Transcript Plants and Photosynthesis

Photosynthesis
What is Photosynthesis?
It’s a PROCESS!
Plants, green algae and some bacteria can make
their own food through a process called
Photosynthesis
Photosynthesis converts the energy from the
sun into the MOST IMPORTANT organic food
molecule!
So, Inorganic molecules are changed into
organic glucose
So?
• What ORGANELLES do plant cells have that
WE DO NOT?
_____________ & _______________
• What is THE MOST IMPORTANT organic food
molecule?
___________________
• What’s the formula?
___________________
Chloroplasts…
• What happens in the Chloroplast?
______________________________
• For what reason do ALL living organisms need
Glucose?
______________________________
• Do WE have Chloroplasts? ___________
• Can WE make our own food? _________
• How do WE get the Glucose we need?
______________________________
Basic Photosynthesis
• There are
certain raw
materials
(reactants) the
plant needs to
start with...
Let's take a guess
What do plants NEED to survive?
__________ & __________ & ________
What do plants MAKE that EVERY LIVING
ORGANISM NEEDS?
______________
Things needed for photosynthesis
SUNLIGHT
Gives the plant energy
WATER
Travels up
from the roots
CARBON DIOXIDE
Enters the leaf through pores
(stomates) on the underside
CHLOROPHYLL
The green
pigment
where the
chemical
reactions
happen
Photosynthesis equations
Carbon dioxide + water
CO2
+ H20
Sunlight
Chlorophyll
Sunlight
Chlorophyll
glucose + oxygen
C6H12O6 + O2
The GLUCOSE produced by photosynthesis is used by
the plant for energy!
The plant stores extra glucose as cellulose (starch).
Where is cellulose “stored”? _______________
Close up of a plant cell:
Cell
wall
Cell
membrane
Large
vacuole
Chloroplasts
(containing
chlorophyll)
Nucleus
Cytoplasm
Photosynthesis happens in the
chloroplasts (in the upper part of
the leaf)
Chloroplasts
Let's talk about leaves...
• Leaves are built in a very specific way.
• Leaves have STOMATES (stoma, stomata)
which are pores in the bottom surface of a
plant leaf.
• Gases (CO2 & O2) pass through the pores.
• Stomates open and close to control gas and
water loss (transpiration).
• The amount that the Stomate is “allowed” to
open is controlled by Guard Cells.
Plant Leaf Anatomy
Plant Leaf Anatomy:
Getting CO2 & Sunlight
Top
Layer
Bottom
Side
Stomates and Guard Cells
• Each Stoma is “guarded” by two guard cells.
• Guard cells are long, water-filled cells on each
side of the opening.
Stomates & Guard Cells
• When they swell with water, Guard Cells close
the opening of the stoma and reduce water
loss (transpiration).
• When sunlight hits the leaves, the guard cells
release the water they absorbed at night.
• They shrink, the opening becomes wider, and
water / oxygen are released and carbon
dioxide is taken in...
–
So Photosynthesis Can Begin!
Chloroplasts
• Site of
Photosynthesis
• Where sunlight,
CO2 and H2O are
converted to
C6H12O6
• What is C6H12O6?
Capturing the Light
• The Chlorophyll pigment in the Chloroplasts,
absorbs and traps solar energy
- Think of a bouncy ball!
Chlorophyll works with plant enzymes to
change this solar (aka Radiant Energy) into
glucose (Chemical Energy)
Glucose (Chemical Energy) is the “usable”
form of energy for all living things!
Quick Questions
• Why do you think the stoma (pores) are
mostly located on the underside of the plant
leaf?
• Why do you think the chloroplasts are mostly
located on the upper side of the plant leaf?
Leaf Anatomy Vocabulary
Cuticle: Waxy coating on the leaf of the plant. This
stops water from evaporating.
Chloroplast: Organelle responsible for Photosynthesis.
Chlorophyll: Green pigment in Chloroplast that absorbs
solar energy.
Stomates: Openings (pores) in the underside of the
leaf which allow gas exchange.
Guard Cells: Surround the stomate and control gas and
water loss (transpiration).
Veins: Carry water from roots (xylem) and glucose from
leaves (phloem) to other parts of plant.
Storing Energy
• ALL ENERGY FOR LIFE COMES FROM THE
SUN!
• All living organisms can NOT perform
Photosynthesis (we surely can't!)
• BUT...Photosynthesis allows ALL living
organisms to use the sun's energy to
remain alive... how does THAT work?
Converting the Energy
• In the Chloroplasts, the energy from the sun is
used to break apart CO2 and H2O
–
What Reaction breaks bonds using water?
– _____________________________________
• These Carbon, Hydrogen & Oxygen atoms are
rearranged to make C6H12O6 (Glucose)
–
What Reaction uses water to make/build
something more complex?
– ____________________________________
“Food” = Nutrition
• Sooo... plants, green algae and some bacteria
can make their own food!
• They are called Autotrophs
•
Auto=self
•
Troph=nourishment
• Animals cannot make their own food and
must get our glucose from plants.
• Animals are called Heterotrophs
•
Hetero=other
Regents Image
• What is this process? _____________
What else is made?
(And why is it important?)
• During Photosynthesis, Oxygen gas is also
formed (as a “bi-product”).
• Oxygen is released into the environment
through the stoma...
What happens next?
• What happens to the glucose and oxygen
produced in photosynthesis?
• Plants AND Animals need energy to perform
cellular activities.
• What are the cellular activities? STRANGER-C
• In a process called Cell Respiration, Plants AND
Animals use glucose to create an energy
molecule called ATP.