Biology Ch.7
Chloroplast consist of...
an envelope of two membranes, which enclose an inner compartment files with a thick fluid called stoma that contains a system of interconnected membranous sacs called B
How did organelles com about?
endosymbiotic theory
Photoautotrophs: __________ us ___________ us ___________ us provide __________,___________, ___________, and _______________ make _____________
feed, clothe, house, energy for warmth, light, transport, manufacturing, oxygen
Photosynthesis _________ the ________________.
fuels, biosphere
What is an example of photosynthesis and cellular respiration?
redox process
Photosynthesis- removes- stores-
removes CO2 from the atmosphere and stores it in plant matter
Where do plants store extra food?
roots, tubers, seeds, and fruits
The ___________ the wavelength, the ______________- the energy.
shorter, greater
How long have scientists known plants oxygen?
since the 1800s
After ___________ and _______ are used __________ and ______________ will be left and will go back over to photosynthesis/light reaction.
NADPH and ATP, ADP and NADP+
What is the chemiosmotic production of ATP called?
Photophosphoyrlation
How does a photosystem work?
The light energy is passed from molecule to molecule within the photosystem. Finally it reaches the reaction center, where a primary electron acceptor accepts these electrons and consequently becomes reduced (gain electrons).
Generally, when isolated pigment molecules absorb light, their excited electrons...
drop back down to the ground state and release their excess energy as heat
Sunlight contains energy called _______________ or _________________.
electromagnetic energy or radiation
Visible light is only a small part of the ____________________.
electromagnetic spectrum
What is light energy tranferred to in photosynthesis?
into the chemical energy of ATP and NADPH
How may global climate change affect plants? (3)
- Increasing CO2 levels can increase plant productivity. - Deforestation- not allowing all the trees to take in the CO2 - Research has documented such an increase, although results often indicate that the growth rates of weeds, such as poison ivy, increase more than those of crop plants and trees.
Within the thylakoid membrane, chlorophyll and other pigment molecules,
- absorb photons - transfer the energy to other pigment molecules
Plant pigments-
- are built into the thylakoid membrane - absorb some wavelengths of light - reflect r transmit other wavelengths
What are the steps of the Calvin cycle?
- carbon fixation, - reduction, - release of one molecule of G3P, and - regeneration of the starting molecule, ribulose bisphosphate (RuBP).
What do photons do for the chloroplast?
- increase the potential energy of the pigments's electrons - sends the electrons into an unstable state
Autotrophs-
- sustains themselves - do not usually consume organic molecules derived from other organism - make their own food through the process of photosynthesis, in which they convert CO2 and H20 to sugars an other molecules.
Chlorophyll molecules
-are built into the thylakoid membrane and -capture light energy.
Thylakoids-
-are often concentrated in stacks called grana and -have an internal compartment called the thylakoid space, which has functions analogous to the intermembrane space of a mitochondrion in the generation of ATP.
What happens in the light reactions?
-water is split, providing a source of electrons and giving off oxygen as a by-product -ATP is generated from ADP and a phosphate group -light energy is absorbed by the chlorophyll molecules to drive the transfer of electrons and H+ from water to the electron acceptor NADP+ reducing it to NADPH -NADPH, produced by the light reactions, provides the "reducing power" to the Calvin cycle. -Splitting water makes 2H+, 1 oxygen, and 2 electrons
What is an ozone molecule made of?
3 oxygen atoms An ozone molecule is a molecule that is composed of three oxygen molecules instead of the normal two. These ozone molecules are a product of the contact between oxygen and the sun's ultraviolet radiation. The ozone layer is below the stratosphere and above the troposphere and is about 6 miles away from the surface of the Earth. The ozone layers serves as a layer of gas that protects the Earth by absorbing harmful UV rays that are emitted by the sun. Ozone depletion is the thinning of the ozone layer due to the harmful gases/compounds (CFC's) that are produced by factories. CFC's are molecules that destroy ozone molecules therefore destroying some of the ozone layer.
What percentage of carbohydrate is made by photosynthesis then consumes as fuel for cellular respiration in the mitochondria of plant cells?
