Cell Energy and Enzymes
Cell Metabolism
 Metabolism
chemical processes
The ________________occurring
within a living
cell
 Necessary for maintaining life
enzymes
 Uses_______________
 Break down or build material the cell needs

Cell Metabolism

Enzymes
proteins
 Are _____________
Required for every chemical reaction in an
organism
 Without, would not be able to maintain
homeostasis
_______________
 They do not make the reaction happen that
couldn’t happen on its own; they simply make
faster
the reaction occur much _________

Cell Metabolism

Function of Enzymes
catalysts
 Serve as ____________
activation energy Work by lowering the ________________
energy required to get the reaction started
Cell Metabolism

Characteristics of Enzymes
pH & temperature
 Work best in a narrow _______________
range
 They are not changed or used up in the
used over & over
reaction; can be __________________
again
 They are substrate-specific; Because of their
shape
enzyme binds to
Substrate- is what the __________________
 Substrate fits into a portion of the enzyme; where
active site
they meet is the ______________

Cell Energy



ability to do work
Energy is the _________________
We & other organism obtain energy from
heterotrophs
food; called ________________
Plants & other organism obtain energy
autotrophs
from the sun; called ______________
photosynthesis
 Process called ________________,
occurs in the chloroplasts
______________________
The equation for photosynthesis:
energy →C6_________+____
CO2
H2O + ______
H12 O6 O2
____+ _____

Cell Energy
A. Chemical Energy
 Stored in chemical
bonds
Potential
 _________energy
When bonds are broken; converted to
_______________
in the form of ______
useable
energy
ATP
cannot be used directly
 Food molecules ________________


The amount of energy released would be
destructive
_________
wasteful and ________
Cell Energy
B. ATP- Adenosine Triphosphate
 ___________
Nucleotide composed of:
Nitrogen base- adenine
_________
5-carbon sugar- ribose
 ________
 ___
3 phosphate groups

Cell Energy
phosphate – phosphate
Energy is stored in ______________________
bonds
__________.
• ATP works like a rechargeable battery.
• Cells are able to use and recycle ATP by
phosphate group
breaking off or adding a ___________
released when phosphate bond is broken &
 Energy ____________
•
ATP is converted to ADP- adenosine diphosphate


uncharged battery
ADP is like an “___________”

recharged like a fully charged rechargeable
ATP is “_____________”
battery
Energy ___________when
phosphate bond is added to ADP
stored
making ATP
Cell Energy
Aerobic
C. Cellular Respiration ___________
Energy Production
 Cellular respiration
Breakdown of _______
glucose in presence of _______
oxygen
ATP
 To make ________
eukaryotic
 Occurs in _________
mitochondria of ___________ cells
 Equation for cellular respiration


_______________________________________
C6 H12 O6 + O2 → CO2 + H2O + energy (ATP)
Cellular Respiration
2
+
2
34
Cell Energy

Steps in making ATP
1. Glycolysis
glucose
one
____molecule
of ________is
broken in half
3 carbon molecule)
 pyruvic acid is formed (________
 occurs in the___________
cytoplasm
2
 produces ___
ATP’s
mitochondria
 Pyruvic acid enters ______________ for next
step in CR

Cell Energy
2. Krebs Cycle
•
•
•
Pyruvic acid is broken down in a
citric acid
series of reactions into __________
Carbon dioxide formed as waste
____________
product
2
Produces ___
ATP’s
Cell Energy
3. Electron Transport Chain


High energy
____________electrons
from the Krebs Cycle are
converted to ATP
___________
must be present at the end of chain to
Oxygen
accept electron
 Forms _________
water
stops
stops ; Krebs ______
 If oxygen is not present ETC______
Produces on average 34 ATPs
TOTAL ATP GAIN IN CELLULAR
36 ATP
RESPIRATION = ________
per MOLECULE OF GLUCOSE
__________________________
Electron Transport Chain
Cell Energy
Anaerobic Energy
D. Fermentation - ________
Production
oxygen is not
 Occurs if _________________
available
Glycolysis
 __________
still takes place
 ___
ATP’s are made for one glucose
2
Cell Energy

2 types of Fermentation
1. Lactic Acid Fermentation:

Muscle
Human _________
Cells
oxygen
Occurs when muscles run out of __________
 Muscle switches to fermentation
pain, soreness &
 Lactic acid builds up; causes _____________
fatigue
_________
 Will switch back to CR when _________
oxygen is resupplied
 Lactic acid is sent to ______
liver to be broken down

•
Bacteria
some bacteria
 during __________
anaerobic conditions
yogurt &
 Utilized by dairy industry to produce _________
cheese
__________

Cell Energy
2. Alcoholic Fermentation


Occurs in ________
Yeast during ___________
anaerobic conditions
Important in ___________________
brewing & baking industries
**TOTAL ATP GAIN IN FERMENTATION =
2 ATP per MOLECULE OF GLUCOSE
_________________________________**