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120 Cards in this Set
- Front
- Back
Magnification |
"Make bigger" - depth |
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Resolution |
"Make clearer" - clarity |
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Electron Microscope |
Could magnify 7000x. Use beams of electrons instead of light. |
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Name two types of lenses found in a compound microscope |
objective and ocular |
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objective lens |
the lens closest to the specimen in the microscope. Objective forms the initial image. |
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ocular lens |
the eyepiece where we look in to view the specimen under the microscope. The ocular lens magnifies the image and collects it. |
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iris diaphragm |
In a compound microscope - controls the amount of light reaching the specimen. Helps control the focus. Located above the condenser and below the stage. |
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Condenser |
Condenser is a set of lenses that focuses the light through the specimen into the objective lens in a compound microscope |
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What is the best way to avoid breaking a slide when using a compound light microscope? |
Start viewing the specimen at low magnification, use coarse and then fine focus to see the image clearly and then switch to higher magnification. Once you are at higher magnification, do not focus using the coarse focus knob, only the fine focus knob. |
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As you magnify an image, the diameter of the field of view increases or decreases? |
decreases |
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Confocal microscope |
forms image of small things - like a cell |
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Transmission electron microscope (TEM) |
forms an image from electrons passing through a specimen |
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Light microscope |
an instrument that uses visible light and magnifying lenses to examine small objects not visible to the naked eye, or in finer detail than the naked eye allows. |
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Scanning electron microscope |
an electron microscope in which the surface of a specimen is scanned by a beam of electrons that are reflected to form an image. |
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Dissecting microscope |
optical microscope variant designed for low magnification observation of a sample, typically using light reflected from the surface of an object rather than transmitted through it. |
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chromosome |
circular shape, consists of a DNA molecule, and small number of proteins |
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Gene |
Gene = segment of DNA that contains information for building the RNA molecule or a polypeptide |
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nucleoid (prokaryote) |
is where DNA is contained in a single, condensed, circular chromosome. |
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Eubacteria and Archaebacteria are prokaryotes, which means? |
They have no nucleus and generally no membrane-bound organelles |
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cell membrane (prokaryote) |
Cell membrane which as for all cells controls what enters or leaves the cell. |
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Cytoplasm (prokaryote) |
contains enough proteins and other molecules for the cell’s functions. |
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plasmids (prokaryote) |
Plasmids which are small circular pieces of chromosome in most prokaryotes. |
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Ribosomes (prokaryote) |
Ribosomes which help produce the proteins within the cytoplasm. |
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Cell wall (prokaryote) |
Cell wall which is a tough fibrous layer that surrounds the plasma membrane and functions to protect and give shape to the cell. (See Figure 7.5 in your textbook.) |
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flagella (prokaryote) |
Flagella which are thin extension of the cell and lack a membrane covering. Flagella rotate to provide locomotion. Not all prokaryotes have flagella. |
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cytoskeleton (prokaryote) |
Cytoskeleton which are long thin protein fibres inside the cell. The cytoskeleton fibres help with cell division and help maintain cell shape. |
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Eukaryotes |
Have a nucleus and membrane bound organelles. |
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endoplasmic reticulum (ER) (eukaryote organelle) |
continuous with an extensive series of membrane-bound sacs. The ER extends from the nuclear envelope out into the cytoplasm. knobby looking structures are ribosomes that attach to the membrane. They synthesize proteins that will be inserted into the plasma membrane, secreted to the cell exterior, or shipped to an organelle. |
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golgi body (eukaryote organelle) |
- Stack of flat, membrane-bounded sacs - Involved in secretion -
Involved in modifying proteins and lipids |
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lysosome (eukaryote organelle) |
= digestive Center.
