
the net direction of water movement is from the |
hypotonic solution to the hypertonic one |
|
turgot pressure |
the resulting forced of water against the cell wall
|
|
lost turgor pressure |
limp wilted plant |
|
helps keep plants erect |
turgor pressure |
|
ions and polar molecules cannot freely cross the hydrophbic part of the phospholipid bilayer |
so transport proteins form pores that help these solutes cross |
|
form of passive transport where membrance protein assists the movement of a polar solute along its concentration gradient and does not need energy because it is going down the concentration gradient |
facilitated diffusion |
|
bacteria, plants, and animals use |
membrane proteins called aquaporins to increase the rate of water flow |
|
this type of transport requires energy |
active transport |
|
in this type of transport - cell uses a transport protein to move a substance against its concentration gradient goes from where it is less concentrated to where it is more concentrated |
active transport |
|
cells must contain high conenctrations of ____, and low concentrations of _______ |
potassium, sodium |
|
one active transport system in the membranes of most animal cells is a proein called |
sodium-potassium pump -uses atp as an energy source to expel three Na+ for every two K+ it admits |
|
endocytosis and exocytosis |
use vesicles to transport substances |
|
vesicles used to transport substances |
are small sacs that can pinch off of or fuse with a cell membrane |
|
endocytosis |
allows a cell to engulf fluids and large molecules and bring them into the cell -molecules push on cell membrane and the indentation then becomes a indepenedant bubble of membrane that encloses on itself |
|
two main forms of endocytosis are |
pinocytosis and phagocytosis |
|
pincytosis |
cell engulfs small amounts of fluids and dissolved substances |
|
phagocystosis |
cell captures and engulfs large particles such as debris or even another cell -veiscle then fuses with lysosome where dyrolytic enzymes dismantle the cargo |
|
large particles enter a cell by |
endocytosis |
|
white blood cells doing their job is an example of |
endocytosis |
|
exocytosis |
uses vesicles to transport fluids and large prticles out of cell |
|
in exocytosis, the ______ produces vesicles filled with substances to be secreted |
golgi appartaus |
|
vesicle moves to the cell membrane and joins with it releasing the substance outside the membrane |
exocytosis |
|
what is diffusion |
the spontaneous movement of substances from where there is a high concentration to a low concentration |
|
what type of substances diffuse freely across a membrane? |
-polar, small, and lipid substances |
|
how do differing concentrations of solutes in neighboring solutions drive osmosis? |
the solution differences determine whether the relationship is isotonic, hypotonic, or hypertonic |
|
why does it cost energy to maintain a concnetration gradient? |
because entropy is always increasing, you must put energy to reverse these effects |
|
distinguish between simple diffusion, facilitated diffsuion, and active transport |
simple diffusion= no protein aid, no energy input, passive transport, polar small molecules pass through easily, moves down concentration gradient facilitated diffusion= has protein aid, no energy input, passive transport, moves down concentration gradient active transport= requires energy, moves up conenctration gradient ( goes from low concentration to high concentration), requires atp ususally |
|
all cells |
capture and use energy |
|
potential energy |
stored energy |
|
kinetic energy |
is action |
|
energy is measured in units called calories |
one food calories is 1000 calories or 1kcal |
|
energy is converted from one form to another |
energy cannot be created or destroyed but only converted to other forms |
|
every reaction inreases |
entropy and loses energy as heat |
|
the sum of the chemical reactions in a cell |
metabolism |
|
chemical reactions absorb or release energy |
true |
|
in reactions that require energy input |
the products have more energy than the reactants |
|
in reactions that release energy |
the products have less energy then the reactants |
|
linked oxidation and reduction reactions form |
electron transport chains |
|
many energy transformations in organisms occur via |
redox reactions |
|
the loss of electrons |
oxidation |
|
gain of electrons |
reduction |
|
in photosynthesis and respiration, proteins shuttle electrons along |
electron transport chains |
|
cellular energy currency |
atp |
|
