Photosynthesis and Cellular Respiration Test
As in photosynthesis, the cell uses a process known as __________________ to produce ATP.
chemiomosis
How is the energy provided by ATP used?
Cells use it carry out active transport ATP powers movement, providing the energy for motor proteins that contract muscle and power the wavelike movement of cilia and flagella. It also powers important events in the cell like the synthesis of proteins, responses to chemical signals at the cells surface, and producing light.
Where does electron transport occur?
cristae
Where does glycolysis occur?
cytoplasm
Where does cellular respiration occur?
cytoplasm and mitochondria
What are stomata and why are they important?
Stomata are the pores on the underside of plants that are used for gas exchange. They are powered by turgor pressure, and allow the reactants for cellular processes to enter into the leaf.
Where does the energy for photosynthesis come from?
Sunlight
Why is the ATP production from cellular respiration important?
The ATP provides the cells with the energy that they need to function.
What is transpiration?
The loss of water vapor through the stomata of leaves.
ATP can easily release and store energy by ________________________________________________. This characteristic of ATP makes it exceptionally useful as a basic energy source for all cells.
breaking and reforming the bonds between its phosphate groups
Where do living things get the energy they use to produce ATP?
chemical compounds known as food
What are the steps of cellular respiration?
*Cellular respiration is the process that releases energy from food in the presence of oxygen* Cellular respiration captures the energy in 3 main stages: Glycolysis, the Krebs Cycle, and the Electron Transport Chain.
What happens in glycolysis?
*During glycolysis, 1 molecule of glucose, a 6-carbon compound, is transformed into 2 molecules of pyruvic acid, a 3-carbon compound. As the bonds in glucose are broken and rearranged, energy is released.* 2 ATP molecules are used in the beginning to get glycolysis going and overall, 4 ATP molecules a produced for a profit of 2 ATP per molecule of glucose. In the process of glycolysis, 4 ATP molecules are synthesized from 4 ADP molecules. *"Energy Investment"* 2 ATP used to make 2 ADP *"Energy Payoff"* 4 ADP and 2NAD forms 4 ATP and 2NADH *"Profit"* 2 ATP, 2 NADH, 2 Pyruvate produced
What happens in the Calvin cycle of photosynthesis?
*During the Calvin cycle, plants use the energy that ATP and NADPH contain to build stable high-energy carbohydrate compounds (sugars) that can be stored for a long time* *Carbon Dioxide Enters the Cycle* 6 carbon dioxide molecules from the air are combined with 6 five-carbon molecules which produce 12 three-carbon compounds. Other enzymes use energy from ATP and high-energy electrons from NADPH to convert these compounds into higher-energy forms in the rest of the cycle. *Sugar Production* Midway through, 2 of the 12 three-carbon molecules are removed from the cycle because they become the building blocks the plant cell uses to produce sugars, lipids, amino acids, and other compounds. The remaining 10 three-carbon molecules are converted back into 6 five-carbon molecules, which then combine with 6 new carbon dioxide molecules to begin the next cycle. *Summary* Calvin cycle uses 6 molecules of carbon dioxide to produce a single 6-carbon sugar molecule with energy from compounds produced in light-dependent reactions. These sugars are used by the plant to meet its energy needs and build macromolecules for growth and development.
What happens in the Krebs cycle?
*During the Krebs cycle, pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions.* Each turn of the cycle converts a molecule of ADP into ATP. Glycolysis makes 2 molecules of pyruvic acid from 1 molecule of glucose so the Krebs cycle takes the glucose in 2 turns and therefore, 2 ATP. Energy released by the breaking and rearranging of carbon bonds is captured in the forms of ATP, NADH, and FADH. Carbon dioxide isn't useful to cell so it's released whenever you exhale. The ATP molecules are very useful and immediately become available to power cellular activity. High-energy electron carriers like NADH, in the presence of oxygen, the electrons they hold are used for generating large amount of ATP.
What are the steps in photosynthesis?
