Chapter 5
The Working Cell
• What do Fireflies have
to do with energy?
• The light flashes they
create require energy
• What is the main
reason for producing
the light flashes?
• Males flash to attract
females
• Why is this female
eating a male?
• She has attracted
another species and
decreases competition
by getting rid of it.
• What type of insect is
a firefly?
• A beetle
• What are the two
components necessary for
the firefly to make light?
• Luciferin and the enzyme
luciferase
• What does luciferase need
to catalyze the reaction?
• Oxygen and energy from
ATP
• What do all cells need to
have to survive?
• Membranes
• What is the definition of
energy?
• Energy is the capacity to do
work
• What kind of energy does
pedaling a bicycle require?
• Kinetic - the energy of
motion
• Name two kinds of kinetic
energy
• Light and heat
• How can an object at rest
have energy?
• It has potential energy
• What is the most
important type of energy
for living organisms?
• Chemical energy - the
potential energy of
molecules
• What is an energy
transformation?
• When energy is changed
from one form to another.
• Give two examples of
energy transfers
• Gas burns to release kinetic
energy that pushes the
pistons, Sugar is rearranged
to form other molecules
releasing energy. Potential
is converted to kinetic in
these examples
• Explain how 217 big
macs could power a
car for 88 miles?
• The potential energy
in the bonds of the
polymers of 217 Big
Macs can be converted
into kinetic energy
• How do the two
cheetah pictures
illustrate energy
transformation?
• The cheetah has
potential energy
obtained from food
and transfers that to
kinetic energy when it
runs
• What is the 1st law of
thermodynamics?
• Energy cannot be created
or destroyed
• How does the pumping of
gas or drinking of a soda
illustrate this law?
• The gas or soda will be
converted into energy to
power the car and the
woman
• What is the second law of
thermodynamics?
• The entropy (disorder) of
the universe is increasing.
• What does that mean?
• Basically, no energy
transformation is 100%
efficient. Heat is
disordered energy and
increases the disorder of
the universe
• Animation and another
Which has more potential
energy in the graph, the
reactants or products?
The products
What type of reaction has
more energy in the
products?
Endergonic
Give an example of an
endergonic reaction
Photosynthesis
• Which has more energy in
the graph, the reactants or
products?
• The reactants
• What type of reaction has
more energy in the
reactants?
• Exergonic
• What does this mean?
• It releases energy
• Why does ATP break
apart so easily?
• Three negative P
together is not very
stable
• What else happens
when the phosphate
comes off?
• Energy is released
• What is energy coupling?
• It is when a really exergonic
reaction is used along with an
endergonic reaction to make the
endergonic reaction happen
• Explain how ATP is coupled to
the movement of a protein
• The phosphate comes off the
ATP and temporarily stays on
the protein, as the protein
knocks it off it moves`
• Exergonic reaction
produce ______ while
endergonic reactions use
____ and release ______
and ___
• ATP, ATP, ADP, P
• If we couple these
reactions we can give
enrgy from an exergonic
reaction to an endergonic
reaction and make it
happen
• What type of reaction is
illustrated by the picture?
• Exergonic because the
reactants have more
energy than the products
• What is the barrier called
that prevents many
exergonic reactions from
happening?
• Activation energy- like the
push you have to give a
ball to get it to start rolling
down hill.
• How do enzymes
catalyze reactions?
• They lower the
activation energy- they
grab onto the reactants
and make them react.
How enzymes work
• What is the reactant in
this reaction?
• Sucrose
• What are the products?
• Glucose and fructose
• What process did this
enzyme catalyze?
• The hydrolysis of
sucrose
sucrase
• What are two ways an
enzyme can be stopped?
• Something that looks like
the substrate (reactant) or
something that binds to
another spot and changes
its shape so it cannot bind
its substrate
Stopping enzymes
Competitive inhibition
Noncompetitive
• What are the main
components of the cell
membrane?
• Phospholipids and
proteins
• What is so special
about a phospholipid?
• They have
hydrophobic tails and
hydrophilic heads.
• Two layers of
phospholipids end to end
are called?
• A bilayer
• What kind of things would
be repelled by the bilayer?
• Anything that is charged
or hydrophilic because it
can’t get through the
hydrophobic tails
• What is the purpose of a
carbohydrate on the
surface of the membrane?
• They act as markers or
recognition factors like
A,B or O blood type
• What does cholesterol do
for the membrane?
• Allows for space in
between the tails making it
more fluid
membrane fluidity
• Define diffusion
• The tendency for particles
to move from high
concentration to lower
concentration
• What is the difference
between diffusion and
passive transport?
• Passive is diffusion across
a membrane and can
include facilitated
difussion
• What is osmosis?
• Diffusion of water
across a membrane
• What is hypertonic?
• High solute low water
• What is hypotonic?
• Low solute, high water
• What happens when you put an
animal or plant cell in a
hypotonic solution?
• The animal cell will swell and
burst, the plant cell actually
becomes turgid
• What happens to cells in a
hypertonic solution?
• They lose water and shrivel
• What do you think flaccid
means?
• Limp
• What process is going on
when a transport protein
helps move a substance
along its concentration
gradient?
• Facilitated diffusion
• Is this active or passive
transport?
• Passive because it does
not require energy
• What type of transport
requires energy and
moves a particle
against its gradient
(low to high)?
• Active transport
• What is it called when
a cell releases particles
to the outside?
• Exocytosis
• What is the process
called when a cell
takes in particles?
• Endocytosis
• What are the 3 types of
endocytosis and how are
they different?
• Phagocytosis - cell eating
• Pinocytosis - cell drinking
• Receptor - mediated - the
material binds to a
receptor and is then
brought into the cell- very
specific
• The picture on the
right shows
cholesterol getting into
the membrane by what
process?
• Receptor mediated
endocytosis