Lesson 3 - The Process of Photosynthesis Flashcards
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From the Greek words
____ - produced by light
____ - a whole made of parts put together
Introduction to Photosynthesis
PHOTO, SYNTHESIS
is the process whereby plants, algae, some bacteria, use the energy of the sun to synthesize organic compounds (sugars) from inorganic compounds (CO2 and water).
- the most important biological process on earth!
- Low Efficiency, 1-4 % in C-3 Plants
Photosynthesis
Why is Photosynthesis Important?
Five reasons
PHOTOSYNTHESIS is one of the most
important biological process on earth!
- Provides the oxygen we breathe
- Consumes much of the CO2
- Food
- Energy
- Fibers and materials
General Formula for Photosynthesis
6 CO2 + 12 H2O —–⚡—-> C6H12O6 + 6 O2 + 6 H2O
Formula for Respiration
C6H12O6 + O2 🡪 6 CO2 + ATP
The primary pigment for photosynthesis is
____, It absorbs ____ and ____ light, not ____
( ____ light is reflected back!)
Light is absorbed by pigments
- Chlorophyll a
- Blue and Red
- Not Green
- Green Light
Accessory pigments like ____ and ____ (beta-carotene, lycopene):
- absorb light at ____ wavelengths,
(extending the absorption range) - help transfer some energy to ____
- protect ____ from harmful byproducts
- Chlorophyll b and Carotenoids
- Different Wavelengths
- Chlorophyll a
- Cell
is the primary photosynthetic pigment that drives photosynthesis.
Chlorophyll a
____ absorb at different wavelengths, extending the range of light useful for photosynthesis.
Accessory Pigments (e.g. Chlorophyll b, carotenoids, anthocyanin, etc.)
Where does photosynthesis occur?
The Plant Cell’s Chloroplast
Chloroplast Structure
Six Parts | Remember: Structure correlates to function!
- Football shaped
- Double membrane
- Stroma
- Thylakoid membrane
- Grana (stacks)
- Lumen (inside thylakoid)
The Light and “Dark” (Calvin Cycle) or Carbon reactions happen at different sites in the chloroplast
Where naghahappen yung Light Reactions?
Where naghahappen yung Dark Reactions?
Light Reactions - Thylakoid
Dark Reactions - Stroma
Process of Light Reaction (Thylakoid)
Input:
Light (Sun), Water (H2O)
- ____ dependent
- Occurs in the ____ ____ of chloroplasts
- Water is split into ____ ____ (O2) and ____ ____ (H⁺)
- Use light energy (photons) to generate two
chemical energy compounds: ____ &
____
- Light Dependent
- Occurs in the thylakoid membrane of chloroplasts
- Oxygen Gas and Hydrogen Ions (Protons)
- ATP & NADPH
Chemical energy compounds made in the light reactions
____ + ___ + Energy 🡨🡪 ATP
NADP⁺ + ___ + H⁺ 🡨🡪 NADPH
- ADP (Adenosine Diphosphate) + Pi (Inorganic Phosphate) + Energy 🡨🡪 ATP (Adenosine Triphosphate)
- NADP⁺ + 2e- + H⁺ 🡨🡪 NADPH (Nicotinamide Adenine Dinucleotide Phosphate)
Chemical energy compounds are made from light energy, water is split into O2 and protons
Light Reactions
Process of “Dark” or Carbon Reactions (Stroma)
Input:
Light (Sun), Water (H2O)
- Light ____ (can occur in light or dark;
some enzymes require activation by light) - Occurs in the ____ of chloroplasts
- Use the chemical energy produced in Light
Reactions (ATP; NADPH) to reduce ____ to
____ (sugar). - CO2 is converted to sugar by entering the ____ ____
- Light Independent
- Occurs in the Stroma of chloroplasts
- To reduce CO2 to Carbohydrate (sugar)
- the Calvin Cycle
What Cycle is this?
- Named from Melvin Calvin
- __ phases, __ steps
- CO2 goes __ cycles to produce 1 glucose
Calvin Cycle
- 3 phases, 13 steps
- 6 cycles to produce 1 glucose
The Calvin Cycle
- ____ enters the Calvin Cycle
- First product is a 3-carbon molecule: 3-PGA
(____ ____). That’s why it’s also
called C-3 cycle. - Enzyme RuBisCO (____ ____ ____ / ____) is the main enzyme that catalyzes the first reactions of the Calvin Cycle.
- CO2 enters the Calvin Cycle
- 3-PGA (Phosphoglyceric Acid)
- RUBISCO (Ribulose Bisphosphate Carboxylase/Oxygenase)
Is the most abundant protein on
earth!
RuBisCO
Most plants use the Calvin Cycle to Convert CO2 into sugars.
These plants are called ____ _____
C-3 Plants
This reaction uses CO2 and chemical energy (ATP & NADPH) to produce sugars by means of the Calvin Cycle
Carbon Reactions
Photosynthesis Summary
- produced ____ & ____ (energy)
- consumed ____ and produced ___ and H+ as byproduct
- ATP & NADPH
- consumed H2O and produced O2
Calvin Cycle Summary
- consumed CO2 and produced ___ (sugar)
- Regenerated ___ and ____ (recycled siya)
- produced G3P (sugar)
- Regenerated ADP and NADP
Calvin Cycle Summary
- builds ____
- uses ___ & ____ (energy)
- recycles ___ & ____ back to make more (energy)
- builds sugars
- uses ATP & NADPH
- recycles ADP & NADP back to make more ATP & NADPH
Process of making energy of food available in
the cell…
Involves breaking down complicated molecules 🡪 into simple molecules
The energy held by complicated molecules is held
temporarily as ATP (energy currency)
Respiration occurs mainly in Mitochondria and Cytoplasm
Ex. Glucose into Carbon Dioxide (C6H12O6 🡪 CO2)
Respiration
Three Main Stages of Respiration
- ____
- ____ ____
- ____ ____ ____
- Glycolysis
- Krebs Cycle
- Electron Transport System
Splitting of glucose – 2 net ATP generated
3 Stages of cellular respiration
Glycolysis
Energy of glucose molecule is harvested
3 Stages of cellular respiration
Krebs Cycle
also happens in the
mitochondria, more ATP are generated (32).
3 Stages of cellular respiration
Electron Transport System
For each glucose molecule, total ATP = __
Only __% efficient, rest is lost as heat.
1 glucose = 36 total ATP
Only 39% efficient
____ - ability to do work
Newton’s First Law of Thermodynamics
“____ cannot be created or destroyed, it
can only be transformed from one form
to another”
Once a cell has used ____ to do work, it cannot
be used again by any organism.
Energy
Sun 🡪 Earth 🡪Producers 🡪1st deg consumers 🡪 2nd deg consumers
Energy flows into ecosystem from the sun
Energy travels in a straight line by way of food chains.
Energy Flow is LInear
However, much energy is lost as ____ along the
way – as a result of respiration.
Approximately __% energy is lost on each step!
Newton’s Second Law of Thermodynamics:
“In any transfer of energy there is always a
loss of useful energy to the system, usually in
the form of ____”
- heat
- 90% energy is lost
- heat
