1 Flashcards
What is photosynthesis?
Photosynthesis is a process by which plants turn sunlight, water, and carbon dioxide into glucose and oxygen.
The chemical reaction:
6CO2 + 6H2O —> C6H12O6 + 6O2
What are plants?
Plants are living organisms that eat, drink, breathe, and reproduce.
What are autotrophs?
Organisms that can make their own food from inorganic substances like carbon dioxide and water in the presence of chlorophyll and sunlight.
What are heterotrophs?
Organisms that are unable to make their own food and therefore have to rely of other sources specifically plant and animal matter.
How does a solar-powered calculator relate to photosynthesis and the use of sunlight?
Photosynthesis a natural process in plants converts sunlight into glucose, while photovoltaic cells power a solar-powdered calculator converting sunlight into electrical energy for electronic components. While sunlight is used as energy in both processes their functions and modes of operation are different.
Where does almost all the energy in living systems come from?
The sun
What does metabolism involve?
Metabolism involves either using energy to build molecul or breaking down molecules in which energy is stored.
What are photosynthetic organisms?
Producers or autotrophs. They make their own chemicals energy (plants, algae, bacteria)
What does food contain?
Food contains organic compounds that store chemical energy in their bonds (carbohydrates, proteins, lipids).
What does digestion do?
Digestion breaks food down into smaller molecules that could possibly be put back together to make ATP.
What is visible light?
Visible light is a region of the electromagnetic spectrum made of of several colors at different wavelengths.
What do the sugars that are produced during photosynthesis allow the plant to do?
They allow the plan to build more cells and grow.
What are pigments?
Light absorbing substances
What is chlorophyll?
Chlorophyll is a primary pigment involved in photosynthesis. It absorbs blue and red wavelength and it reflects green yellow wavelength.
Where is chlorophyll found?
Chlorophyll is found in chloroplasts (organelles that are only found in plants).
What are thylakoids?
Thylakoids inside the chloroplasts are disc-shaped structures that hold the pigments which absorb the light energy.
What are stacks of thylakoid, singular and multiple?
Singular: granum Multiple: grana
Explain the structure of a chloroplast?
Chloroplast are surrounded by two envelope membranes and they are filled with sac-like chlorophyll containing membranes called thylakoids and the outside is filled with a fluid called the stroma.
What is the fluid portion of the chloroplast?
It is known as the stroma.
What does ATP carry?
ATP carries the energy that cells can use and its chemical bonds.
What is the difference between ATP and ADP?
ATP is adenosine triphosphate.
ATP plays an important role in the transport of macromolecules such as lipids and proteins in and out of the cells. ADP is adenosine diphosphate.
ADP is important for releasing and storing energy within an organism.
Where does photosynthesis occur?
In the plant leaves.
What does chlorophyll trap?
Solar energy to use it in the reaction.
Anthocynanins:
Anthocyanins absorb light in the blue-green wavelengths allowing the red wavelengths to be scattered by the plant tissues to make these organs visible to us as red.
Photosynthesis has 2 sets of reactions:
- Light Dependent
- Light Independent (Calvin Cycle)
Why are ATP and NADPH critical products of light- dependent reactions?
They are needed to make sugars in the next cycle.
What is the purpose of the Calvin Cycle?
Convert CO2 from the atmosphere into carbohydrates(sugars) which the plants needs to power its cellular activities and build new plant structures.
Where does the Calvin Cycle occur?
In the stroma of the chloroplast.
Light dependent:
Light independent:
- energy is captured and transferred to electrons.
- energy in the form of ATP and NADPH is used to create sugars.
Needs of light-dependent reactions:
12 ATP —> 12 ADP
12 NADPH —> 12 NADP+
6 ATP —> 6 ADP
Total: 18 ATP and 12 NADPH
Photosystem structure:
Protein capturing pigments.
Photosystems function:
Absorption and transfer of light energy which implies transfer of electrons.
Photosystems location:
Photosystems are found in the thylakoid membranes.
How does NADPH function like ATP?
They are both energy-carrying molecules.
Steps of light-dependent reactions:
- Light will excite electrons to move from photosystem 2 to electron transport chain then to photosystem 1.
- H2O will be broken down to give O2, H+, and replace the lost electrons in photosystem 2.
- With the transfer of electrons H+ will be pumped from the outside to the inside of the thylakoids.
- 2 electrons and one H+ will be transferred to NADP+ converting it to NADPH.
- H+ will diffuse to the outside of the thylakoids converting ADP+ P: into ATP (energy) by ATP Synthase.
Products of light-dependent reactions:
2 H+ + NADP+ —> 4 Electrons—> 2 NADPH
2 H2O —> 4H+ + O2 + 4 Electrons
Thylakoids:
Fattened sac-like membranes.
Stroma:
Fluid-filled space outside the grana.
Recycled materials in photosynthesis:
NADP+, NADPH, ADP, ATP
Steps of the Calvin Cycle:
— 6CO2 molecules are added to 6 five-carbon molecules to form 12 six-carbon molecules.
- Energy (12 ATP and 12 NADPH) is used by enzymes to split the six-carbon molecules into 12 three-carbon molecules.
- Two of the three-carbon molecules exits the cycle. It will meet up with another three carbon molecule to form a six-carbon molecule of glucose sugar.
- ATP is used to change the 10 remaining three-carbon molecules into five-carbon molecules to be used again.
