Unit 5 Lesson 3: Photosynthesis: Energy conversion Flashcards
What is photosynthesis
Photosynthesis is the process of taking light energy, water, and carbon dioxide to make sugars and oxygen.
How is light energy from the sun stored
Light energy from the sun is stored as chemical energy in the bonds of the sugar molecules. This chemical energy can be used in the future.
Where does photosynthesis take place
Photosynthesis takes place inside the chloroplasts of plants and other photosynthetic eukaryotes.
What is the role of Chlorophyll
Chlorophyll and other pigments, molecules that absorb light energy from the sun, are inside the outer membrane of the thylakoids.
What happens during light-depedent reactions
Light-dependent reactions of photosynthesis happen within chloroplasts. During the light-dependent stage, chlorophyll in the thylakoid membranes absorb light energy from the sun and use it to split water molecules into oxygen ions and hydrogen ions.
What does light energy do to water
Light energy from the sun makes low energy electrons from water into very high energy electrons.
Every pair of water molecule makes..
Every pair of water molecule makes two negatively charged oxygen ions, four positively charged hydrogen ions, and four very high-energy electrons.
Every pair of water molecule makes two negatively charged oxygen ions, four positively charged hydrogen ions, and four very high-energy electrons. What does this result in
The oxygen ions bind together, becoming an oxygen molecule, and are released into the atmosphere.
What binds to an electron carrier called NADP+ to become NAPH
One hydrogen ion and two of the high-energy electrons bind to an electron carrier molecule, called NADP+, to become NADPH.
What is NADP+
nicotinamide adenine dinucleotide phosphate; an electron carrier molecule that accepts two high-energy electrons and one hydrogen ion to become NADPH
What is NADPH
nicotinamide adenine dinucleotide phosphate hydrogen; a product of the light-dependent reactions of photosynthesis used to power some of the reactions in the light-independent stage of photosynthesis
What does NADPH do
NADPH stores energy from the electrons by binding them to hydrogen ions, and moves them to many places, including the stroma.
Where is NADPH used
NADPH is used in the light-independent reactions of photosynthesis.
What is ADP
adenosine di-phosphate; a lower energy, intermediate molecule used to convert to ATP by adding a third phosphate group/ADP, adenosine diphosphate, is a lower energy molecule that is changed to ATP by adding a third phosphate group.
What does chlorophyl, light energy, ADP ATP have to do with each other
Chlorophyll also uses light energy to attach a third phosphate group to ADP, making ATP.
What is ATP role in cells
ATP, adenosine triphosphate, is a molecule that carries energy inside cells
ATP is the product of waht
ATP is a product of the light-dependent reactions of photosynthesis.
Where is ATP made
ATP is made across the thylakoid membrane.
As water molecules are split, hydrogen ions are moved inside the thylakoid. So many hydrogen ions cross the membrane that there is a large difference in charge between the inside and the outside of the thylakoid.
Inside of thylakoid VS outside
The inside is positively charged and the outside is negatively charged.
Why cant thylakoid reblance itself
Normally the charges would rebalance themselves, but hydrogen ions cannot pass back through the thylakoid membrane without help.
To rebalance both sides, a large protein called ? allows the hydrogen ions to pass through the membrane.
ATP synthase
What is ATP synthase
a protein that creates ATP from ADP during photosynthesis
What does the roation of ADP allow the cell to do
The rotation allows adenosine di-phosphate (ADP) to bond with a third phosphate group, making adenosine tri-phosphate (ATP). The energy stored in this new bond is what makes ATP a higher-energy output. ATP stores this energy until it is needed by the cell. When a cell needs energy, a phosphate group splits off from ATP releasing energy stored in the bond. This leaves ADP and a free phosphate group ready to be rebonded. ATP is like a charged rechargeable battery and ADP is like a used rechargeable battery.
Changes in the energy levels of compounds also take place during the..
light-independent phase of photosynthesis
What happens when hydrogen ions pass thorugh ATP synthase
As the hydrogen ions pass through ATP synthase, the protein rotates
What is carbon dioxide used for
Carbon dioxide, a lower energy input, is used to make sugars, high energy outputs.
The ATP and NADPH that were made in the light-dependent stage are moved to
the stroma and are used in the light-independent stage, also called the Calvin cycle.
