Light-dependent reactions use energy from sunlight to produce oxygen and convert ADP and NADP+ into the energy carriers ATP and NADPH.
Light-dependent reactions involve the steps of photosynthesis that directly involve
The light-dependent reactions take place in the ___________________of the chloroplast
Thylakoids contain clusters and proteins called________
Photosystems _____________ sunlight
Photosystems absorb sunlight and generate __________________ that are then passed to a series of electron carriers embedded in the thylakoid membrane.
Photosystems absorb sunlight and generate high-energy electrons that are then passed to a series of electron carriers embedded in the_________________.
Light energy is absorbed by electrons in the pigments within the ________________.
The high-energy electrons are passed to the__________________
Electron transport chain
A series of electron carriers that shuttle high-energy electrons during _______________
Energy from the electrons is used by _______________ in the electron transport chain.
Energy from the electrons is used by proteins in the electron transport chain to pump H+ ions from the ______________ into the thylakoid space
Energy from the electrons is used by proteins in the electron transport chain to pump H+ ions from the stroma into the ________________.
At the end of the electron transport chain, the electrons pass to__________________
Pigments in photosystem I use energy from _____________ to reenergize the electrons.
At the end of a short second electron transport chain, NADP+ molecules in the stroma pick up the high-energy electrons and H+ ions at the outer surface of the thylakoid membrane to become _________________
H+ ions accumulate within the___________________ from the splitting of water and from being pumped in from the stroma
This gradient, the difference in both charge and H+ ion concentration across the membrane, provides the energy to make ___________________
The thylakoid membrane contains a protein called __________________ that spans the membrane and allows H+ ions to pass through it.
As it rotates, ATP synthase binds ADP and a phosphate group together to produce __________ .
A process, called _________________, enables light-dependent electron transport to produce not only NADPH but ATP as well.
The light-dependent reactions produce ________________
The light-dependent reactions produce oxygen and convert ADP and NADP+into energy carriers ________________________
ATP and NADPH
ATP and NADPH provide energy needed to build__________
ATP and NADPH provide energy needed to build high-energy sugars from low energy ________________
What happens during the light-independent reactions?
ATP and NADPH from the light dependent reactions are used to produce high-energy sugars
During the light-independent reactions, commonly referred to as the _______________, plants use the energy that ATP and NADPH contains to build stable high-energy carbohydrate compounds.
Carbon dioxide molecules enter the Calvin cycle from
An enzyme in the ___________ of the chloroplast combines carbon dioxide molecules with 5-carbon compounds that are already present in the organelle, producing 3-carbon compounds that continue into the cycle
An enzyme in the stroma of the chloroplast combines carbon dioxide molecules with 5-carbon compounds that are already present in the organelle, producing ______________compounds that continue into the cycle
For every 6 carbon dioxide molecules that enter the cycle, a total of _________________ 3-carbon compounds are produced
At midcycle, two of the twelve 3-carbon molecules are removed from the cycle. These molecules become the building blocks that the plant cell uses to produce ______________ _____________ _______________ and other compounds.
Sugars, lipids, amino acids
The Calvin cycle uses 6 molecules of carbon dioxide to produce a single __________________ molecule
The energy for the reactions is supplied by compounds produced in the ______________________
What factors affect the rate photosynthesis?
Temperature, light and water
The rate of photosynthesis are driven by enzymes that function best between ________________
0°C and 35°C.
High light intensity ____________ the rate of photosynthesis
Plants that live in dry conditions often have ______________ on their leaves to reduce water loss
Some plants have __________________adaptations that make photosynthesis more efficient under dry conditions
C4 plants have a specialized_____________ ______________ that allows them to capture even very low levels of carbon dioxide and pass it to the Calvin cycle.
The name "C4 plant" comes from the fact that the first compound formed in this pathway contains _____________
4 carbon atoms
Members of the Crassulacae family, such as cacti and succulents, incorporate carbon dioxide into organic acids during photosynthesis in a process called __________________
Crassulacean Acid Metabolism (CAM).
During the daytime, when leaves are tightly sealed to prevent water loss, these compounds release _______________ enabling carbohydrate production
What role do pigments play in the process of photosynthesis?
Pigments capture energy from sunlight
Energy from the sun travels to earth in the form of ___________
Sunlight is a _______________of different wavelenghts, many of which are visible to our eyes
Plants gather the sun's energy with light absorbing molecules called_____________________
The principle pigment in plants is called ________________
The two types of chlorophyll found in plants are ____________ _________________
Chlorophyll a and chlorophyll b
Leaves reflect __________________, which is why plants look green
Plants contain red and orange pigments such as ________________ that absorb light in other regions of the spectrum
Most of the time the green color of the chlorophyll __________________ the other pigments but as the temperature drop and chlorophyll molecules break down the red and orange pigments become visible.
Photosynthesis takes place inside organelles called
Chloroplasts contain saclike photosynthetic membranes called________________ which are interconnected and arranged in stacks known as grana.
Chloroplasts contain saclike photosynthetic membranes called thylakoids, which are interconnected and arranged in stacks known as ______________
The fluid portion outside of the thylakoids is known as _____________
When chlorophyll absorbs light, a large fraction of the light energy is transferred to _________________
What are electron carrier molecules?
An electron carrier is a compound that can accept a pair of high-energy electrons and transfer them, along with most of their energy, to another molecule.
The high-energy electrons produced by chlorophyll are_________________
Plants use electron carriers to ______________ high-energy electrons from chlorophyll to other molecules
Nicotinamide adenine dinucleotide phosphate
NADP+ accepts and holds two high-energy electrons, along with a hydrogen ion (H+) hence it is converted into ______________
Photosynthesis uses ______________ to convert water and carbon dioxide (reactants) into high-energy sugars and oxygen (products
Photosynthesis uses the energy of sunlight to convert __________and ____________ (reactants) into high-energy sugars and oxygen (products
Water and carbon dioxide
Photosynthesis uses the energy of sunlight to convert water and carbon dioxide (reactants) into ____________ and ____________ (products
High-energy sugars and oxygen
6 CO2 + 6 H2O - C6H12O6 + 6 O2
Carbon dioxide + water - Sugar + Oxygen
Plants use the sugars generated by photosynthesis to produce complex carbohydrates such as starches, and to provide energy for the synthesis of other compounds, including ___________ and __________
Proteins and lipids.
The first set of reactions is known as the ________________
Light-dependent reactions use energy from sunlight to produce_____________ and ___________
ATP and NADPH
Light-dependent reactions take place in the
Light is not required to power the____________
The light-independent reactions take place outside the thylakoids in the ___________
What is energy
The ability to do work
Cells can release the energy stored in _____________ by breaking the bonds between the second and third phosphate groups
One way cells use the energy provided by ATP is to carry out _______________
ATP powers movement, providing the energy for motor proteins that contract muscle and power the movement of __________
Cilia and flagella
Energy from ATP powers the synthesis of proteins and responses to _______________ at the cell surface
Cells can regenerate ATP from ___________ as needed by using the energy in foods like glucose.
Cells can regenerate ATP from ADP as needed by using the energy in foods like ______________
Process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches
Organisms that obtain food by consuming other living things are known as _________
Heterotrophs that get their food by eating plants _____________
Heterotrophs that get their food by eating other organsisms that consume plants _________
Heterotrophs, such as mushrooms, obtain food by decomposing other organisms