*Photosynthesis uses the energy of sunlight to convert water and carbon dioxide (reactants) into high-energy sugars and oxygen (products).* Photosynthesis involves two sets of reactions. The first set of reactions is known as the *light-dependent reactions* because they require the direct involvement of light and light-absorbing pigments. The light-dependent reactions use energy from sunlight to produce energy-rich compounds such as ATP. These reactions take place in the thylakoid membranes of the chloroplasts. Water is required in these reactions as a source of electrons and hydrogen ions. Oxygen is released as a byproduct. Plants absorb carbon dioxide from the atmosphere and complete the process of photosynthesis by producing carbon-containing sugars and other carbohydrates. During the *light-independent reactions*, ATP and NADPH molecules produced in the light-dependent reactions are used to produce high-energy sugars from carbon dioxide. The light-independent reactions take place outside the thylakoids, in the stroma.
What happens in the electron transport system?
*The electron transport chain uses the high-energy electrons from glycolysis and the Krebs cycle to convert ADP into ATP* *Electron Transport* NADH from glycolysis joins NADH and FADH from the Krebs cycle to pass their electrons to the ETC. High-energy electrons are passed from one carrier to the next and at the end, an enzyme combines the electrons with hydrogen ions and oxygen to form water. Every time 2 high-energy electrons pass down the ETC, their energy is used to transport hydrogen ions across the membrane. During ETC, those ions build up in the intermembrane space, making it positively charged relative to the matrix. The matrix side is negative as a result. *ATP Production* The inner mitochondrial membrane contains enzymes known as ATP synthases. The charge difference across the membrane forces positive H ions through channels in these enzymes, causing the ATP synthases to spin. Each rotation, the enzyme grabs an ADP molecules and attaches a phosphate group, producing ATP. The ions rush back across the membrane with enough force to spin the ATP synthase and generate large amount of ATP. On average, each pair of high-energy electrons that moves down the full length of the electron transport chain provides enough energy to produce 3 molecules of ATP.
What happens in the light phase of photosynthesis?
*The 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 occur in the thylakoids of chloroplasts. -Thylakoids have clusters of chlorophyll and proteins known as photosystems, which are essential to these reactions Photosystems absorb sunlight and generate high-energy electrons that are passed to a series of electron carriers in the thylakoid membrane. *Photosystem II* Light energy absorbed by photosystem II produces high-energy electrons. Water molecules are split to replace those electrons, releasing H ions and oxygen. *Electron Transport* High-energy electrons move down the electron transport chain, to photosystem I. Energy generated is used to pump H ions across the thylakoid membrane and into the thylakoid space. *Photosystem I* Electrons are reenergized in photosystem I. A second electron transport chain then transfers these electrons to NADP, producing NADPH. *Hydrogen Ion Movement and ATP Formation* As the thylakoid space fills up with positively charged H ions, the inside of the thylakoid membrane becomes positively charged relative to the outside of the membrane. H ions pass back across the thylakoid membrane through ATP synthase. As the ions pass through, the ATP synthase molecule rotates and the energy produced is used to convert ADP to ATP.
How much ATP does anaerobic respiration produce?
2 ATP
How much ATP does cellular respiration produce?
36 ATP
What is the chemical reaction formula for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2
What is the chemical reaction formula for cellular respiration?
6O2 + C6H12O6 → 6CO2 + 6H2O + ENERGY
A single molecule of the sugar glucose stores more than ____ times the energy required to add a phosphate group to ADP to produce ATP.
90
Alcoholic Fermentation
A process used by yeast cells and some bacteria to produce carbon dioxide and ethyl alcohol. Pyruvic acid + NADH → Alchohol + CO2 + NAD
What chemical is considered the chemical "battery" for cellular processes?
ADP (adenosine diphosphate) or ATP (adenosine triphosphate)
When a cell generates large amount of ________ from glycolysis, it runs into a problem.