The organelles interior, or lumen, is acidic because proton pumps in the lysosome membrane import enough hydrogen ions to maintain a pH of 5.0 Contain 40 enzymes |
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vacuole (eukaryote organelle) |
Contains transporters for selected molecules acts as storage unit for oils, carbs, water, or toxins |
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mitochondria (eukaryote organelle) |
oxidation-reduction reactions, ATP synthesis - Bound by a double membrane - Inner membrane is folded into cristae - ATP is made here
- Contains its own genetic material |
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chloroplast (eukaryote organelle) |
production of ATP in plants through photosynthesis |
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peroxisomes (eukaryote organelle) |
oxidation of fatty acids - Roughly spherical - Bound by a single membrane - Filled with enzymes, predominately catalase (breaks down H2O2) -
Involved with oxidation of fatty acids |
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Difference between Rough ER and Smooth ER |
Rough ER has ribosomes and functions primarily as a protein-manufacturing Centre Smooth ER lacks ribosomes and functions primarily as a lipid-processing Centre. |
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flagella + cilla |
like a tail propelling through water. when present in the plasma membrane their rotation allows aquatic cells to swim through the water. Can move the cell quickly. |
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If you place an animal cell in a hypotonic solution, you would expect the cell to...? |
lyse |
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active transport requires (3)? |
1. specific membrane proteins. 2. changes in conformation 3. ATP |
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actin |
major protein in Microfilaments |
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keratin |
major protein in intermediate filaments |
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α and β tubulin |
major protein in microtubules |
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Tight junction |
Tight Junction = a cell-cell attachment composed of specialized proteins in the plasma membranes of adjacent animal cells. (ex. looks like quilting). Watertight seal, this type of junction is found in cells that form a barrier - such as epithelial cells lining your stomach and intestines. They can loosen for specific purposes and then retighten later - this makes them dynamic. |
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Desmosomes |
Desmosomes = cell-cell attachements particularly common in animal epithelial cells and certain muscle cells. (ex. rivets that hold pieces of sheet metal together). Proteins that bind together the cytoskeletons of adjacent cells. |
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Tight junction facts (4) |
1 Found in animal tissues. 2 Found in tissues lining internal cavities +organs. 3 They seal adjoining cells. 4 Tight junctions allow for communication and coordination between adjacent cells. |
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phophorylation cascade |
A phosphorylation cascade is a type of signal transduction pathway in which a series of molecules are phosphorylated in turn. |
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How can two cells have different responses to a signal? |
Different cells possess different collections of proteins that allow for alternate signal transduction pathways and, as such, variable responses. |
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Signal Transduction Pathway |
binding of a signal molecule to a membrane signal receptor causes a conformational or shape change, which can then set off a chain reaction known as a signal-transduction pathway. |
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second messengers |
when a signal molecule binds to a plasma membrane receptor the change in the shape of the receptor triggers the formation of many second messengers—small non-protein molecules or ions that can diffuse quickly in a cell. |
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phosphorylation |
phosphorylation = addition of a phosphate group to a substrate |
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exergonic |
release of energy (exer - like exit) |
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endergonic |
absorption of energy |
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redox reaction (reduction, oxidation) reaction |
redox reaction (reduction, oxidation) = the loss or gain of one electron. An electron can be transferred completely from one atom to another, or an electron can simply shift its position in a covalent bond |
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electron carrier |
electron carrier = when something donates electrons to other molecules - has reducing power (ex. NADH) |
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How does free energy synthesize ATP? |
in cells, the change in free energy that occurs during the oxidation of glucose is used to synthesize ATP from ADP and P. |
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What macromolecule is ATP? |
= ATP is a nucleotide as it has nitrogenous base, a sugar (ribose) and phosphate groups. |
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ATP |
- high potential energy - not stored - glucose makes ATP through photosynthesis - when coming from a plant it goes back into glucose and then once inside our bodies, glucose turns it back into ATP (it does this through cellular respiration OR fermentation |
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cellular respiration |
Reactions that produces ATP in an electron transport chain (a process to produce ATP from glucose.) |
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Name the four steps of cellular respiration |
1. substance with high potential energy (glucose) does glycolysis 2. pyruvate processing 3. citric acid cycle (Krebs?) 4. electron transport and chemiosmosis |
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Fermentation |