How is ATP and NADPG used int eh body
ATP and NADPH have a lot of chemical energy, but the molecules are not stable enough for long-term storage. An organism would use up the energy in ATP and NADPH quickly, so the plant uses this energy to make sugar molecules, which are more stable and store more energy.
What is co2 used for during the Calvin cyce
. During the Calvin cycle, carbon dioxide is used to make larger carbon molecules.
What are ATP and eclectrons from NADPH used for in the calvin cyccle
ATP and electrons from NADPH that were created in the light-dependent reactions are now used to make new carbon molecules that have a much higher energy level.
What are the Carbon moclesus made int he Calvin cycle used for
Two of these new, high-energy carbon molecules are used to make sugars, amino acids, and other compounds.
What happenes tot he rest of the carbon molecules in the Calvin cycle
The rest of the carbon molecules use ATP to get changed back into larger, low-energy carbon molecules and go through the Calvin cycle again.
What common role does CO2, ATP and NADPH have
In the end, the CO2
, ATP, and NADPH have been used to make a stable sugar, which stores all the energy in its chemical bonds.
Which low-energy input is used to make NADPH?
H2O
Give two examples of a low energy input and the higher-energy output it is used to make during photosynthesis.
- carbon dioxide (low) is used to make sugar (high)
- water (low) is used to make NADPH (high)
- ADP (low) is used to make ATP (high)
Explain how the energy in carbon dioxide changes as it goes through the Calvin cycle and becomes a sugar molecule.
Carbon dioxide is a low energy molecule that is converted to a larger carbon-based molecule during the Calvin cycle. This larger molecule is energized by the electrons in NADPH and in ATP.
Two of these new, high-energy carbon molecules are used to make sugars, amino acids, and other compounds. The rest of the carbon molecules use ATP to get converted back into larger, low-energy carbon molecules.
Why do plants make sugars from sunlight instead of just using ATP directly?
ATP is not very stable for long-term storage and is used quickly after it is made.
The energy of photosynthetic inputs is often __________ the outputs.
lower than
What is the output of lower energy H20
The output of lower-energy H2O is NADPH .
What is the output of lovwer enerfgy CO2
The output of lower-energy CO2 is sugar.
If water and carbon dioxide contain low energy, where did the higher energy in the sugars that photosynthesis produces come from?
The chlorophyll in the thylakoid cells captures the light energy from the sun.
What is electricty
Electricity is the movement of electrons through wires.
What happens to an iten using electricy
When an item is using electricity, electrons are flowing from an outlet (or battery) through the wire and back to the energy source. When the item is turned off, the electrons stop moving.
What are solar panels made out of
Solar panels are made up of many small pieces, called photovoltaic cells, that are linked together.
What is a phtotvoltaic cell mde out of
Each photovoltaic cell is made up of two thin pieces of a material such as silicon that conducts, or carries, electricity.
Why are other element s added tosilicon
Silicon is not a great conductor, so engineers add other elements to increase its conductivity.
Where and why is phosphrous used in the photovoltaic cell
Phosphorus is added to the top, making that side of the photovoltaic cell more negatively charged
Where and why is Boron used in the photovoltaic cell
Boron is added to the bottom making that side of the photovoltaic cell more positively charged.
What does the Siliconine + ptotovoltaic + boron create
This results in an electric field where the silicone layers meet.
What happens when sunlight reaches photovoltaic cells
When sunlight reaches the cell, the light energy knocks electrons free from the atoms. The electrons want to move from the negative layer to the positive layer, but the electric field pushes the electrons out, like an electron transport chain.
What happens during the electron transport chain
system by which high-energy electrons are moved to photosystem I and hydrogen ions are pumped into the inside of the thylakoid during photosynthesis
What do metal plates on photovolatic cells do
Metal plates on the sides of the cells collect the electrons and move them to wires, where the electrons flow like any other type of electricity.
Compare how a plant cell and a photovoltaic cell use the energy from the sun.
A photovoltaic cell is similar to a plant cell in that it uses the energy from sunlight to separate electrons from atoms, only it does this in the silicone junction. Both the plant cell and the photovoltaic cell have a charge gradient; the thylakoid is positive, and the top of the panel is positive. The electrons in the photovoltaic cell want to flow from the negative layer to the positive layer. Instead of ATP synthase, an electric field pushes the electrons out of the silicone junction. Metal plates on the sides of the cells collect the electrons and transfer them to wires, where the electrons become usable energy in the form of electricity.
