BIOLOGY 111
CHAPTER 4: The Plant Cell
Life’s Home
Life's Home:
The Cell as a Factory

Review:
Life's Home: THE CELL
4.1 Cells as Life's Fundamental Unit
4.2 Prokaryotic and Eukaryotic Cells
4.3 The Eukaryotic Cell
4.4 A Tour of the Animal Cell's Protein Production Path
4.5 Cell Structures Outside the Protein Production Path
4.6 The Cytoskeleton: Internal Scaffolding
4.7 The Plant Cell
THE PLANT CELL
• Plants are Eukaryotic organisms
• Similarities Between Plant and Animal Cells:
• Most of the organelles found in animal cells are also found in
plant cells.
Comparing Animal and Plant Cells
• Plants are Eukaryotic organisms
• Differences Between Plant and Animal Cells:
• Only in Animal Cells –
• Lysosomes
• Only in Plant Cells –
• Chloroplasts
• Central Vacuole
• Cell walls
Comparing Animal and Plant Cells
• Plants are Eukaryotic organisms
• Differences Between Plant and Animal Cells:
Comparing Animal and Plant Cells
CHLOROPLAST
Comparing Animal and Plant Cells
CHLOROPLAST
THE PLANT CELL
CHLOROPLAST
• Organelle
• Location for
photosynthesis in plants
• Absorb light energy and
transform it into
chemical energy in
molecules of Glucose
THE PLANT CELL
CELL WALL
• Provides structure
for the plant cell
• Composed of
polysaccharides
(cellulose) and
proteins
THE PLANT CELL
CELL WALL
• Provides structure
for the plant cell
• Composed of
polysaccharides
(cellulose) and
proteins
THE PLANT CELL
CENTRAL VACUOLE
Used to breakdown
cellular components
and for storage
THE PLANT CELL
• Plants are Eukaryotic organisms
• Differences Between Plant and Animal Cells:
• Only in Animal Cells –
• Lysosomes
• Only in Plant Cells –
• Central Vacuole
• Chloroplasts
• Cell walls
BIOLOGY 111
CHAPTER 8: The Green World’s Gift
Photosynthesis
The Green World’s Gift:
Photosynthesis
•
•
•
•
8.1 Photosynthesis and Energy
8.2 The Components of Photosynthesis
8.3 Stage 1: The Light Reactions
8.4 Stage 2: The Calvin Cycle
Photosynthesis
•
Bringing Useful Energy to Living Things
•
Most of the living world ultimately depends on photosynthesis to get
energy from food. – Glucose!
•
Much of the living world depends on photosynthesis for a waste
product of the reaction – Oxygen
•
Photosynthesis occurs in plants, algae and Cyanobacteria
Photosynthesis
The Balance Between Photosynthesis and Cellular Respiration
Respiration:
Takes high energy electrons from glucose and dumps them onto O2 ,
forming H2O. Producing ATP (Exergonic)
Photosynthesis:
Uses sunlight to take electrons back from H20, Energize them and
pushes them into Glucose (Endergonic)
Photosynthesis
The Balance Between Photosynthesis and Cellular Respiration
Products from
photosynthesis
are used for
respiration
Products from
respiration are
used for
photosynthesis
Photosynthesis
The Balance Between Photosynthesis and Cellular Respiration
Photosynthesis and Cellular Respiration are different directions of the
same chemical reactionPhotosynthesis captures energy (sunlight = endergonic)
Respiration releases energy ( ATP = exergonic)
The Green World’s Gift:
Photosynthesis
•
•
•
•
8.1 Photosynthesis and Energy
8.2 The Components of Photosynthesis
8.3 Stage 1: The Light Reactions
8.4 Stage 2: The Calvin Cycle
Photosynthesis: Capturing the Sun’s Energy
What is the least
important color to most
plants?
GREEN!
Green light is not
absorbed by most
plants and is instead
reflected – making
plants appear green.
Photosynthesis: Capturing the Sun’s Energy
Plants primarily absorb
blue and red
wavelengths of light
Pigments, like
Chlorophyll, absorb
and trap the blue and
red wavelengths of
visible light
Photosynthesis:
Where does photosynthesis occur in
leaves?
Photosynthesis occurs in the mesophyll
cells of leaves
Mesophyll cells contain Chloroplasts
Chloroplasts contain stacks (Granum)
and a water filled area called Stroma
Photosynthesis:
Where does photosynthesis occur in
leaves?
Stomata are pores in leaves that open
to let CO2 in and H2O out.
The Green World’s Gift:
Photosynthesis
•
•
•
•
8.1 Photosynthesis and Energy
8.2 The Components of Photosynthesis
8.3 Stage 1: The Light Reactions
8.4 Stage 2: The Calvin Cycle
Photosynthesis
Two stages of photosynthesis
Light Reactions:
This is the ‘Photo’ part of photosynthesis
Light energy is captured in electrons
The Calvin Cycle:
This is the ‘synthesis’ part of photosynthesis
Energized electrons are built into Glucose
Photosynthesis
First stage of photosynthesis
Light Reactions:
This is the ‘Photo’ part of photosynthesis
1)
2)
3)
4)
Light energy is captured by a pigment, Chlorophyll
This energy strips electrons from H2O (releasing Oxygen)
These electrons are charged to an “excited” energy state
Electrons go to a carrier molecule (similar to NADH)
Photosynthesis
First stage of photosynthesis
Light Reactions:
This is the ‘Photo’ part of photosynthesis
1)
2)
3)
4)
Light energy is captured by a pigment, Chlorophyll
This energy strips electrons from H2O (releasing Oxygen)
These electrons are charged to an “excited” energy state
Electrons go to a carrier molecule for electrons (NADP to NADPH)
* This stage also produces a small amount of ATP
Photosynthesis
First stage of photosynthesis
Light Reaction:
This is the ‘Photo’ part of
photosynthesis
Products = Excited
electrons in NADPH, ATP
and Oxygen
Photosynthesis
Second stage of photosynthesis
Calvin Cycle:
This is the ‘Synthesis’ part of photosynthesis
1)
2)
3)
4)
CO2 enters the leaf through stomata
Excited electrons (NADPH) and ATP used to power ‘Carbon Fixation’
Carbon Fixation:
When Carbon goes from gas (CO2) to a carbohydrate
Rubisco (enzyme) adds CO2 to a low energy sugar (RuBP)
Glucose is produced
Photosynthesis
Second stage of photosynthesis
Calvin Cycle:
This is the ‘Synthesis’ part of
photosynthesis
Starts with produces from
Light Reactions
Products = Glucose (and
other sugars)
Photosynthesis
Summary of Light Reactions and Calvin Cycle
Summary of Photosynthesis
The energy acquired in the light reactions takes two forms: energetic
electrons stored in the carrier NADPH and energy stored in the energy
transfer molecule ATP. An important by-product of the light reactions is
the O2 produced when water is split
Summary of Photosynthesis
Photosynthesis can be divided into two major sets of steps. In the first
set, known as the Light Reactions, absorbed solar energy moves
electrons derived from water in two ways: (a) physically to a molecule
called a NADPH and (b) metaphorically to a higher Energy State.
Summary of Photosynthesis