allows glycolysis to produce ATP in the absence of the electron acceptor required by the ETC. |
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ATP made by these two processes in cellular respiration: |
1. oxidative phosphorylation 2. Substrate-level phosphorylation |
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Substrate-level phosphorylation |
occurs when a phosphate group from a substrate is directly transferred to ADP, resulting in ATP |
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oxidative phosphorylation |
occurs when ATP is made indirectly through the energy released from oxidation reactions |
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Glycolysis occurs where? |
glycolysis occur in the cytosol. ATP molecules are needed at the start to produce more ATP in this reaction. results in ATP and NADH |
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citric acid cycle |
circular not linear cycle - It starts with citrate which becomes citric acid when protonated. |
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Electron Transport Chain |
A series of redox reactions, during which electrons are passed from one compound to another compound that is more electronegative. As the electrons are passed down the chain, energy is gradually released and ultimately is used to make ATP through a process called chemiosmosis and oxidative phosphorylation |
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Electrochemical gradient |
Trying to get protons back into the matrix |
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Chemiosmosis |
when protons move through ATP synthase, the protein spins and generates ATP. |
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ATP synthase |
A large membrane-bound protein complex in chloroplasts, mitochondria, and some bacteria that uses the energy of protons flowing through it to synthesize ATP. |
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aerobic respiration |
organisms that need oxygen as an electron acceptor for the ETC |
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anaerobic respiration |
organisms that depend on electron accepters other than oxygen. |
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most of the work in cells are endergonic or exergonic? |
endergonic. They absorb energy. That's why ATP is needed to drive it. |
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glycolysis |
10 step reaction where glucose is broken into pyruvate |
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pyruvate processing |
converts pyruvate into acetyl CoA. |
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Citric Acid Cycle |
8 step reaction cycle that begins with acetyl CoA and ATP is produced and CO2 is released. Occurs in the matrix of mitochondria in eukaryotes. |
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Feedback inhibition |
How ATP is regulated. Occurs when an enzyme in a pathway is inhibited by the product of the reaction sequence. The product molecule “feeds back” to stop the reaction sequence when the product os abundant. Meaning - if there is enough ATP at the time, then the body will store the glucose for when they really need ATP and its scarce. |
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chemiosmotic hypothesis |
Electron transport chains generate ATP indirectly, by the creation of a proton-motive force. |
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What is the function of a fermentation pathway? |
to generate NAD+ from NADH, so that glycolysis can continue |
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Per Krebs cycle how much ATP is produced and how much NADH is produced? |
2 ATP; 3 NADH |
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In the electron transport chain, what is the final electron acceptor? |
oxygen |
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Something is embedded in the ETC in the cristae or inner membrane... what is it? |
The components of an electron transport chain consist of a series of enzyme complexes embedded in the cristae or inner membrane folds of mitochondria. There are many such chains in a single mitochondrion. |
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isomer |
An isomer = a compound that has the same molecular formula but a different structural formula. |
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where does the phosphate come from? |
The phosphate comes from the substrate of the reaction. |
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Name some electron donors in the ETC |
Both NADH and FADH2 act as electron donors in the electron transport chain. |
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Phospholipids can form all of the following structures in water except which one? |
monolayers |
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Photosynthesis |
Conversion of light energy to chemical energy stored in the bonds of carbohydrates. |
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compartments in the chloroplast |
grana and thylakoid |
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Calvin Cycle |
the reactions that reduce carbon dioxide and produce sugar. Starts with enzyme rubisco, which catalyzes the addition of CO2 to a five-carbon compound. Subsequent reactions use ATP and NADPH synthesized in the light reactions and make carbs. |
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Two linked set of reactions from photosynthesis: light capturing and the other calvin cycle - describe what they do..? |
two linked sets of reactions = one triggered by light and one by the calvin cycle (which requires the products of the light capturing reactions). The light capturing reactions produce oxygen from water, the Calvin cycle produces sugar from CO2. |
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photon |
photons = a discrete packet of light energy; a particle of light |
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chlorophylls |
chlorophylls = absorb blue and red regions of the visible spectrum. This makes plants look green because they reflect and transmit green instead of absorbing it. |
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carotenoids |
