Autotrophic Nutrition
Living Things Making Their
Own Food
All Living Things Require
Nutrition
• Nutrition is …. Means
of acquiring and
using raw materials
needed for Life
Processes
• Two Categories of
Nutrition:
– Heterotrophic
– Autotrophic
• Heterotrophic Nutrition
“Eating Others”
– Ingesting food (taking-in
other living things)
• Herbivores, Omnivores,
Carnivores, Saprophytes
• Autotrophic Nutrition
“Self-Feeding”
• Make their own food
– Chemotrophs
– Phototrophs
Ancient
Autotrophs:Chemotrophs
• Chemotrophs Use Energy produced during
Chemical Reactions to change inorganic
molecules into Organic Molecules
Chemotrophs (Bacteria) are the most ancient life forms on earth;
they are extremely important to the recycling of organic matter in
food webs
Other Autotrophs
Protist
• Phototrophs absorb
– Light energy to
change inorganic
molecules into Organic
Nutrients
• Some Bacteria
• Green Algae (Protists)
• Green Plants
Algae
Light : part of the Electromagnetic
Spectrum we can SEE
• Made up of particles called photons.
• Travel in waves, having different lengths
• The energy a wave has depends on its
length
• The shorter the wave’s length; the
greater its energy (indirect)
• Each wavelength is seen as a different
color
Visible Light Spectrum
appears white
• “white light” is really a mixture of different
colored waves of electromagnetic energy
Shortest
Longest
ROYGBIV
Chlorophyll: Green Pigment
•
•
•
•
Give green plants and algae their Color
Dominant Plant Pigment
Absorbs Red and Blue Wavelengths
Reflects Green and Yellow Wavelengths
– Plants appear green because they reflect the
green wavelength
– Chlorophyll (a & b) are the light absorbing
pigments of photosynthesis
– Carotenoids other plant pigments
Pigments and Photosynthesis
• Absorption Spectrum
How do we “read” this kind of graph?
Blue-violet colored
wavelength
Hint: The “peaks”
are wavelength
T colors absorbed
h by the pigment;
e the ones used for
photosynthesis
Red colored wavelengths
Chloroplasts: "food factory
Organelles”
• Chloroplasts
Chloroplasts contain the
Green Chlorophyll Pigment
Chloroplasts contained in
plant/algae cells
Photosynthetic algae have chloroplasts
Leaves: Nature’s “Solar
Collectors”
• Leaves are
adaptations for
photosynthesis
– Collect maximum
amount of Sunlight
– Cells contain
chloroplasts
– Can regulate water
and gases entering
and leaving
Leaf Cross-section
Photosynthesis
“to make with light”
Light Energy
6
6 H2O -------------C6H12O6 +__O
• 6__CO2 +__
2
Chlorophyll
Carbon
Dioxide
Water
Glucose
Oxygen
Guard Cells Regulate Gases
Entering and Leaving Leaves
• Guard cells change stoma openings
Guard cells located underside of leaf
Guard Cells
• Guard cells respond to water available to
the plant
Guard
cell
Guard cell
Stoma opening
Function of Guard Cells
Guard cells
Guard cells
CO2
Inner cell
wall
Inner cell
wall
Stoma
O2
Stoma Open
When water is plentiful stoma
Opens to allow Carbon dioxide
To enter and Oxygen to leave
Stoma Closed
When conditions are dry &
Water is scarce, stoma close
To conserve water
Water Movement in Plants
Excess Water Leaves through leaf Stoma
Water Enters through
Roots
Photosynthesis and Chloroplast
Light Energy
Stroma
Grana
Chloroplast
CO2 + H2O
Sugars + O2
(Glucose)
Stages of Photosynthesis
(1st) Light-dependent
Reactions occur in grana
CO2
Light
NADP+
ADP + P
Chloroplast
LightDependent
Reactions
Calvin
Cycle
ATP
NADPH
O2
:
Chloroplast
Sugars
(2nd) Light-independent
Can happen in light
Or Dark
Photosynthesis: Two Stages
• Light Dependent:
• Photolysis
• Occurs in Grana
– Chlorophyll absorbs light
energy; gets really
excited
– Water molecule splits into
H and O2; the O2 enters
atmosphere, the H is
picked-up by NADP
NADPH2
– ADP + P
ATP
• Light-Independent
• Calvin Cycle (“carbon
fixing”)
• Occurs in Stroma
– NADPH2 + CO2 + ATP
Glucose
C6H12O6
Carbon-Fixation or The Calvin
Cycle in “detail”
CO2 Enters the Cycle
Energy Input
ChloropIast
5-Carbon
Molecules
Regenerated
6-Carbon Sugar
Produced
Sugars and other compounds
:
The CO2 entering joins
With the Hydrogens to
Sugar molecules
Concept Map
Section 8-3
Photosynthesis
includes
Lightdependent
reactions
Calvin cycle
use
take place in
Energy from
sunlight
Thylakoid
membranes
to produce
ATP
Go to
Section:
NADPH
O2
takes place in
Stroma
uses
ATP
NADPH
of
to produce
Chloroplasts
High-energy
sugars
Limiting Factors Affecting
Photosynthesis
• Amount of Light
– Greater the duration and
intensity; greater the rate of
photosynthesis
– Will reach maximum then
levels off
• Amount of Water
– Photosynthesis requires
water; less water will
decrease photosynthesis
• Temperature
– Extreme High or Low
temperatures destroy the
enzymes needed for
photosynthesis
• Carbon dioxide
– Not a limiting factor for land
plants
– Is a limiting factor for
aquatic plants
Other limiting factors are soil minerals, Magnesium found in chlorophyll molecule