- All organisms need a constant supply of energy to survive
- For most life on earth, the ultimate source of energy is the sun
- Converting that energy source into something usable is accomplished by
photosynthesis
: the overall process by which sunlight (solar/light energy), water,
and carbon dioxide are chemically converted into chemical energy stored in
glucose (a sugar/carbohydrate)
It can be represented by the following chemical equation:
Solar
energy
= ingredients
- CO2 (carbon dioxide) and H2O (water)
= results
- C6H12O6 (glucose) and O2 (oxygen)
- Photosynthesis takes place in the chloroplast which has 2 main parts:
: pancake-like stacks of thylakoid
membrane
: fluid-like substance that fills the space
between the grana
Stroma
Grana
Thylakoid
membrane
- Requires solar energy
Capture energy from the sun and store energy in “energy-carrying
molecules” (ATP and NADPH)
Occurs in the grana (specifically the thylakoid membrane) where the
chlorophyll is stored (chlorophyll is the pigment that captures sunlight)
- Energy from the sun is passed down the Electron Transport Chain and is stored
in the bonds of ATP and NADPH
- Water molecules are split into hydrogen and oxygen
- Oxygen is released as a waste product
- ATP, NADPH, and Hydrogen (H+) leave the grana and go into the stroma for
the next stage!
- Does not require any solar energy
Use the energy from the “energy-carrying molecules” from the lightdependent reaction to make sugar (glucose)
Occurs in the stroma
Calvin Cycle
- Chemical reactions powered by ATP and NADPH combine hydrogen (from
water) with carbon dioxide to form sugar molecules (glucose = C6H12O6)
- Uses CO2 (and H from water) and makes glucose!!
= process of an organism making its own food using chemicals
(“chemo”) instead of sunlight (“photo”) like in photosynthesis
- This is the process that producers who can’t do photosynthesis do to get energy
To convert the chemical energy in food (glucose) to
chemical energy stored in ATP
- We use carbohydrates 1st for energy, but any food can be processed/broken
down as a source of energy
Chemical equation:
= ingredients
- C6H12O6 (glucose) and O2 (oxygen)
= results
- CO2 (carbon dioxide) and H2O (water)
- Cellular respiration takes place in the mitochondria which has 2 main parts:
= folded membranes
= fluid-like substance that fills the space
= the first stage in cellular respiration; the breakdown of glucose
split the 6-carbon molecule of glucose in half to form 2 3-carbon
molecules called pyruvate
this occurs in the cytoplasm, and requires no oxygen, meaning it is
anaerobic
a net of 2 ATP and 2 NADH
present
aerobic respiration
NOT present
fermentation
O 2 present
Glycolysis
O2 absent
Aerobic Respiration
Anaerobic Respiration
Krebs Cycle
Mitochondrial Matrix
2 pyruvate molecules from glycolysis are chemically converted to make 2
ATP (and some NADH and FADH2)
- Releases CO2 as a waste product
Inner membrane of the mitochondria
- A series of reactions using the e- and hydrogens formed in the Krebs Cycle
- Makes 34 ATP and H2O (when hydrogen bonds to oxygen)
- **Most ATP comes from this step!!**
anaerobic respiration
fermentation
There are two main types of fermentation:
- Occurs in some bacteria and animal cells (like your muscles)
- Pyruvate from glycolysis is converted into lactic acid and 2 ATP
- Occurs in yeast when oxygen is not available
- Pyruvate from glycolysis is broken down into alcohol, CO2, and 2 ATP
= 36-38 ATP
- 2 ATP from Glycolysis
- 2 ATP from Krebs Cycle
- 34 ATP from Electron Transport
Chain
Light
energy
= 2-4 ATP
- 2 ATP from Glycolysis
- 2 ATP from fermentation
Photosynthesis
Cellular Respiration
CO2
C6H12O6
CO2
H2O
O2
H2O
ATP
energy
Activity: Journey of a Photon
Overview: In this activity you will pretend you are a photon from the sun. You have just taken a journey from the sun all
the way to now being stored in a molecule of ATP in a human. This has been a crazy ride, and you’ve been through so
much (including 2 key biochemical reactions we’ve been learning about!) and now you want to recount your adventures
to all of your friends on social media.
Task: Select one of the social media options below to share your trip to all of your other energy particle friends.
If you choose Instagram to commemorate your journey, you will be writing #tbt posts, reminiscing on where
you have been. Instagram is all about the pictures and hashtags, and you can use varying lengths of captions.
Just be sure to include a minimum of 5 Instagram posts to reflect on your trip. Every post must include: a
picture, caption, and at least 1 hashtag other than #tbt.
If you choose Twitter to chronicle your journey, you will be “live tweeting” your journey from the Sun to an
ATP molecule in a human. You won’t have to include any pictures, but you do need to include appropriate
hashtags and make sure each tweet is 140 characters or less. You must write a minimum of 20 tweets to
capture your trip.
If you choose Snapchat to chronicle your journey, it is all about the pictures on your Snapchat story. You will
need to create a minimum of 10 Snapchats that would show your followers your journey from the Sun.
Snapchats are all about the pictures, filters, and a very brief caption, so make sure to have excellent pictures if
you choose this option.
If you really aren’t into pictures at all, but would rather write a lengthy post about your emotional trials from
the Sun to where you are now, Facebook is the social media option for you. You have the option of including
one picture in your post about your journey, but the emphasis on this choice is the writing, not the pictures.
You will need to write between 350-500 words about your trip.
Rubric:
Excellent
(10 points)
Student uses their selected
social media method
accurately and effectively
to communicate their
molecule’s journey.
Satisfactory
(9-7 points)
Student mostly uses their
selected social media
method accurately and
effectively to communicate
their molecule’s journey.
Needs Improvement
(6-3 points)
Student somewhat uses
their selected social media
method accurately and
effectively to communicate
their molecule’s journey.
Unacceptable
(2-0 points)
Student does not use their
selected social media
method accurately or
effectively to communicate
their molecule’s journey.
Content
(x2)
The pathway the photon
takes is clearly
understood and
communicated.
The pathway the photon
takes is mostly understood
and communicated.
The pathway the photon
takes is somewhat
understood and
communicated.
The pathway the photon
takes is not understood or
communicated in a way
that shows understanding.
Connections
There is a clear
understanding of the
connection between the
two biochemical
reactions.
There is a mostly clear
understanding of the
connection between the
two biochemical reactions.
There is somewhat of an
understanding of the
connection between the
two biochemical reactions.
There isn’t an
understanding of the
connection between the
two biochemical reactions.
Overall
Overall work is colorful,
visually appealing,
organized, and accurate.
Work stands out from the
rest and shows evidence
of extra effort.
Overall work is mostly
colorful, visually
appealing, organized, and
accurate. and shows
evidence of good effort.
Overall work is somewhat
colorful, visually
appealing, organized, and
accurate. More effort
needed.
Overall work is not
colorful, visually
appealing, organized, and
accurate. Lack of effort is
evident.
Method
Overall Score:
Energy Flow Unit
© It’s Not Rocket Science® 2020
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