Term
| -what is membrane fluidity/ what does it mean? |
|
Definition
| -membrane fluidity is the extent to which phospholipids can move horizontally within the membrane. (Usually phospholipids can do this unless they are hooked onto something like a protein or ECM) |
|
|
Term
| What affects membrane fluidity? |
|
Definition
| 1. the types of lipids present , 2. the length of the fatty acid (the shorter the more fluid), 3. the amount of saturation of the fatty acid (more unsaturated fatsà more fluid membrane), and , 4.the addition of cholesterol (up to a certain amount it makes the membrane more fluid, but beyond that threshold it becomes rapidly less fluid) |
|
|
Term
| What did Frye and Edidin show? |
|
Definition
| -they made antibodies that recognized human protein on cells. Then they fused two cells and the molecules dispersed and showed lots of fluidity in the plane. So they demonstrated protein fluidity within the membrane. |
|
|
Term
| What is the ratio of proteins and lipids in the membrane? |
|
Definition
|
|
Term
| What does the fluid mosaic model try to explain? |
|
Definition
| -that the membrane is a “mosaic” of proteins floating in a “sea” of lipids |
|
|
Term
| What are the different kinds of proteins present in the membrane? |
|
Definition
| peripheral proteins that are situation on one side of the membrane; -integral proteins that cross the membrane. |
|
|
Term
| What is a distinctive component of a peripheral protein’s structure? |
|
Definition
| -whenever sugar molecules are attached to a peripheral protein they face OUT of the cell since they are used for identification purposes. They NEVER face in. |
|
|
Term
| What is freeze fracture microscopy and what is it used for? |
|
Definition
| -it is when a cell is frozen and the outer membrane in chipped off leaving the inner layer exposed. It is used because then it is much easier to see what’s on the inside and what’s on the outside and to look at the many embedded integral (aka transmembrane proteins) |
|
|
Term
| What is distinctive about integral a.k.a. transmembrane protein’s structure? |
|
Definition
| -the part of the protein that is in the membrane is made up of hydrophobic amino acids that are attached to (usually) an alpha helix protein structure. This structural component helps the protein helps it stay in place because it wants to stay with the hydrophobic fatty acid tails, these hydrophobic groups do NOT want to interact with the water in the cytoplasm. Breaking up cells has a bad effect on transmembrane proteins. |
|
|
Term
| What are the 4 kinds of trans-membrane proteins? |
|
Definition
| transporters, linkers, receptor proteins, enzymes |
|
|
Term
| What do transport trans-membrane proteins do? |
|
Definition
| -they are embedded into the cell membrane in order to provide a specific channel that certain molecules can pass through |
|
|
Term
| What do linker trans-membrane proteins do? |
|
Definition
| -they hook onto fibers on either side of the membrane, ex. Protein integrin |
|
|
Term
| What do we call the molecules that bind to receptor proteins? |
|
Definition
|
|
Term
| What do receptor proteins do? |
|
Definition
| -A ligand binds to protein which passes a signal along (but not the ligand itself) that lets the cell know the signal has arrived “I’ve got one.” Then the receptor may change shape or activate a nearby enzyme because of the signal from the ligand. Receptor proteins are ligand-specific, ex. a steroid receptor will bind to testosterone. |
|
|
Term
| What are acqueous pores? (structure and function) |
|
Definition
| -they are a pore formed by a single protein that has 5 alpha helix regions embedded in the membrane. The hydrophobic side chains face out towards the membrane and hydrophilic side chains face in. Func: the pore lets sugars and ions enter the cell that do not want to interact with the hydrophobic membrane. |
|
|
Term
| What are the main protein lines in the cytosol made of? |
|
Definition
|
|
Term
| What is the area of fibrous density just inside the cell membrane called? |
|
Definition
|
|
Term
| How do the proteins link to the molecules in the cytosol? |
|
Definition
| -they link to an attachment protein that is linked to an actin protein that is hooked onto the spectrin. |
|
|
Term
| What is the glycocalyx? What is it’s structure, function and location? |
|
Definition
| -the Glycocalyx is literally a “sugar halo.” Str: it is made up of oligosaccharides linked to membrane components Func: the sugars are used as ID markers, ex. to tell the cell that certain molecules do or don’t belong in the body. The ID is based on the kind and sequence of sugars used and each species has specific markers. Ex. in medicine porcine valve implant—have to remove sugars for a human body to accept otherwise will realize that the sugars coating the valve do not correspond to human cells. Loc: it covers the exterior of the cell membrane |
|
|
Term
| What are the 4 things that prevent proteins from moving freely in the membrane? |
|
Definition
| 1. Being tethered to the cell cortex 2. Being attached to the ECM (extracellularmatrix) 3.If they are tethered to the proteins of another cell. 4, If they are restricted by barriers, ex. cell junctions in epithelial cells |
|
|
Term
| What is the main composition of the cell membrane on the outside, inside and in the membrane? |
|
Definition
| Inside: proteins In membrane: phospholipids, steroids, integral proteins Outside: sugars |
|
|
Term
| What can diffuse through a membrane? |
|
Definition
| -small hydrophobic molecules (ex. O2, dissolves in lipid bilayer); small uncharged polar molecules (ex. H20, glycerol that sneak through some openings in the cell) |
|
|
Term
| What cannot diffuse through a membrane? |
|
Definition
| -large uncharged polar molecules -ions *they both need help to cross the membrane |
|
|
Term
| What are the two ways that plants have evolved to a new kind of respiration in hot conditions? |
|
Definition
|
|
Term
| What is the major structural difference between C3 and C4 leaves in terms of where photosynthesis occurs? |