50%
Experiment 1:
6 CO2 + 12 H2O → C6H12O6 + 6 H2O + 6 O2
How are the two stages of photosynthesis linked?
ATP and NADPH
How are things organized in the thylakoid membrane?
In the thylakoid membrane, chlorophyll molecules are organized along with other pigments and proteins into photosystems.
What is the other mode of carbon fixation?
An alternate mode of carbon fixation has evolved that minimizes photorespiration and optimizes the Calvin cycle. C4 plants are so named because they first fix CO2 into a four-carbon compound. When the weather is hot and dry, C4 plants keep their stomata mostly closed, thus conserving water. (more efficient during the calvin cycle)
What is the third adaption in hot and dry environments?
Another adaptation to hot and dry environments has evolved in the CAM plants, such as pineapples, cacti, aloe, and jade. CAM plants conserve water by opening their stomata and admitting CO2 only at night. CO2 is fixed into a four-carbon compound, which banks CO2 at night and releases it to the Calvin cycle during the day. WHEN STOMATA IS OPEN AT NIGHT THEY TAKE IN AS MUCH AS THEY CAN
Photorespiration:
As O2 builds up in a leaf, rubisco adds O2 instead of CO2 to RuBP, and a two-carbon product of this reaction is then broken down in the cell. This process is called photorespiration because it occurs in the light, consumes O2, and releases CO2. But unlike cellular respiration, it uses ATP instead of producing it.
What do C3 plats do in hot and dry weather?
C3 plants close their stomata to reduce water loss, but this prevents CO2 from entering the leaf and O2 from leaving.
What are CFCs?
CFC stands for Chlorofluorocarbon. This is a type of hydrocarbon that is used in most types of refrigerants for building applications such as centrifugal chillers, refrigerators, and humidifiers. Most applications were installed prior to ozone concerns and they are currently being phased out by the Montreal Protocol.
CO2 becomes reduced to _________ as electrons (_______________ electrons), along with hydrogen ions from water, are ______________ to it.
CO2 becomes reduced to sugar as electrons (gaining electrons), along with hydrogen ions (H+) from water, are added to it.
Cellular respiration uses ____________ reactions to ______________ the chemical energy stored in a ________________ molecule.
Cellular respiration uses redox reactions to harvest the chemical energy stored in a glucose molecule.
What does chlorophyll A and B absorb and reflect?
Chlorophyll A- mainly blue-violet and red light and reflect mainly green Chlorophyll B- mainly absorbs blue and orange and mainly reflects olive- green
Chloroplasts are ___________________ in the cells of the ________________, the green tissue in the ______________ of the leaf.
Chloroplasts are concentrated in the cells of the mesophyll, the green tissue in the interior of the leaf.
What happens during the Calvin cycle?
During the Calvin cycle, plants use the energy that ATP and NADPH contain to build high-energy compounds that can be stored for a long time. The Calvin cycle uses six molecules of carbon dioxide to produce a single 6-carbon sugar molecule.
What did scientists discover about oxygen being made?
For many years, it was assumed that oxygen was extracted from CO2 taken into the plant. However, later research using a heavy isotope of oxygen, 18O, confirmed that oxygen produced by photosynthesis comes from H2O. Oxygen had more neutrons so when it gave off they could see that it came from water Yield glucose water and oxygen
Greenhouse Effect: ___________________ passes through the atmosphere and ___________ Earth's surface. ______________________ from the _______________ planet is absorbed by ________________________(absorb that radiation), such as CO2, water vapor, and methane, which then ____________ some of the ___________ back to Earth. Without this ____________________, the average air temperature would be a frigid -18∞C (-0.4∞F), and most life as we know it could not exist. It is needed to _______________-
Greenhouse Effect: Solar radiation passes through the atmosphere and warms the Earth's surface. Heat radiating from the warmed planet is absorbed by greenhouse gases (absorb that radiation), such as CO2, water vapor, and methane, which then reflect some of the heat back to Earth. Without this natural heating effect, the average air temperature would be a frigid -18∞C (-0.4∞F), and most life as we know it could not exist. It is needed to survive
Making Energy:
Hydrogen come from splitting water in the thylakoid space and the hydrogen will flow through ATP synthase after the facilitated diffuion from the stoma to thylakoid space ADP+P=ATP Calvin cycle makes the sugar
In photosynthesis, -light energy is captured by ________________ molecules to _______________ the energy of _________________-, -__________ energy is converted to ______________ energy, and -______________ energy is stored in the ________________________ of _______________. -Electrons come from __________ and go through the _________________________________. -_____________________ will ______________ the electrons
In photosynthesis, -light energy is captured by chlorophyll molecules to boost the energy of electrons, -light energy is converted to chemical energy, and -chemical energy is stored in the chemical bonds of sugars. -Electrons come from water and go through the electron transport chain -Chlorophyll will energize the electrons
How did scientists discover the effects of increasing CO2 on plants?
