How do photosynthetic cells use light to change carbon dioxide and water into organic molecules and oxygen?
Carbon dioxide and water are used in photosynthesis. Photosynthesis will also use light energy in order to generate organic molecules and dioxide from the CO2 and H2O that we started with.
These organic molecules are then used in cellular respiration which generate ATP and our starting molecules. Now the cycle can take place again.
Photosynthesis
The process that converts light energy into chemical energy stored in sugars and other organic molecules
Photosynthesis takes place in which organisms?
Plants, algae, and some photosynthetic prokaryotes
Directly or indirectly, _____ will nourish the entire living world.
Photosynthesis
What are the two types of organisms with regard to how they gain their energy?
Autotrophs and Heterotrophs
Autroph
An organism that sustains itself without eating anything derived from other organisms. It makes its own food inside its body.
Almost all plants are *_*
Autotrophs and producers (they provide nutrients and oxygen for other organisms)
Photoautotroph
Organisms that use light as a source of energy to synthesize organic substances (ex: plants)
Heterotroph
An organism that obtains organic food molecules by eating other organisms or substances derived from them
Consumers
Living organisms that have to hunt, gather and eat their food. They are heterotrophs.
Decomposers
Organisms that break down dead and decaying organic matter. They are also considered heterotrophs/consumers because they consume organisms for their energy instead of producing their own food.
Chloroplasts
An organelle found in plants and photosynthetic protists that absorb sunlight and use it to synthesize organic compounds from CO2 and H2O
They are the site of photosynthesis.
_____ are the major sites of photosynthesis in most plants.
(Chloroplasts are the site of photosynthesis but this question is asking about which part of the plant does the photosynthesis)
Leaves
Mesophyll
The tissue of the interior of the leaf. The cells of this tissue are specialized for photosynthesis.
Chloroplasts are found mainly in the cells of the ____
Mesophyll
In C3 and CAM plants, mesophyll cells are located where?
Between the upper and lower epidermis
In C4 plants, mesophyll cells are located where?
Between the bundle-sheath and the epidermis
Stoma (plural, stomata)
A microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allow gas exchange between the environment and the interior of the plant
CO2 enters the leaf and O2 exits, by way of microscopic pores called ____
Stomata
A typical mesophyll cell has about how many chloroplasts?
About 30 to 40
A chloroplast has how many membranes?
Two
Stroma
The dense fluid within the chloroplast that is involved in the synthesis of organic molecules from CO2 and H2O
Stroma surrounds the _____
thylakoid membrane
Stroma contain ____
Ribosomes and DNA
Thylakoid
A flattened, membranous sac inside a chloroplast. Thylakoid membranes convert light energy to chemical energy of ATP and NADPH
Thylakoids often exist in interconnected stacks called _____
Grana
Chlorophyll
A green pigment that gives leaves their color. Located in thylakoid membranes of the chloroplasts.
Light absorbed by _____ drives the synthesis of organic molecules in the chloroplasts
Chlorophyll
6CO2 + 12 H2O + Light Energy → C6H12O6 + 6O2 + 6H2O
This is the equation of _____
Photosynthesis
Carbon dioxide + water + light energy become Glucose, Dioxide, and Water
Photosynthesis and _____ undo each other
Cellular respiration
Chloroplasts split water into _____, incorporating the electrons of hydrogen into sugar molecules
Hydrogen and Oxygen
What type of process is photosynthesis?
Redox Process
How is photosynthesis a redox process?
It oxidizes water and reduces carbon dioxide
Photosynthesis consists of two processes. These two stages are ______.
Light reactions (the photo part of photosynthesis) and the Calvin Cycle (the synthesis part of photosynthesis)
Light reactions
The first stage in photosynthesis. These reactions convert solar energy to ATP and NADPH, split water and release oxygen
Light reactions take place where?
On the thylakoid membranes of the chloroplasts or on the membranes of certain prokaryotes
Calvin Cycle
The second stage of photosynthesis. This stage involves fixation of atmospheric CO2 and reduction of the fixed carbon into carbohydrate. Produces sugar.
