Lesson 6.1
Energy for Cells
1. In the Everyday world,
where do activities that
require energy get that
energy?
The energy our cells use
must come from some
energy releasing event.
2. How are living cells
like a motor?
The energy that causes the
motor to turn started out as
stored energy in some fuel
source. Once the energy in
the fuel source is released,
the motor will move.
The energy our cells use, is
stored in Sugar molecules.
We can use the energy until
the stored sugar energy is
released.
Free Energy!
3. What is FREE ENERGY?
The energy that has been
released from storage and is
available to do work.
4. List three examples of
cells using free energy:
Contraction of muscle cells
Active Transport
Protein Synthesis
5. What are
ENDERGONIC
REACTIONS?
Those chemical reactions
that require free energy in
order to occur = endergonic
reactions.
6. Why do endergonic
reactions require free energy
to be added to them?
Endergonic reactions
require this input of free
energy because the
PRODUCTS of endergonic
reactions have MORE
POTENTIAL ENERGY
than the reactants.
10 J + 10 J
10J
Free energy
30J
7. Where does “Free
Energy” Come From?
From some
Energy-Releasing Event!
8. What are exergonic
reactions?
“Any chemical reaction that
Releases energy as it occurs”
9. Why are endergonic
reactions dependent upon
exergonic reactions?
.An endergonic reaction will
not have the energy to occur,
until a nearby exergonic
reaction releases free energy.
10. Explain what happens
during the exergonic
reactions that releases the
free energy that is needed by
the endergonic reactions:
In cells, the free energy to
drive endergonic reactions
comes from the Breakdown of ATP.
11. What does “ATP” stand
for?
Adenosine Triphosphate
12. Write and label the
structural model that is
used to represent ATP;
A
Adenosine
P
Phosphate
P
Phosphate
P
Phosphate
13. What happens when the
bond between two
phosphate groups is broken?
Energy is
released!
A
P
P
P
14. Explain the exergonic
reaction that occurs during
hydrolysis:
a) Water and ATP come in
contact.
b) The last phosphate group
is broken off of the ATP
c) Energy is RELEASED
d) ATP becomes:
ADP + P1
15. Write the equation that
illustrates the exergonic
reaction that occurs during
hydrolysis:
ATP + H20 ADP + P1 + Energy
16. List the two biological
processes that use the free
energy given off during the
hydrolysis reaction:
Produce heat in warm
Blooded animals
Power Active Transport
17. What is a
Phosphorlization reaction?
A phosphate is removed
from the ATP and attached to
the molecule needing energy,
thus raising the potential
energy of that molecule.
18. What happens to the
molecule that received the
phosphorus atom during the
phosporization?
The energy amount of the
molecule has
INCREASED. It can now
go on and do its job.
Pops’s Note!
Sucrose?
Sugar
+
Sugar
19. Why is the making of
sucrose considered
ENDERGONIC?
The product (sucrose) has
more energy than the two
reactants:
( glucose + fructose)
20. Write and explain the
exergonic reaction that
supplies the free energy for
the creation of the sucrose
molecule:
Equation:
EXERGONIC:
ATP + glucose
ADP + (glucose-P)
Pop’s note: This reaction
was speeded up to
completion by enzymes.
Explanation
A-P-P-P became A-P-P,
one P bonded with
glucose,thus giving it extra
potential energy.
21. Write and explain the
endergonic reaction tht
results in the creation of the
larger sucrose molecule:
Equation:
ENDERGONIC:
(Glucose-P) + fructose
ADP + P1
Pop’s note: This reaction
was speeded up to
completion by enzymes
Explaination
(Glucose-P) bonded with
fructose. The energy
ENTERED the bonds of the
sucrose and the P1 was free
to rejoin with an ADP to
recreate the ATP molecule.
How ATP is Replenished
22. What common food
molecule is used mainly
for energy?
Glucose (a simple sugar)
23. What is Cellular
respiration?
An exergonic reaction in
which glucose and oxygen
are combined and the
glucose is slowly broken
down.
24. What happens to the
energy tht is released
during cellular respiration?
a)the energy is spread out
among 38 ATP molecules.
b) 2 ATP molecules are
used to power the cell
respiration process. 36
ATP are for net service.
25. What are aerobic
processes?
Any chemical activity that
involves OXYGEN.
26.What is Aerobic
Respiration?
The portion of glucose
breakdown that occurs
inside the mitochondria
using OXYGEN.
27. Where do the first steps
of cell respiration actually
occur?
The first step of Cell
Respiration is called
GLYCOLYSIS, and
occurs in the cytoplasm
while the sugar is on its
way to the mitochondria.
28. Where is cell
respiration completed?
Cell respiration is
completed INSIDE the
mitochondria once the
glucose and oxygen finally
get together.
29. What is the Cytric Acid
Cycle? Where does it take
place?
The cytric acid cycle is a
SERIES of chemical
reactions, resulting in
many intermediates, by
which the glucose is
broken down and the
energy released bit by bit.
Where does it take place?
Inside the folds of the
mitochondria.
30.How many net
molecules of ATP are
produced during the
Cytric acid cycle?
36
31. Describe the
phospholization of ADP into
ATP that occurs during cell
respiration:
All of the “Used” ADP +
P1 molecules are there
waiting to be recharged.
When free energy is
released by the breakdown
of glucose, the P1 rejoins
ADP to reform ATP.
32. Summarize in an
equation the exergonic
cellular respiration reaction:
C6H1206 +6O2 +38ADP
6C02 +6H20 + 38 ATP
.33. Why is ATP considered
to be the Currency of the
cell?
The energy stored in a
molecule of ATP is a
convenient and safe form of
energy storage.
ANAEROBIC
PROCESSES
34. Why do your muscles
become tired and burned
out all of a sudden after a
hard workout?
a)Your muscles are not
receiving enough oxygen
to carry out aerobic
respiration.
b) Instead, your muscles
are doing the best they can
WITHOUT oxygen and
they can’t get much energy
that way.
35. What is the difference
between aerobic respiration
and anaerobic respiration?
Aerobic Respiration occurs
WITH oxygen creates a lot
of ATP.
Anaeorbic Respiration
occurs WITHOUT oxygen
creating very little ATP.
36. In animal cells, where
does anaerobic respiration
occur?
IN THE CYTOPLASM
37. How many ATP
molecules can be created
and used for free energy
using anaerobic
respiration?
2 ATP are created.
LACTIC ACID
FERMENTATION
38. What would cause
Lactic acid fermentation to
occur inside your muscle
cells?
If your muscle cells do not
get enough oxygen for
aerobic respiration to
occur, then lactic acid
fermentation takes over
and does the best it can.
39. What happens when
lactic acid fermentation
occurs in your cells?
Lactic acid builds up in
your cells. The cells burn
really bad until the acid
can get out of the cells.
40. Write the equation that
summarizes the lactic acid
fermentation process
Glucose + 4ADP +4P1
2 lactic acid + 4 ATP
41. What is Alcohol
fermentation? Industry
uses?
An anaerobic process in
which enzymes breakdown
a glucose molecule into 2
molecules of ethanol and
two molecules of carbon
dioxide, transferring
energy to 4 ATP.
Industry Uses?
Beer, wine, liquors
Baking bread
42. Write the equation that
summarizes the alcohol
fermentation reaction:
Glucose + 4 ADP + 4 P1
2 ethanol + 2 CO2 + 4ATP