Quiz Study Guide - Cell Energy Process
1. Photosynthesis – A process where plant cells use the energy from sunlight to make food (glucose,
C6H12O6) from carbon dioxide (CO2) and water (H2O). Photosynthesis takes place in chloroplasts.
Photosynthesis is the basis for most food chains. We depend on this process for our energy too!
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Take place in plants, some protists, and some bacteria
Plants (and other organisms) use sun’s energy to make sugar (glucose)
Chlorophyll is the green pigment in plants that traps the sunlight energy needed for this process
Photosynthesis can be summarized by the following equation:
6 CO2
+ 6 H2O + light energy
Carbon dioxide + water
+
sunlight
C6H12O6
yields
glucose
+
+
6 O2
oxygen
2. Cellular Respiration - Organisms use cellular respiration to get energy from food. During cellular
respiration, food (glucose) is broken down into CO2 and H2O, and energy is released.
Cellular respiration needs oxygen in order to happen.
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Cellular Respiration happens in most cells
Cells break down sugar to make ATP (energy)
Process occurs in the mitochondria
MUST HAVE OXYGEN!!!
The equation for cellular respiration is:
C6H12O6
Glucose
+ 6 O2
+
Oxygen
6 CO2
yields
+ 6 H2O + Energy (ATP)
Carbon dioxide
+
water
+
energy
3. Fermentation – The process of breaking down food without the use of oxygen.
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Can happen in many cells
Makes ATP by breaking down sugar
Not the most efficient way to break down food
Makes lactic acid (in humans) or alcohol as a result
Only used if enough oxygen is not available (this is the big difference between cellular
respiration and fermentation).
Fermentation continued …
The equation for fermentation looks like this:
C6H12O6
ATP + Lactic Acid or Alcohol
Lactic acid leads to fatique in muscles after strenuous activity.
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* How are cellular respiration and photosynthesis related?
They are a giant cycle inside the cell. The reactants of photosynthesis are the products of cellular
respiration and vice versa.
Know these!!!
O2 - Oxygen
CO2 - Carbon Dioxide
C6H12O6 – Glucose
H2O - Water