cellular respiration · photosynthesis •the sun is the main source of energy for life. •the...
Post on 09-Aug-2020
5 Views
Preview:
TRANSCRIPT
CELLULAR RESPIRATION CELLS AS THE BASIS OF LIFE
Eukaryotic Cell Organisation
PLANT CELL ANIMAL CELL
All Cells Require Energy
• All living cells use energy for movement, synthesis
and maintenance of a stable intracellular
environment.
• Law of Conservation of Energy: energy cannot
be created or destroyed, but simply changed from
one form to another
• Forms of energy: light, heat, chemical, kinetic
Living cells must be able to convert chemical
energy into other forms of energy which are more
useful to the cell
Photosynthesis
• The sun is the main source of energy for life.
• The process of converting light energy into
chemical energy is called photosynthesis.
carbon dioxide + water glucose + oxygen
6CO2 + 6H2O C6H12O6 + 6O2
light
chlorophyll
light
chlorophyll
Photosynthesis
• Photosynthesis occurs in the chloroplasts
– Chloroplasts contain the green pigment chlorophyll
– Light energy is trapped by chlorophyll
Photosynthesis
• Chloroplasts are found in cells called mesophyll cells which
are found in the leaves.
Photosynthesis
• Stomata are located on the under side of a leaf. They consist of
two guard cells surrounding a small pore.
• The guard cells have a very thick cell wall. Water is able to move in
and out of the guard cells, causing them to change shape.
– Turgid (swollen) guard cells = stomata open
– Flaccid (shrunken) guard cells = stomata close
Photosynthesis
FLACCID GUARD CELLS
• Occurs during times of water stress (limited availability or in
warmer air temperatures)
• Causes stomata to close
• Generally occurs during the day
• Reduces water loss
• Oxygen and carbon dioxide does not diffuse into and out of
the leaf
TURGID GUARD CELLS
• Occurs when water is available (particularly in cooler air
temperatures)
• Causes stomata to open
• Generally occurs during the night
• Oxygen and carbon dioxide readily diffuse into and out of
the leaf
Photosynthesis
During the night, cooler
air temperatures
(moisture in the air)
allow guard cells to
swell, opening the
stomata
Open stomata allow
carbon dioxide in the air
to enter the leaf and
oxygen (produced by
photosynthesis) to exit
the leaf During the day, warmer
air temperatures (less
moisture in the air)
cause guard cells to
become flaccid, closing
the stomata
Sunlight shining on the
leaves gets captured by
the green pigment
chlorophyll (found in
the chloroplasts)
The captured energy
allows carbon dioxide
and water to combine
to form glucose and
oxygen
Cellular Respiration
• Photosynthesis involves converting light energy
into chemical energy (in the form of glucose).
• The chemical energy must then be
transformed into a useable form of energy.
carbon dioxide + water glucose + oxygen
6CO2 + 6H2O C6H12O6 + 6O2
light
chlorophyll
light
chlorophyll
Cellular Respiration
• Energy is stored in chemical bonds between atoms in
molecules. The more chemical bonds, the more energy
that the molecule contains.
BREAKING BONDS Energy is released
MAKING BONDS Energy is required
Cellular Respiration
• Glucose is a complex macromolecule that
contains many bonds. These bonds can be
broken to create smaller molecules with less
energy.
• This processes is called cellular respiration.
• As large molecules are broken down into small
molecules some of the stored chemical energy is
converted to energy in chemical bonds of a
small molecule called ATP and the rest is
released as heat.
ATP, ADP and Pi
• ATP = adenosine tri-phosphate
• ATP is the cell’s immediate source of energy. It
is used for almost every energy-requiring
reaction in a cell
ADENINE BASE
5-CARBON
(PENTOSE) SUGAR
THREE
PHOSPHATE
GROUPS
ATP, ADP and Pi
• ATP = adenosine tri-phosphate
• ATP is the cell’s immediate source of energy. It
is used for almost every energy-requiring
reaction in a cell
ADENINE BASE
5-CARBON
(PENTOSE) SUGAR
THREE
PHOSPHATE
GROUPS
This bond can be easily
broken to release free
energy
ATP, ADP and Pi
• When the weak phosphate bond is broken, ATP
is converted to ADP (adenosine di-phosphate)
and phosphate. Free energy becomes available.