ATP In a few seconds, all the cell's available NAD molecules are filled up with electrons. Without oxygen, the ETC doesn't run, so there's nowhere for NADH molecules to deposit their electrons. NADH doesn't get converted back into NAD and without NAD, the cell can't keep glycolysis going, and ATP production stops. This is where fermentation comes in.
calorie
Amount of energy needed to raise the temperature of 1 gram of water through 1 degrees Celsius
Why do we see different colors? (How does color "work"?)
Energy from the sun travels to Earth in the form of light. We see sunlight as white light but it's a mixture of different wavelengths. The wavelengths that we can see make up the visible spectrum which includes shades of red, orange, yellow, green, blue, indigo, and violet. When we look at something, we see all the wavelengths aren't absorbed and reflected back at us because all the other wavelengths are absorbed.
Where is the energy stored in ATP and ADP?
Energy is stored in the bond that is found between the 2nd and 3rd phosphate groups.
What are the parts of mitochondria?
Folds increase surface area. Mitochondria has DNA and can reproduce itself. If more energy is needed, mitochondria will reproduce.
Products and reactants of the stages of cellular respiration
GLYCOLYSIS *Reactants:* 2 ATP, Glucose *Products:* 2 ATP, 2 NADH, 2 Pyruvic Acid KREBS CYCLE *Reactants:* 2 Pyruvic Acid *Products:* Carbon Dioxide, ATP, NADH, FADH ELECTRON TRANSPORT CHAIN *Reactants:* NADH, FADH *Products:* ATP, Water
What is the main chemical for storing energy made by plants?
Glucose
Where in the leaf does photosynthesis occur?
Inside organelles called chloroplasts
Why do most cells only have a small amount of ATP?
It's not a good way to store large amounts of energy. Cells can regenerate ATP from ADP as needed by using energy in foods like glucose.
Which processes require oxygen?
Krebs cycle and electron transport
Products and reactants of the stages of photosynthesis
LIGHT-DEPEDENT REACTIONS *Reactants:* 6H20 *Products:* 602 CALVIN CYCLE *Reactants:* 6CO2 *Products:* C6H12O6
Why are leaves green?
Leaves reflect green light, which is why plants look green. Plants also have red and orange pigments (carotene) that absorb lights in other regions of spectrum but most of the time, the intense green color of chlorophyll overpowers these pigments. As temperatures drop, chlorophyll molecules break down first and reveal the red and orange of the accessory pigments.
Lactic Acid Fermentation
Most organisms carry out fermentation using a chemical reaction that converts pyruvic acid to lactic acid. Unlike alcoholic fermentation, lactic acid fermentation doesn't give off carbon dioxide. Lactic acid can be sent to the liver for conversion to glycogen which can be used to start cellular respiration. Pyruvic acid + NADH → Lactic acid + NAD
Autotrophs
Organisms that make their own food -Nearly all life on Earth, including us, depends on the ability of autotrophs to capture the energy of sunlight and store it in the molecules that make up food
Heterotrophs
Organisms that obtain food by consuming other living things -some get food by eating plants like grasses -some get food indirectly by feeding on plant-eating animals -some absorb nutrients from decomposing organisms in the environment
What is the most important product of photosynthesis?
Oxygen
What happens after glycolysis if there is no oxygen?
Oxygen is required at the very end of the electron transport chain. Any time a cell's demand for energy increases, its use of oxygen increases, too. When oxygen is absent, the cell undergoes a process called fermentation.
Photosynthesis
The process by which autotrophs use energy of sunlight to produce high-energy carbohydrates --sugars and starches-- that can be used as food In the process of photosynthesis, plants convert the energy of sunlight into chemical energy stored in the bonds of carbohydrates.
How are photosynthesis and cellular respiration related and how are they different?
Photosynthesis creates glucose while cellular respiration breaks apart glucose. Photosynthesis stores energy while cellular respiration releases energy. Photosynthesis takes place in the chloroplast while cellular respiration takes place in the cytoplasm and mitochondria. Photosynthesis is comprised of a light-dependent reaction and Calvin cycle while cellular respiration has glycolysis, the Krebs cycle, and the electron transport chain. Photosynthesis uses carbon dioxide while cellular respiration releases carbon dioxide. Photosynthesis releases oxygen while cellular respiration uses oxygen. Photosynthesis is used by plants and other autotrophs whole cellular respiration is used by heterotrophs and plants (plants still need to break down glucose). The products of one reaction are the reactants of the other.