Many experiments are done in small growth chambers in which variables can be carefully controlled. Other scientists are turning to long-term field studies that include large-scale manipulations of CO2 levels.
Explain carbon fixation?
Most plants use CO2 directly from the air, and carbon fixation occurs when the enzyme rubisco adds CO2 to RuBP. Such plants are called C3plants because the first product of carbon fixation is a three-carbon compound, 3-PGA.
Photosynthesis is a ___________ process, as is cellular respiration
Photosynthesis is a redox process, as is cellular respiration
Explain the intermediates of Calvin cycle.
Rubp (using rubisco+CO2)<carbon fixation WILL REACT WITH CO2 when it splits it will create something else called 3PG (2) the to G3P which will react (using NADPH AND ATP) with another G30 to make glucose and the remaining G3P will be used to regenerate (need ATP) Rubp
How does the electron transport chain work in photosynthesis?
STROMA TO THYLAKOID SPACE
Photosynthesis:
Sunlight hits chlorophyll absorbs energy and give to electrons which travel down electron transport chain activating hydrogen pumps which pump hydrogen from stroma to the thylakoid space energy the electrons have will activate the pumps electrons will move to photosystem 1 and sunlight will hit photosystem one in which the chlorophyll will absorb it and energy the electrons will then leave photosystem and not use energy in the electron transport chain because there are no hydrogen pumps to activate and they will go to NADP+ (+hydrgons) the electrons will reduce it to NADPH
How does the cycle make G3P?
The Calvin cycle uses these three ingredients to produce an energy-rich, three-carbon sugar called glyceraldehyde 3-phosphate (G3P). A plant cell uses G3P to make glucose, the disaccharide sucrose, and other organic molecules as needed.
What does the electron transport chain do in photosynthesis?
The electron transport chain helps to produce the concentration gradient of H+ across the thylakoid membrane, which drives H+ through ATP synthase, producing ATP.
Cellular respiration with glucose and involving the redox reaction
This is accomplished by oxidizing the sugar and reducing O2 to H2O. The electrons lose potential as they travel down the electron transport chain to O2. In contrast, the food-producing redox reactions of photosynthesis require energy. Cellular Respiration Glucose make more energy high to low, photosynthesis will require energy because you go from low to high (endergonic reaction- requires energy)
Thylakoid membranes also house much of the ____________________ that converts ___________________________ to _________________________.
Thylakoid membranes also house much of the machinery that converts light energy to chemical energy.
How does photosynthesis make ATP and NADPH?
To accomplish this, electrons are removed from water, passed from photosystem II to photosystem I, and accepted by NADP+, reducing it to NADPH. Between the two photosystems, the electrons move down an electron transport chain and provide energy for the synthesis of ATP. Photosystem uses photons to re energize
What does a photosystem consist of?
a number of light-harvesting complexes surrounding a reaction-center complex. A light-harvesting complex contains various pigment molecules bound to proteins.
endosymbiotic theory-
a theory that states that certain kinds of prokaryotes began living inside of larger cells and evolved into the organelles of modern-day eukaryotes
What do antenna pigments do?
absorb light energy transfer energy to reaction center
What do pigments do?
absorb light os different wavelengths
Heterotrophs-
are consumers that feed on plants or animals or decompose organic material
Chemoautotrophs-
are prokaryotes that use inorganic chemicals as their energy source. (rearrange sulfur to chemical energy)
What are the necessary ingredients for the Calvin cycle?
atmospheric CO2 (through the stomata) and ATP and NADPH generated by the light reactions.
