Transcript Cellular Respiration - Fulton County Schools

Cellular
Respiration
and
Photosynthesis
ATP
Adenosine Triphosphate
Main energy source for
animal cells
Energy is stored in the
bonds between phosphate
atoms

Give off LOTS of energy when
broken!
ATP
ATP is made from ADP


A new phosphate gets added to ADP to make
ATP
Enzymes catalyze these reactions
ATPase: breaks down ATP
ATP synthase: makes ATP from ADP

The ATP and ADP molecules get reused over
and over again BUT energy does NOT get
reused.
Cell Respiration
Energy stored in glucose is released
through a process called Cell
Respiration. This occurs in all living
organisms.
Two types of Cell Respiration:


Aerobic – requires O2
Anaerobic – Does not require O2
Cellular Respiration
The process of transferring the energy in
carbohydrates into a useable form of
energy for the cell (ATP)
Occurs in the cytoplasm and mitochondria
of Autotrophs and Heterotrophs
C6H12O6 + O2  CO2 + H2O + ATP + Heat
Cellular Respiration
Three phases

Glycolysis
Anaerobic

Citric Acid Cycle (Krebs Cycle)
Aerobic

Electron Transport Chain
Aerobic
Phase I: Glycolysis
Anaerobic: does NOT require O2
Occurs in the cytoplasm
Series of chemical reactions that break
down one glucose into two sugar
molecules
Produces 4 ATP molecules

But it takes 2 to get the reaction started for a
net production of TWO ATP!
Phase II: Citric Acid Cycle
Also known as Krebs Cycle
Aerobic: requires O2
Occurs in the mitochondria
Glucose is broken down even further
Products: 2 ATP and CO2
Phase III: Electron
Transport Chain
Aerobic: requires O2
Occurs in mitochondria inner membrane
Electrons from CAC pass thru a chain of
proteins
Products: 32 ATP and H2O
Fermentation
After glycolysis, if no O2 then fermentation
occurs


Fermentation is an ANAEROBIC process!
Allows cell to continue using glycolysis to
generate ATP
2 kinds of Fermentation


Lactic Acid Fermentation
Alcoholic Fermentation
Fermentation
Lactic Acid Fermentation



In animals and some bacteria
Results in the production of lactic acid
If too much builds up, can result in muscle
soreness
Alcoholic Fermentation


Yeasts, plants
Used in bread and alcohol manufacturing
Fermentation
Lactic Acid Fermentation

Bacteria in a closed container of milk are in an
anaerobic environment so they use
fermentation to make ATP and the lactic acid
produced curdles the milk. This is what
produces cheese, yogurt, sour cream, and
cottage cheese.
Alcoholic Fermentation

Yeasts in bread dough are also in anaerobic
environment. CO2 gas is produced as a by
product and is what makes dough rise.
Alcohol evaporates out of bread during
baking.
32 ATP
Energy Summary
(number of ATP molecules formed in
each step of respiration)
Glycolysis
Kreb’s
cycle
Electron
Transport
Total:
Aerobic
Respiration
2 ATP
Glycolysis
2 ATP
32 ATP
Fermentation
0 ATP
36 ATP
Total:
Anaerobic
Respiration
2 ATP
2 ATP
Photosynthesis
Meaning “making with light”
Photosynthesis is the process of converting the
sun’s light energy into stored carbohydrates
(glucose)
Takes place in in the chloroplasts of
autotrophs
The green pigment chlorophyll is required for
photosynthesis
CO2 + H20 + Light  C6H12O6 + O2
Chemical Reactions
Two phases

Light Dependent Reactions
Turns light energy into ATP

Light Independent Reactions
Conversion of CO2 into Glucose
Light Dependent Reactions
Light energy transfers to electrons in
chlorophyll
Excited electrons pass through a chain
of proteins

electrons loose energy at each step,
creating ATP
H20 is split to replace electrons

Gives off O2
Light Independent Reactions
Also known as the Calvin Cycle

DON’T CONFUSE WITH KREBS CYCLE!!!
Series of reactions that use ATP to
convert CO2 into Glucose
LOTS of enzymes used

That Mrs. Ball is nice enough to NOT make
you know!