What is fermentation?
When oxygen is not present, glycolysis is followed by a pathway that makes it possible to continue to produce ATP without oxygen. The combined process of this pathway and glycolysis is called fermentation. *In the absence of oxygen, fermentation releases energy from food molecules by producing ATP.* During fermentation, cells convert NADH to NAD by passing high-energy electrons back to pyruvic acid. This converts NADH back to NAD allowing glycolysis to function. Fermentation is an anaerobic process that occurs in the cytoplasm of cells.
An _________ _________ is a compound that can accept a pair of high energy electrons and transfer them, along with most of their energy, to another molecule
electron carrier One of these carrier molecules is *NADP*. -it accepts and holds 3 high-energy electrons, along with a hydrogen ion which converts it into NADPH -conversion is one way that some sunlight energy can be trapped in chemical form -NADPH can carry high-energy electrons that were produced by light absorption in chlorophyll to chemical reactions elsewhere in the cell -high-energy electron carriers used to help build molecules that the cell needs, including glucose
In __________, the electron transport chain is composed of a series of electron carriers located in the inner membrane of the mitochondrion. In ________, the same chain is in the cell membrane.
eukaryotes, prokaryotes
Although the energy yield from glycolysis is small, the process is so ______ that cells can produce thousands of ATP molecules in just a few milliseconds.
fast The speed of glycolysis can be a big advantage when the energy demands of a cell suddenly increase. Besides speed, another advantage of glycolysis is that the process itself does not require oxygen. This means that glycolysis can quickly supply chemical energy to cells when oxygen is not available.
Humans are ___________________ fermenters
lactic acid During brief periods without oxygen, many of the cells in our bodies are capable of producing ATP by lactic acid fermentation. The cells best adapted to doing that are muscle cells, which often need very large supplies of ATP for rapid bursts of energy.
What are the byproducts of anaerobic respiration?
lactic acid or ethanol
Energy comes in many forms including:
light, heat, and electricity. it can also be stored in chemical compounds
Where does the Krebs cycle occur?
matrix of mitochondria
Without the ability to ________ ______ _______ ________, life would cease to exist.
obtain and use energy
structure of chloroplast
organelle for photosynthesis has double membrane contains discs called thylakoids thylakoids contain chlorophyll stack of thylakoids called granum thylakoids surrounded by a fluid called stroma
_______________ serves as the final electron acceptor of the electron transport chain.
oxygen Oxygen is essential for getting rid of low energy electrons and hydrogen ions, the wastes of cellular respiration. Without oxygen, the electron transport chain cannot function.
Photosynthetic organisms capture energy from sunlight with ____________.
pigment The plants' principal pigment is chlorophyll. The two types of chlorophyll found in plants, chlorophyll a and chlorophyll b, absorb light very well in the blue-violet and red regions of the visible spectrum. Chlorophyll doesn't absorb light well in the green region of the spectrum.
Among the most important factors that affect photosynthesis are ___________, ______ ________, and ____________________________
temperature, light intensity, the availability of water photosynthesis occurs by enzymes that function best between 0 and 35 degrees Celsius -very low temperature may stop photosynthesis entirely high light intensity increases the rate of photosynthesis but after it reaches a certain level, the plant maxes its rate a shortage of water can slow or stop photosynthesis by damaging tissues
What part of cellular respiration requires oxygen?
the Krebs cycle and electron transport chain They are both *aerobic* processes which means pathways of cellular respiration that require oxygen. The Krebs cycle doesn't directly require oxygen but it cannot run without the oxygen requiring electron transport chain. Glycolysis is *anaerobic* meaning it doesn't directly require oxygen, nor does it require on an oxygen-requiring process to run.
Energy
the ability to do work
ATP is a great molecule for _____________ ________, it is not a good one for storing large amounts of energy over the long term.
transferring energy