+
ATP ADP PHOSPHATE
ATP, ADP and Pi
• Cells use ATP continuously, however ATP stores
can be regenerated when energy from
respiration reactions is used to reform ATP from
ADP and phosphate.
ATP, ADP and Pi
BREAKING BONDS Energy is released
MAKING BONDS Energy is required
ATP ADP + P ATP ADP + P
Aerobic Respiration
Glucose C6H12O6
(from photosynthesis)
Aerobic Respiration
Glycolysis
↓
Citric Acid Cycle
↓
Electron Transport Chain
Anaerobic Respiration
Glycolysis
↓
Fermentation
… is broken down to release energy via …
Aerobic Respiration
• The food we eat reacts with the air we breathe to
produce smaller molecules and energy which is
needed for life.
• Cells extract energy from glucose by breaking
bonds between the carbon atoms, producing
ATP.
Aerobic respiration ONLY occurs in the
presence of oxygen
glucose + oxygen carbon dioxide + water + energy
C6H12O6 + 6O2 6CO2 + 6H2O + energy
Glycolysis
• Glucose (6 carbons) is broken in half forming
two, 3 carbon molecules called pyruvate.
• Occurs in the cytoplasm of cells.
• 2 ATP molecules are produced.
PYRUVATE
(3 carbons)
GLUCOSE
(6 carbons)
2 x ATP
Citric Acid Cycle
• Pyruvate moves to the mitochondrial matrix,
which is where the citric acid cycle occurs.
• The carbon bonds in pyruvate are broken,
forming new, small energy carriers as products.
PYRUVATE
(3 carbons)
CARBON DIOXIDE (waste product)
NEW SMALL
ENERGY CARRIERS
CITRIC ACID
CYCLE
Electron Transport Chain
• The electron transport chain is located in the
mitochondria inner membrane.
• It is simply a chain reaction of events that leads
to the production of ATP.
• The small energy carrier products from the citric
acid cycle power the electron transport chain.
• 36 ATP molecules are produced
WATER (from O2 and H+)
NEW SMALL
ENERGY CARRIERS
(from citric acid cycle)
ELECTRON TRANSPORT
CHAIN
36 x ATP
Aerobic Respiration Summary
C6H12O6 + 6O2 6CO2 + 6H2O + 38 ATP
GLYCOLYSIS
Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
CITRIC ACID CYCLE
Pyruvate is broken down to produce carbon dioxide and new small
energy carriers.
ELECTRON TRANSPORT CHAIN
Small energy carriers (from Citric Acid Cycle) power the electron
transport chain to produce 36 ATP molecules and water.
Aerobic Respiration Summary
C6H12O6 + 6O2 6CO2 + 6H2O + 38 ATP
GLYCOLYSIS
Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
CITRIC ACID CYCLE
Pyruvate is broken down to produce carbon dioxide and new small
energy carriers.
ELECTRON TRANSPORT CHAIN
Small energy carriers (from Citric Acid Cycle) power the electron
transport chain to produce 36 ATP molecules and water.
Aerobic Respiration Summary
C6H12O6 + 6O2 6CO2 + 6H2O + 38 ATP
GLYCOLYSIS
Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
CITRIC ACID CYCLE
Pyruvate is broken down to produce carbon dioxide and new small
energy carriers.
ELECTRON TRANSPORT CHAIN
Small energy carriers (from Citric Acid Cycle) power the electron
transport chain to produce 36 ATP molecules and water.
Aerobic Respiration Summary
C6H12O6 + 6O2 6CO2 + 6H2O + 38 ATP
GLYCOLYSIS
Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
CITRIC ACID CYCLE
Pyruvate is broken down to produce carbon dioxide and new small
energy carriers.
ELECTRON TRANSPORT CHAIN
Small energy carriers (from Citric Acid Cycle) power the electron
transport chain to produce 36 ATP molecules and water.
Aerobic Respiration Summary
C6H12O6 + 6O2 6CO2 + 6H2O + 38 ATP
GLYCOLYSIS
Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
CITRIC ACID CYCLE
Pyruvate is broken down to produce carbon dioxide and new small
energy carriers.
ELECTRON TRANSPORT CHAIN
Small energy carriers (from Citric Acid Cycle) power the electron
transport chain to produce 36 ATP molecules and water.