NADP+
An acceptor. This is the oxidized form of Nicotinamide Adenine Dinucleotide Phosphate, an electron carrier that can accept electrons, becoming NADPH.
Light reactions use solar energy to reduce NADP+ to _____ by adding a pair of electrons along with an H+
NADPH
NADPH
The reduced form of NADP+ (nicotinamide adenine dinucleotide phosphate).
It temporarily stores energized electrons produced during the light reactions. It also reduces electron acceptors.
Function of NADPH
Temporarily stores energized electrons produced during the light reactions and reduces electron acceptors
Photophosphorylation
The process of generating ATP from ADP and phosphate by means of chemiosmosis. This process is done during light reactions.
What is the energy currency of cells?
ATP
Calvin cycle is named after ____
Melvin Calvin
The first step of the Calvin cycle is carbon fixation, which is?
The initial incorporation of carbon from CO2 into an organic compound by an autotrophic organism
Light
A form of energy known as electromagnetic energy, also called electromagnetic radiation
Like other electromagnetic energy, light travels in _____
Rhythmic waves
Wavelength
Distance between crests of waves
Wavelength determines ____
The type of electromagnetic energy
Electromagnetic Spectrum
The entire spectrum of electromagnetic radiation, ranging in wavelength from less than a nanometer to more than a kilometer
Visible Light
The segment of the electromagnetic spectrum that can be detected as various colors by the human eye, ranging in wavelength from about 380nm to about 740nm
Photons
A quantum, or discrete quantity, of light energy that behaves as if it were a particle
Light behaves as though it consists of discrete particles called _____
Photons
The amount of energy is inversely related to the wavelength of the light. The shorter the wavelength, the ____ the energy of each photon of that light and vice versa.
Greater
Plants like which light colors?
Blue (450-500nm) and Red (650-750nm)
Gamma Rays can result in what illness?
Cancer
X-Rays can result in what illness?
Sterility
UV Rays if long term can give you what illness?
Skin Cancer
UV Rays can be seen by which animals?
Birds and insects
Infrared light can be seen by which animals?
Reptiles, bats, and insects
Pigments
Substances that absorb visible light. Different pigments absorb different wavelengths.
Wavelengths that are not absorbed are _____
Reflected or transmitted. For example, chlorophyll looks green because it does not absorb green wavelengths.
Absorption Spectrum
A graph plotting a pigment’s light absorption versus wavelength
Spectrophotometer
An instrument that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment solution
Chlorophyll a
The main photosynthetic pigment. It participates directly in light reactions.
Chlorophyll b
An accessory photosynthetic pigment that transfers energy to chlorophyll a.
Action Spectrum
A graph that profiles the relative effectiveness of different wavelengths of radiation in driving a particular process
The absorption spectrum of chlorophyll a suggests that these two colors work best for photosynthesis: ______
Violet-blue and Red
Other accessory pigments include Carotenoids, which are?
An accessory pigment, either yellow or orange, in the chloroplasts of plants and in some prokaryotes. By absorbing wavelengths of light that chlorophyll cannot, carotenoids broaden the spectrum of colors that can drive photosynthesis.
Accessory pigments, such as chlorophyll b, function to _____. These pigments are also called carotenoids.
Broaden the spectrum used for photosynthesis
When a pigment absorbs light, its state changes from _____ to ____
Ground state to excited state which is unstable
When excited electrons fall back to the ground state, photons are given off, an afterglow called _____
Fluorescence
Photosystem
A light-capturing unit is located in the chloroplast's thylakoid membrane or in some prokaryotes' membranes.
Below is extra info I will put on a separate question:
There are two types of photosystems: Photosystems 1 and 2
A photosystem consists of a reaction-center complex surrounded by numerous light-harvesting complexes
There are two types of photosystems; What are they?
