PHOTOSYNTHESIS slide for grade 11 , light phase and dark phase

Photosynthesis life science grade 11

1. PHOTOSYNTHESIS
GRADE 11
By SPHIWE MSHAYISA
222136409

2. WHAT IS PHOTOSYNTHESIS
•Photosynthesis is the process by which plants
create glucose and oxygen using radiant energy
from the sun, water, and carbon dioxide from
the atmosphere. (EddieBoyLaodenio, 2024).
•Let’s look at Figure 1.1
This Photo by Unknown Author is licensed under CC BY-NC-ND
Figure 1.1

3. Let look at the reaction of photosynthesis
Carbon dioxide + Water + Radient energy →
Glucose + Oxygen
•6 CO
2+ 6 H
2O + Light -> C
6H
12O
6+ 6 O
2+ 6
H
2O
• Let’s look at Figure 1.2
This Photo by Unknown Author is licensed under CC BY-SA-NC
Figure 1.2

4. Where does photosynthesis occurs
•Photosynthesis take place in leaves of plant , it
take place in the chloroplast of the leaf
•Figure 1.2
This Photo by Unknown Author is licensed under CC BY
Figure 1.2

5. How does it occur
•Photosynthesis takes place in two
phases, the light-dependent phase
And the light-independent phase, also
known as the dark phase or Calvin
cycle
Let’s dive deep into the two phases of
photosynthesis

6. The light
phase
(light
dependent
phase)
Takes place during the day ,it take place in the grana of the
chloroplast
Green pigment called chloroplyll in the grana traps radient
energy from the sun.
The radient energy is use to split water molecule in the grana
into oxygen and energized hydrogen ion. This is called photolysis
The oxygen is then released onto the atmosphere as a byproduct
(melodiakirim, 2025)
The energy rich hydrogen ion moves into the next phase which is the
light independent phase

7. The light-independent phase
(Calvin cycle)
It take places in the stroma of the chloroplast
•Carbon dioxide is absorbed from the atmosphere
• Carbon dioxide and energy rich Hydrogen (H+) atoms, from the light
dependent phase, are combined by using ATP, from the light dependent
phase to from carbohydrates (glucose)
• Excess glucose is stored as starch in starch granules(Pampanga,2025)
)

8. Phases of photosynthesis explained
This Photo by Unknown Author is licensed under CC BY
Figure 1.4

9. Factors that affect the rate of photosynthesis
•- Light intensity
•Temperature
•Carbon dioxide concentration
•(part, 2019)
• Let’s look at how each factor affects the rate of photosynthesis

10. Light intensity
•Light intensity An increase in light intensity
results in an increase in the rate of
photosynthesis, but only to a maximum level.
• If the light intensity becomes too high, the
stomata close and carbon dioxide then become a
limiting factor. (part, 2019)

11. Temparature
•Plants photosynthesise optimally at 25ᶛC.
Temperatures that are too high or too low
inhibit the rate of photosynthesis.
•At low temperatures, enzymes become inactive,
and at high temperatures, enzymes denature. At
high temperatures, the stomata close to limit
water loss, and then carbon dioxide becomes a
limiting factor once again (cavalierem, 2025)

12. Carbon dioxide
concentration
•A decrease in CO2 concentration
leads to a decrease in the rate of
photosynthesis.
•An increase in CO2 concentration
leads to an increase in the rate of
photosynthesis
•(cavalierem, 2025)

13. •cavalierem (2025).Chapter 6 - Photosynthesis. [online] SlideShare. Available at:
https://www.slideshare.net/slideshow/photosynthesis-15931877/15931877 [Accessed 13 Aug. 2025].
•EddieBoyLaodenio (2024).Lesson 7.pptx The Process of Photosynthesis. [online] SlideShare. Available at:
https://www.slideshare.net/slideshow/lesson-7-pptx-the-process-of-
photosynthesis/282320507?from_search=1&from_action=download_slide&slideshow_id=282320507&index=6#4
[Accessed 13 Aug. 2025].
•melodiakirim (2025).Reactions in photosynthesis for Grade 11 STEM. [online] SlideShare. Available at:
https://www.slideshare.net/slideshow/reactions-in-photosynthesis-for-grade-11-stem/274108123 [Accessed 13
Aug. 2025].
•MHS, Macabebe Pampanga (2025).Photosynthesis. [online] SlideShare. Available at:
https://www.slideshare.net/slideshow/photosynthesis-64957097/64957097 [Accessed 13 Aug. 2025].
•Part (2019).Part 5 Factors affecting photosynthesis.pdf. [online] Google Docs. Available at:
https://drive.google.com/file/d/1apkYdI2DN4tKdOslm0bRTVBC6pmyUoav/view [Accessed 13 Aug. 2025
references

14. Words from one scientist to another
•“Photosynthesis is nature’s recipe for
life – sunlight, water, and carbon
dioxide mixed together to make food
and oxygen for the planet”.

15. Images references
•Figure 1.1 [knowable magazine science(Knowable Magazine Science
Graphics Library | Flickr]
•Figure 1.2 [biologycorner.com(Photosynthesis Coloring (Chemiosmosis)]
•Figure 1.3 [open Oregon (The structure of the chloroplast – Principles of
Biology)]
•Figure 1.4 [Nursing hero (Photosynthesis | Microbiology | Study Guides)]

16. About me visit
•https://about.me/mshayisa