Plants are...
autotrophs
Why is the Calvin cycle called these names?
because none of the steps require light energy directly
Carotenoids-
broaden the spectrum of colors that can drive photosynthesis and provide photo-protection, absorbing and dissipating excessive light energy that would otherwise damage chlorophyll or interact with oxygen to form reactive oxidative molecules
The ______________ of sugar in the cellular respiration of almost all organisms releases ________ back to the environment.
burning, CO2
Light dependent-
chloroplasts
What is within the thylakoid?
chloroplasts
Where does photosynthesis occur in plants?
chloroplasts
The Calvin cycle is a __________ series.
cyclic
What is the Calvin cycle often called?
dark reactions or light-independent reactions
What do the veins in leaves do?
deliver water absorbed by roots
What do CFCs do?
destroy the ozone layer
Increasing concentrations of greenhouse gases have been linked to _________________, of which one major aspect is global warming.
global climate change
Chlorophyll transmits...
green wavelengths
Chlorophyll- is an important ____________- absorbing ____________ in chloroplasts is responsible for the ____________ color of plants, and plays a _______________ role in converting ____________ energy to ____________ energy.
is an important light-absorbing pigment in chloroplasts is responsible for the green color of plants, and plays a central role in converting solar energy to chemical energy.
What two stages does photosynthesis occur in?
light reactions and calvin cycle
What are some of the predicted consequences of global climate change?
melting of polar ice, rising sea levels, extreme weather patterns, Droughts (rain clouds won't form), increased extinction rates, and the spread of tropical diseases (germs thrive in warm air).
During the Calvin cycle CO2 is incorporated into ______________ _________________ in a process called _______________ ________________.
organic compounds, carbon fixation
Water molecules are _________________ when they _________ electrons along with hydrogen ions.
oxidized, lose
Plants don't need ____________ so what do they do with it?
oxygen (by-product), they give it off
A _____________ is a fixed quantity of light energy.
photon
Light behaves as discrete packets of energy called _______________.
photons
Pigments in chloroplasts absorb
photons
Like all plants, poison ivy produces energy for its growth by ____________________, the process that converts ____________ _____________ to the chemical _______________ of ____________________.
photosynthesis, light energy, energy, sugar
What do __________________ bacteria have?
photosynthetic bactria in-folded regions of the plasma membrane containing clusters of pigments and enzymes. (they don't have chloroplasts) ---->don't have an organelle but they have a region
What are the two photosystems?
photosystem I and II Two types of photosystems (photosystem I and photosystem II) cooperate in the light reactions. Each photosystem has a characteristic reaction-center complex, with a special pair of chlorophyll a molecules associated with a particular primary electron acceptor.
Chloroplasts contain several different _________________.
pigments
What is the ultimate source of food for other organisms?
plants
WHat do ATP and NADPH do after the light reaction?
power sugar synthesis in the Calvin cycle
Electromagnetic energy travels in ______________.
waves
Where does the Calvin cycle occur?
stroma of the chloroplast
The Calvin cycle makes _________ within a chloroplast.
sugar
Photosynthesis makes _________ from ________ and ________, providing food and O2 for almost all living organisms
sugar, CO2, H2O
After carbon fixation, the carbon compounds are reduced to ____________.
sugars
Chromeophyll-
takes place of chlorophyll during the fall since we are away from the sun
Wavelength-
the distance between the crests of two adjacent waves
What does light energy absorbed by the two photosystem drive?
the flow of electrons from water to NADPH
Where do the light reactions occur?
thylakoid membrane
Stomata-
tiny pores in the leaf that allow carbon dioxide to enter and oxygen to exit.
We see the color of the wavelengths that are...
transmitted
Poison contains _____________, a chemical that may cause itchy and oozing blisters that can last weeks.
uroshiol
Photoautotrophs-
use the energy of light to produce organic molecules
What do sugars also serve as?
✩Sugars also serve as the starting material for making other organic molecules, such as proteins, lipids, and cellulose. Many glucose molecules are linked together to make cellulose, the main component of cell walls. Plants store it as starch or glycogen in human