Photosystem I and Photosystem II (they are numbered by the order of their discovery)
A photosystem is composed of _____
A reaction-center complex surrounded by several light-harvesting complexes. These light-harvesting complexes funnel the energy of photons to the reaction center.
Reaction-Center Complex
An organized association of proteins holding a special pair of chlorophyll a molecules and a primary electron acceptor.
Where is the reaction-center complex located?
Center of a photosystem
What triggers the light reactions of photosynthesis?
Reaction-Center Complexes
Light-Harvesting Complex
A complex of proteins associated with pigment molecules that captures light energy and transfers it to reaction center pigments in a photosystem
Includes chlorophyll a, chlorophyll b, and carotenoids
The two photosystems work together to use light energy to generate ______
ATP and NADPH
Photosystem II functions first and is best at absorbing a wavelength of _____
680nm (red)
Photosystem I is best at absorbing a wavelength of _____
700 nm
Photosystem I is used to create _____
NADPH
Photosystem II is used to make _____
ATP
Primary Electron Acceptor
In the thylakoid membrane of a chloroplast or in the membrane of some prokaryotes, a specialized molecule that shares the reaction-center complex with a pair of chlorophyll a molecules and that accepts an electron from them
The first step of the light reactions is?
Solar-powered transfer of an electron from a chlorophyll a molecule to the primary electron acceptor
Photosystem II
One of two light-capturing units. It has two molecules of P680 chlorophyll a at its reaction center
Located in a chloroplast’s thylakoid membrane or in the membrane of some prokaryotes.
Photosystem I (PS I)
One of two light capturing units. It has two molecules of P700 chlorophyll a at its reaction center
Located in a chloroplast’s thylakoid membrane or in the membrane of some prokaryotes
Linear/Noncyclic Electron Flow
The primary route of electron flow during the light reactions that involves both photosystems and produces ATP, NADPH, and O2. The net electron flow is from H2O to NADP+
Cyclic Electron Flow
A route of electron flow during the light reactions of photosynthesis that uses only photosystem I and produces surplus ATP, satisfying the higher demand in the Calvin Cycle
Similarities and Differences Between Chemiosmosis in Chloroplasts and Mitochondria
Chloroplasts and mitochondria generate ATP by _____but have a different source of energy
Mitochondria transfer chemical energy from food to ATP; Chloroplasts transform light energy into the chemical energy of ATP
The spatial organization of chemiosmosis different in chloroplasts and mitochondria
Chemiosmosis
Similarities and Differences Between Chemiosmosis in Chloroplasts and Mitochondria
Chloroplasts and mitochondria generate ____ by chemiosmosis but have a different source of energy
Mitochondria transfer chemical energy from food to ATP; Chloroplasts transform light energy into the chemical energy of ATP
The spatial organization of chemiosmosis different in chloroplasts and mitochondria
ATP
Similarities and Differences Between Chemiosmosis in Chloroplasts and Mitochondria
Both give energy to ATP, but how is it different for mitochondria and chloroplast?
Mitochondria transfer chemical energy from food to ATP and chloroplasts transform light energy into the chemical energy of ATP
The Calvin Cycle used ATP and the reducing power of NADPH to convert CO2 to ____
Sugar
Like the citric acid cycle, the calvin cycle will _____
regenerate its starting material after molecules enter and leave the cycle
___ enters the Calvin Cycle as CO2 and leaves as a sugar named glyceraldehyde-3-phosphate (G3P)
Carbon
Carbon enters the Calvin Cycle as CO2 and leaves as a sugar named _____
glyceraldehyde-3-phosphate (G3P)
glyceraldehyde-3-phosphate (G3P)
A three-carbon carbohydrate that is the direct product of the Calvin Cycle; it is also an intermediate in glycolysis
For the net synthesis of one G3P, the calvin cycle must take place how many times?
Three times, therefore also needed 3 molecules of CO2
The Calvin Cycle has 3 phases. What are they in order?
Carbon Fixation, Reduction, and Regeneration