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PRE-LABS WEEK 3
Name of students: Nguyen Giang Yen Tho
Student’s ID: BTFTIU18118
1. What are autotrophs and heterotrophs? Give each one example.
- Autotrophs and Heterotrophs are living organisms obtain chemical energy in one of two ways.
Differences between Autotrophs and Heterotrophs:
AUTOTROPHS:
o Food is chemical energy stored in
carbohydrates.
o Food provides both the energy to do
work and the carbon to build
bodies.
o Transform sunlight to make food,
which is called a Photosynthesis
process.
o The beginning of the food chain.
Most of the animals along with the
heterotrophs depend on this to live
their life-cycles and balance the food
chain. Seen as the producers of the
food chain
For instance: Plants are the most
obvious autotrophs, Fungis, Bacteria.
HETEROTROPHS:
o Cannot make their own food, so
they must eat or absorb it
o Seen as consumers of the food
chain.
o Only autotrophs can transform that
ultimate, solar source into the
chemical energy in food that powers
life.
o Diverse, help to balance the biodiversity, maintain the ecologicalbalance.
For instance: animals, humans, etc.
2. What is “photosynthesis”? How many stages are there in the photosynthesis?
Describe.
o Photosynthesis is the process by which plants, some bacteria and some protistants use
the energy from sunlight to produce glucose from carbon dioxide and water. This
glucose can be converted into pyruvate which releases adenosine triphosphate (ATP) by
cellular respiration. Oxygen is also formed.
o It is a process of two stages.
-
The Light dependent reactions, a light-dependent series of reactions which occur in
the grana, and require the direct energy of light to make energy-carrier molecules that
are used in the second process:


light energy is trapped by chlorophyll to make ATP (photophosphorylation)
at the same time water is split into oxygen, hydrogen ions and free electrons:
2H2O
4H+ + O2 + 4e- (photolysis)
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PRE-LABS WEEK 3
Name of students: Nguyen Giang Yen Tho
Student’s ID: BTFTIU18118
 the electrons then react with a carrier molecule nicotinamide adenine dinucleotide
phosphate (NADP), changing it from its oxidised state (NADP+) to its reduced state
(NADPH):
NADP+ + 2e- + 2H+
-
NADPH + H+
The light-independent reactions, a light-independent series of reactions which occur in
the stroma of the chloroplasts, when the products of the light reaction, ATP and NADPH,
are used to make carbohydrates from carbon dioxide (reduction); initially
glyceraldehyde 3-phosphate (a 3-carbon atom molecule) is formed.
3. Where is the chlorophyll distributed in plants and animals?
o Chlorophyll is a complex molecule.
PLANTS:
o Several modifications of chlorophyll occur among plants and other photosynthetic
organisms.
o All photosynthetic organisms have chlorophyll a. Accessory pigments absorb energy that
chlorophyll a does not absorb.
o Chlorophyll is found in the thylakoid sacs of the chloroplast.
ANIMALS:
o There is no Chlorophyll found in animals.
4. What is the function of chlorophyll?
o Chlorophyll is a green photosynthetic pigment found in plants, algae, and cyanobacteria.
PRE-LABS WEEK 3
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Name of students: Nguyen Giang Yen Tho
Student’s ID: BTFTIU18118
o Chlorophyll absorbs mostly in the blue and to a lesser extent red portions of the
electromagnetic spectrum, hence its intense green color.
o Green substance in producers that traps light energy from the sun, which is then used
to combine carbon dioxide and water into sugars in the process of photosynthesis
Chlorophyll is vital for photosynthesis, which helps plants get energy from light.
o Chlorophyll molecules are specifically arranged in and around pigment protein
complexes called photosystems, which are embedded in the thylakoid membranes of
chloroplasts.
5. Define the terms “transpiration” and “respiration”. What is the difference between
them?
RESPIRATION:
o Respiration is the process by which plants convert carbon dioxide to oxygen as a part of
photosynthesis.
o Plants process carbon dioxide to produce energy, so this process is often considered as
part of the carbon cycle and the mitigation of global warming due to atmospheric
carbon dioxide.
o Since plants use carbon dioxide as part of photosynthesis, they remove that carbon
dioxide from the atmosphere.
TRANSPIRATION:
o Transpiration is the process of water movement inside of the plant's system. This means
water drawn from roots and leaves, up through the stem and cells of the plant. This
water movement distributes minerals and is essential to the plant's survival.
6. What are stomata and guardcells? Describe their distribution on the leaf.
o Guard cells are cells surrounding each stoma. They help to regulate the rate of
transpiration by opening and closing the stomata.
- These adjust the size of the opening by opening or closing. To open a guard
cell, protons (hydrogen ions, H+) are pumped into the guard cells. Water enters them,
the cells get hard, and they push open.
PRE-LABS WEEK 3
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Name of students: Nguyen Giang Yen Tho
Student’s ID: BTFTIU18118
o Stomata open and close to allow the intake of carbon dioxide and the release of oxygen.
It's very vital that they do this because this is the very oxygen that we ourselves need to
breathe.
- They are mostly found on the under-surface of plant leaves.[1] In a stoma, there is
the chloroplast, a cell wall, a vacuole and a cell nucleus.