Transcript PHOTOSYNTHESIS - Hillsborough County Public Schools

PHOTOSYNTHESIS
CHEMICAL ENERGY AND
ATP
PHOTOSYNTHESIS
• Chemical Energy and ATP
– Burning candles can release energy.
– Chemical bonds are changed from high energy to
low energy releasing heat and light energy.
• One of the principal chemical compounds that cells use
to store and release energy is adenosine triphosphate
or ATP.
– Storing Energy
• Adenosine diphosphate (ADP)
– A compound that is very similar to ATP, except that it has two
phosphate groups instead of three.
PHOTOSYNTHESIS
• This is the way cells store energy.
• When a cell has energy available, it can store small
amounts of it by adding a phosphate group to ADP
molecules, producing ATP.
– Releasing Energy
• How is the energy stored in ATP released?
– The chemical bonds are broken.
– ATP has enough energy to power a variety of cellular activities
transport, including active transport across cell membranes,
protein synthesis, muscle contraction.
• The characteristics of ATP make it exceptionally useful
as the basic energy source of all cells.
ADENOSINE TRIPHOSPHATE
ADENOSINE TRIPHOSPHATE
ADENOSINE TRIPHOSPHATE
ADENOSINE TRIPHOSPHATE
ADENOSINE TRIPHOSPHATE
ADENOSINE TRIPHOSPHATE
ADENOSINE TRIPHOSPHATE
PHOTOSYNTHESIS
• Using Biochemical Energy
– Cells carry out active transport using ATP.
• The sodium- potassium pump is one way.
– Pumps sodium out and potassium in.
• ATP produces movement of motor proteins that move
organelles throughout the cell.
– ATP powers the synthesis of proteins and nucleic
acids (store and transmit hereditary, or genetic
information) and responses to chemical signals at
the cell surface.
PHOTOSYNTHESIS
– Most cells have only a small amount of ATP on
hand.
– They can synthesize ATP from ADP, when needed,
by using energy in foods like glucose.
• The Photosynthesis Equation
– 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
↑
light ↘
carbon dioxide + water → sugars + oxygen
PHOTOSYNTHESIS
– Photosynthesis uses the energy of sunlight to
convert water and carbon dioxide into high
energy sugars and oxygen.
– Plants can convert the sugars into starches.
• Light and Pigments
– How do plants convert the low energy raw
materials into high energy sugars?
– How do plants capture the energy of the sun?
PHOTOSYNTHESIS
PHOTOSYNTHESIS
PHOTOSYNTHESIS
PHOTOSYNTHESIS
– In addition to water and carbon dioxide,
photosynthesis requires light and chlorophyll, a
molecule in chloroplasts.
– Energy from the sun travels to Earth in the form of
light.
• There are different wavelengths of light.
• Some are visible as the visible spectrum and are seen
as colors.
– Plants gather the sun’s energy with light absorbing
molecules called pigments.
PHOTOSYNTHESIS
– Chlorophyll is the principal pigment in the plant.
– Chlorophyll absorbs the light in the blue-violet and
red regions of the spectrum.
– Light is not absorbed well in the green spectrum
and green light is reflected by the leaves, which is
why the plants look green.
– Light is energy and the energy that the chlorophyll
absorbs is used to make photosynthesis work.
PHOTOSYNTHESIS
PHOTOSYNTHESIS
CELLULAR RESPIRATION
• Overview of Cellular Respiration
– Cellular respiration is the process that releases
energy by breaking down glucose and other food
molecules in the presence of oxygen.
– 6O₂ +C₆H₁₂O₆ → 6CO₂ + 6H₂O + Energy
– oxygen + sugar→carbon dioxide+water + energy
– The cells don’t convert and release this energy all
at once. It does it a little bit at a time.
CELL RESPIRATION
COMPARING PHOTOSYNTHESIS AND
CELLULAR RESPIRATION
• The energy flows in photosynthesis and cellular
respiration take place in opposite directions.
– Photosynthesis deposits the energy and cellular
respiration withdraws the energy.
– The equations for each are the reverse of each other.
– Photosynthesis removes carbon dioxide from the
atmosphere and cellular respiration puts it back.
– Photosynthesis releases oxygen and cellular
respirations uses it.
COMPARING PHOTOSYNTHESIS AND
CELLULAR RESPIRATION
• Release of energy by cellular respiration takes place in
all eukaryotes and some prokaryotes.
• Energy capture by photosynthesis takes place only in
plants, algae, and some bacteria.
COMPARING PHOTOSYNTHESIS AND CELLULAR
RESPIRATION
Photosynthesis
Cellular Respiration
Function
Energy capture
Energy release
Location
Chloroplasts
Mitochondria
Reactants
CO₂ and H₂O
C₆H₁₂O₆ and O₂
Products
C₆H₁₂O₆ and O₂
CO₂ and H₂O
Equation
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
6O₂ + C₆H₁₂O₆ → 6CO₂ + 6 H₂O