Transcript Photosynthesis

Photosynthesis
Energy & Life
1
Review of Cellular
Respiration
Glycolysis
2 ATP
Fermentation
Krebs Cycle
36 ATP
6O2 + C6H12O6 = 6CO2 + 6H2O + ATP
Electron Transport Chain
Autotrophs & Heterotrophs
• Autotrophs
• Autotrophs
include
organisms that
make their own
food
• Autotrophs can
use the sun’s
energy directly
• Heterotrophs
• Heterotrophs
are organisms
that can NOT
make their own
food
• Heterotrophs
can NOT
directly use the
sun’s energy
3
Autotroph or Heterotroph?
4
Photosynthesis
• Plants use the energy of sunlight to convert
water and carbon dioxide into high-energy
carbohydrates (glucose) and oxygen, a waste
product.
• Plants and some other types of organisms that
contain chlorophyll are able to use light energy
from the sun to produce food.
• Occurs in chloroplast of most plant cells and
some single celled organisms.
• 6CO2 + 6H20 = C6H12O6 + 6O2
Review ATP
• ATP is the form of energy that is stored
in and used by cells.
• ATP stands for adenosine triphosphate.
• How many phosphates does it have?____
• Energy is released when ATP is converted
to ADP or adenosine diphosphate.
• Can you guess what happened? Tri to di
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ATP to ADP means that one phosphate is removed
As a result, energy is released.
The cell can use this energy for daily activities.
ATP is the basic energy source for all cells.
Releasing Energy From ATP
• Adding A
Phosphate Group
To ADP stores
Energy in ATP
• Removing A
Phosphate Group
From ATP
Releases Energy
& forms ADP
Loose
Gain
8
Glucose
• ATP is used by the cell. They have
only enough energy for a few
seconds.
• It’s not very good for storage
• Glucose is the stored form of
energy. It is a form of sugar stored
by the body.
• When cells need more ATP, they
break down the large glucose
molecule.
Photosynthesis again
• Photosynthesis is when plants use the
energy of the sun to convert water and
carbon dioxide into oxygen and high energy
carbohydrates (sugars and starches).
• The equation:
• Sunlight reaches earth and hits the plant.
• Plants absorb the sunlight with pigments such as
cholorphyll.
• Notice in the equation above that a plant
converts 6 molecules on carbon dioxide at a
time.
• How many carbons does the sugar product
have? ____ Why?___________________
• Plants use this sugar that they created to
produce complex carbohydrates such as
starches.
Where does this entire
process take place?
• Inside a chloroplast.
• Photosynthesis takes place in two
stages
• 1. light dependent stage
• 2. light independent stage (AKA:
Calvin Cycle).
Light dependent stage
The light dependent stages uses sunlight to make
energy.
Sunlight excites the chlorophyll inside the chloroplast
and it makes ATP and NADP, which are both forms
of energy for the cell.
The waste product in this stage is oxygen.
Light Dependent Reaction
• Takes place within the thylakoid membrane.
• The light dependent reactions produce
oxygen gas and convert ADP and NADP+
into energy carriers ATP and NADPH
Calvin Cycle
• The Calvin Cycle is the light
independent stage:
• This means it does not use sunlight.
• When does this stage
occur?__________
• In this stage the ATP made in the
first stage is used to make sugar
with a lot of energy.
The process of the Calvin
Cycle
• Six molecules of carbon
dioxide enter to plant
from the atmosphere.
• ATP is used to make a six
carbon sugar
• Plant uses the sugar for
• A. Energy
• B. to build larger sugar
molecules such as
starches.
Why does the plant make
it’s own sugar?
It uses the energy for growth and
development.
Also, other animals can eat the plant
to use the energy stored within its
carbohydrates (sugars).
Review questions
• Most autotrophs store energy in the form of
1. starches
2. carbon dioxide
3. water
4. nucleic acids
• 7 The largest amount of DNA in a plant cell is
contained in
• (1) a nucleus
• (2) a chromosome
• (3) a protein molecule
• (4) an enzyme molecule
• Which part of a molecule provides energy for life
processes?
• (1) carbon atoms (3) chemical bonds
• (2) oxygen atoms (4) inorganic nitrogen
• The dissolved carbon dioxide in a lake is used
directly by
• (1) autotrophs (3) fungi
• (2) parasites (4) decomposers