Aerobic Respiration Summary
C6H12O6 + 6O2 6CO2 + 6H2O + 38 ATP
GLYCOLYSIS
Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
CITRIC ACID CYCLE
Pyruvate is broken down to produce carbon dioxide and new small
energy carriers.
ELECTRON TRANSPORT CHAIN
Small energy carriers (from Citric Acid Cycle) power the electron
transport chain to produce 36 ATP molecules and water.
Cellular Respiration
Glucose C6H12O6
(from photosynthesis)
Aerobic Respiration
Glycolysis
↓
Citric Acid Cycle
↓
Electron Transport Chain
Anaerobic Respiration
Glycolysis
↓
Fermentation
Broken down to release energy via …
Anaerobic Respiration
• When oxygen is NOT available, conditions are
considered ‘anaerobic’.
• In the absence of oxygen, glucose is only partly
broken down, the molecules produced are larger
and there will be less energy available to the cell.
• The first step is glycolysis. Since glycolysis does
not require oxygen, is occurs the same as it does
for aerobic respiration
Fermentation
Plants and Yeast
glucose ethanol + carbon dioxide + energy
C6H12O6 2C2H5OH + 2CO2 + energy
Animals
glucose lactic acid + energy
C6H12O6 2C3H6O3 + energy
Fermentation – Plants and Yeast
• In the absence of oxygen, plants and yeast
undergo fermentation to form ethanol and
carbon dioxide.
• 2 ATP molecules are formed during glycolysis
PYRUVATE
(from glycolysis)
CARBON DIOXIDE (waste product)
ETHANOL
FERMENTATION
Fermentation – Animals
• In the absence of oxygen, animals undergo
fermentation to form lactic acid.
• 2 ATP molecules are formed during glycolysis
PYRUVATE
(from glycolysis) LACTIC ACID
FERMENTATION
Anaerobic Respiration Summary
PLANTS AND YEAST
C6H12O6 2C2H5OH + 2CO2 + 2 ATP
GLYCOLYSIS Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
FERMENTATION Pyruvate is broken down to produce ethanol and carbon dioxide.
Anaerobic Respiration Summary
PLANTS AND YEAST
C6H12O6 2C2H5OH + 2CO2 + 2 ATP
GLYCOLYSIS Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
FERMENTATION Pyruvate is broken down to produce ethanol and carbon dioxide.
Anaerobic Respiration Summary
PLANTS AND YEAST
C6H12O6 2C2H5OH + 2CO2 + 2 ATP
GLYCOLYSIS Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
FERMENTATION Pyruvate is broken down to produce ethanol and carbon dioxide.
Anaerobic Respiration Summary
PLANTS AND YEAST
C6H12O6 2C2H5OH + 2CO2 + 2 ATP
GLYCOLYSIS Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
FERMENTATION Pyruvate is broken down to produce ethanol and carbon dioxide.
Anaerobic Respiration Summary
ANIMALS
C6H12O6 2C3H6O3 + 2 ATP
GLYCOLYSIS Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
FERMENTATION Pyruvate is broken down to produce lactic acid.
Anaerobic Respiration Summary
ANIMALS
C6H12O6 2C3H6O3 + 2 ATP
GLYCOLYSIS Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
FERMENTATION Pyruvate is broken down to produce lactic acid.
Anaerobic Respiration Summary
ANIMALS
C6H12O6 2C3H6O3 + 2 ATP
GLYCOLYSIS Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
FERMENTATION Pyruvate is broken down to produce lactic acid.
Anaerobic Respiration Summary
ANIMALS
C6H12O6 2C3H6O3 + 2 ATP
GLYCOLYSIS Glucose (from photosynthesis) is broken down into 2x pyruvate.
2 ATP molecules produced.
FERMENTATION Pyruvate is broken down to produce lactic acid.
Cellular Respiration Summary
PHOTOSYNTHESIS Production of glucose
AEROBIC RESPIRATION
GLYCOLYSIS Glucose → Pyruvate
CITRIC ACID CYCLE Production of carbon dioxide
and new small energy carriers
ELECTON TRANSPORT CHAIN Production of ATP and water
FERMENTATION Plants/Yeast –
Production of ethanol
and carbon dioxide
FERMENTATION Animals – production
of lactic acid
ANAEROBIC RESPIRATION
2 x ATP
36 x ATP
top related