_______ stores energy in its high energy phosphate bonds. cellular respiration generates this |
ATP |
|
cells use the energy released in ____________ to drive other reactions |
ATP hydrolysis |
|
this represents short term energy storage |
ATP |
|
cells store energy as |
fats and carbohydrates |
|
the faulty membrane protein that causes cystic fibrosis may help protect against |
choler |
|
building proteins _______ energy |
requires |
|
ATP hydrolysis _________ energy |
releases |
|
proteins contribution to the function of an electron transport chain |
they become oxidized and reduced |
|
where in a molecule of ATP is the stored energy that is used by the cell |
in the covalent bonds between the phosphate groups |
|
the role of an enzyme in a cell |
to speed up chemical reactions |
|
the active site is unaable to bind substrate |
in noncompetitive inhibition |
|
the movement of water molecules during osmosis is due to |
diffusion |
|
ions and polar molecules need __________ diffusion across membrane |
facilitated diffusion |
|
substances that diffuse freely across a membrane |
nonpolar, small molecules and lipids |
|
concentration gradient is an example of |
potential energy |
|
some people claim that the high degree of organization defies the physical law that says entropy always increases. what makes this statement false? |
this statement is only valid if organisms are closed and organisms can increase in complexity as long as something else decreases in complexity by a greater amount |
|
atp is energy currency |
you spend ATP to fuel chemical reactions |
|
how do enzymes speed chemical reactions |
enzymes copy dna, build proteins, digest food, recycle a cells worn out parts, and catalyze oxidation reduction reactions - they bind to substrates which then releases the production |
|
fat digesting enzymes are not able to digest a artificial fat because |
artifical fat has a different shape than that of a normal fat so the digestive enzyme would not recognize the artificial fat |
|
chemical structure of ATP |
3 phosphate groups, ribose, adenine nucleotide
|
|
how does atp hydrolysis supply energy for cellular function |
hydrolysis of atp breaks the bond of atps endmost phosphate group, releasing energy |
|
atp that is produced in cellular respiration can be hydrolyzed to release energy that can be used to drive endergonic reactions (reactions that require energy input) |
atp that is produced in cellular respiration can be hydrolyzed to release energy that can be used to drive endergonic reactions (reactions that require energy input) |
|
these speed up chemical reactions (catalyze) without being consumed in the process |
enzymes |
|
how do enzymes lower a reactions activation energy |
enzymes bring reactants into contact of eachother so that less energy is required to start the reaction |
|
conditions that effect an enzymes activity |
pH, temperature, and salt concentration |
|
It costs energy for a cell to maintain a concentration gradient because |
it must move substances against diffusion, which tends to allow gradients to dissipate |
|
endocytosis and exocytosis function by |
binding lipid bilayer that surrounds vesicles with lipid bilayer of the cell membrane |
|
endergonic reactions |
require energy |
|
exergonic reactions |
release energy |
|
Enzymes speed chemical reactions by |
lowering the energy of activation, the amount of energy required to start a reaction. |
|
Why does poking a hole in a cell’s membrane kill the cell? |
cell membrane holds together the cells internal enviornment -a hole in the cell membrane would allow organelles and dissolved chemicals to leave, and the cell would die |
|
diffusion is efficient only over |
small distances and as long as all parts of the cells interior are close to the surface of the cell |
|
the chemical bond energy in ATP is a form of __________ energy |
potentinal energy |
|
example of entropy |
heat energy being lost at each step of energy conversion |
|
an example of kinetic energy |
sunlight |
|
sunlight creates photosynthesis which binds with oxygen to create glucose which then goes to cellular respiration which transforms to potential energy or carbon dioxide and water and then repeats the cycle |
cycle of energy conversion |
|
when products contain more energy than reactants |
it is a reaction that requires energy input or endergonic reaction |
|
when reactants contain more energy than products |
it is a reaction that releases energy or exergonic reaction |
|
an example of a energy requiring reaction |
photosynthesis |
|
an example of an energy releasing reaction |
cellular respiration |
|
example of potential energy |
glucose |