carotenoids = absorb in the blue and green parts of the visible spectrum. |
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If chlorophylls is the main thing in photosynthesis, then what do carotenoids do? |
They quench free radicals by accepting or stabilizing unpaired electrons. They protect chlorophyll molecules from harm. |
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fluoresence |
fluorescence = when the excited electron simply falls back to its ground state, and some of the absorbed energy is released as heat and the rest is released as electromagnetic radiation (light). |
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photosystem |
photosystem = one of two types of units, consisting of a central reaction centre surrounded by antenna complexes, that is responsible for the light-depend reactions of photosynthesis |
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What is the photosynthesis reaction? |
6CO2 + 12H2O + light energy → C6H12O6 + 6O2 + 6H2O |
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antenna complex |
antenna complex = when a red or blue photon strikes a pigment molecule in the antenna complex the energy is absorbed and an electron is excited in response. This energy - but not the electron itself - is passed to a nearby chlorophyll molecule, where another electron is excited in response. |
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reaction centre |
reaction centre = excited electrons are transferred to a specialized chlorophyll molecule that acts as an electron acceptor. |
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photosystem 1 |
photosystem 1 = a photosystem that contains a pair of P700 chlorophyll molecules and uses absorbed light energy to produce NADPH |
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photosystem 2 |
photosystem 2 = a photosystem that contains a pair of P680 chlorophyll molecules and uses absorbed light energy to split water into protons and oxygen and to produce ATP. |
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photophosporylation |
photophosporylation = the production of ATP molecules using the energy released as light-excited electrons flow through an electron transport chain during photosynthesis. Involves generation of a porton-motive force during electron transport and its use to drive ATP synthesis. |
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cyclic-photophosphorylation (cyclic electron flow) |
cyclic-photophosphorylation = path of electron flow during the light-dependent reactions of photosynthesis in which photosystem 1 transfers excited electrons back to the electron transport chain of photosystem 2, rather than to NADP+. Also called cyclic electron flow. Generates ATP but doesn't produce NADPH. |
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Z scheme (non cyclic electron flow) |
non-cyclic electron flow = path of electron flow in which electrons pass from photystem 2 to photosystem 1 and ultimate to NADP+ during the light-dependent reactions of photosynthesis. Originally called the Z scheme. |
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resonance |
transfer of energy among pigment molecules |
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photorespiration |
occurs when levels of CO2 are low and O2 are high. Less sugar is produced. |
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what happens when an excited electron is passed to an electron acceptor in a photosystem? |
energy in sunlight is transformed to chemical energy |
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In PS 2 light energy is converted into chemical energy |
when excited electrons from the reaction centre are accepted by pheophytin, reducing it. |
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in PS 1 light energy is converted into chemical energy |
when excited electrons from the reaction centre are accepted by ferredoxin. |
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How many molecules of water are needed to make a single molecule of glucose? |
6 molecules of water. |
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Carbon Fixation |
the initial incorporation of CO2 into an organic compound. |
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For every glucose molecule being made by a plant, how many rounds of the Calvin cycle are necessary? |
6 |
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How does P680 replace its lost electrons? |
P680 replaces its electrons by oxidizing water. This “splits” the water molecule, to supply electrons. |
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How does P700 replace its lost electrons? |
P700 replaces its electrons by accepting the electron from the electron transport chain initiated by photosystem II. |
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ATP generated by the passing of electrons from photosystem II to photosystem I is made through chemiosmosis. True or false. |
True |
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Where do the products of noncyclic electron flow ultimately go? |
the calvin cycle |
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What is the purpose of the cyclic electron flow? |
Because the Calvin cycle consumes more ATP than NADPH, cyclic electron flow allows the plant to keep the Calvin cycle running without accumulating NADPH. |
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G1 - checkpoint 1 |
checking if it has sufficient nutrients, cell size, lack of DNA damage, and or social signals |
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G2 - checkpoint 2 |
delays progress until chromosome replication is complete and any damaged DNA that is present is repaired |
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M phase - checkpoint 3 |
delays anaphase until all chromosomes are correctly attached to the spindle apparatus |
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Name two regulators |
Cyclins and cyclin-dependeant kinases; they may help phosphorylate proteins required for the next cell-cycle phase |
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cancer is characterized by |
1) loss of control at the G1 checkpoint 2) metastasis - tumours spreading thru the body |