|
Definition
| -C3 cells have a layer of palisade mesophyll cells which is where most of photosynthesis occurs(check this). In c4 cells there is a thicker membrane so that CO2 can’t easily diffuse through the membrane and photosynthesis occurs in bundled sheath cells instead. |
|
|
Term
| What are the other main differences between C3 and C4 cells? |
|
Definition
| C4 cells have to spend extra ATP and have an additional chamber to create a 4 carbon compound by absorbing CO2 from the air in the mesophyll cell. That CO2 is then transferred, through 4C compounds,to the Calvin cycle which occurs in the bundle sheath cell. The bundled sheath cell is impervious to CO2 and there is no O2 in the cell, even in hot conditions so it does not act as a competitive inhibitor. Carbon binds in the regular way to enter the Calvin cycle. |
|
|
Term
| What are examples of C4 plants? |
|
Definition
| -Corn, sugarcane and crabgrass |
|
|
Term
| What are examples of CAM plants? |
|
Definition
| -cacti, pineapple, bromeliads (air plants that don’t need roots in their diet) |
|
|
Term
| Why are C3 and C4 leaves named the way they are? |
|
Definition
| -because in C3 leaves carbon is fixated onto a 3 carbon molecule, but in C4 leaves, carbon is fixated to a 4 carbon molecule |
|
|
Term
| How do CAM plants differ from C3 plants? |
|
Definition
| Unlike C4 plants, CAM plants do not have two chambers, however CAM plants are essentially a variation of C4 plants since the CO2 that enters these plants also becomes a 4 carbon molecule instead of a 3 carbon molecule. CAM plants work around photorespiration by separating the timing of the light and dark reactions. (**is this what they separate or is it again the 4 carbon thing—I’m confused) the C4 pathway is run at night when they open up the stomata, and then they run the calvin cycle in the day when the stomata are closed. |
|
|
Term
| What is the endosymbiont hypothesis? What does it try to explain? |
|
Definition
| The edosymbiont hypothesis is an explanation for the double membrane structure of chloroplasts and mitochondria. It theorizes that chloroplasts and mitochondria derive from ancient bacteria that were living isymbiotically inside another organism. i.e. instead of eating the bacteria, they cell kept it and harnessed the energy created by the bacteria |
|
|
Term
| What are the evidence scientists give to support this hypothesis? |
|
Definition
| Mitochondria and chloroplasts have maintained their double membrane structure. Their outer membrane is more cellular in structure and their inner membrane is more bacterial in structure., They do not have a nucleus. (original bacteria didn’t have one either), Small size, DNA present (makes sense if the original bacteria where an autonomous structure) and circular (typical of bacteria), In the “cytoplasm” of these original bacteria one can find metabolic enzymes (ex. Enzymes for glycolysis), Protein synthesis by small ribosomes (ribosomes in bacteria are noticeably smaller than those in eukaryotes), Genes: some have migrated from circles to nuclear DNA (in cell?) |
|
|
Term
| What is the name given to photosynthetic bacterium that gave rise to chloroplasts? |
|
Definition
|
|
Term
| How has the atmosphere changed over time? |
|
Definition
| -it used to be an oxidizing atmosphere with no oxygen, now it’s a reducing atmosphere with about 20% oxygen and most organisms are now dependent on oxygen. |
|
|
Term
| What are the two ways that glucose can be oxidated? |
|
Definition
| -it can be burned (all free E will be released as heat), OR -it can go through a stepwise oxidation so that some of the energy can be harnessed.Both result in CO2 and H2O |
|
|
Term
| What are the two basic ways to make ATP? |
|
Definition
| -Substrate level phosphorylation, Chemiosmotic synthesis of ATP |
|
|
Term
| What occurs in substrate level phosphorylation? |
|
Definition
| -ATP is made by an enzyme reaction using a high Energy phosphate bond of the substrate PEP-Pi to drive the formation of ATP. PEP-Pi has a very negative delta G, even more negative than ATP which is why it is used to drive the reaction. |
|
|
Term
| How is ATP made through chemiosmotic synthesis? |
|
Definition
| 1.H+ protons flow into the rotor of the ATP synthase enzyme and cause the head to turn, 2: As the head turns it phosphorylizes ADP into ATP. |
|
|
Term
| What is the part of the ATP synthase enzyme that is in the cell matrix? |
|
Definition
|
|
Term
| What is the part of the ATP synthase enzyme that is in the membrane? |
|
Definition
|
|
Term
| Where in the cell is ATP made and how? |
|
Definition
| -By glycolysis in the cell; By the oxidation of pyruvate to Acetyl CoA just inside the mitochondrial membrane; In the krebs cycle when Acetyl CoA becomes H2) and CO2 in the matrix of the mitochondria |
|
|
Term
| Which process yields the most ATP? |
|
Definition
| -The krebs cycle/oxidative respiration in general (though that would include the oxidation of pyruvate) |
|
|
Term
| What is the 1st law of thermodynamics? |
|
Definition
| -Energy is conserved, transferred, but never created or destroyed. |
|
|
Term
| What is the 2nd law of thermodynamics? |
|
Definition
| -the universe tends towards disorder,-heat is the least useful form of energy because it’s hard to harness |
|
|
Term
| Do Biologists see life as a violation of the 2nd law of Thermodynamics? |
|
Definition
| -No, biologists see life as an island of order in a sea of disorder. Life also produces heat that dissipates into the surroundings, so it contributes to the overall disorder of the universe. |
|
|
Term
| What is a ReDox reaction an example of? |
|
Definition
| -energy transfer, electron movement |
|
|
Term
| What is an enzyme cofactor? |
|
Definition
| -an enzyme cofactor is something that has to bind to the enzyme for it to work. Usually they are electron acceptors |
|
|
Term
| What is a common enzyme cofactor? |
|
Definition
|
|
Term
| What happens when NAD+ becomes NADH, is it oxidized or reduced? |
|
Definition
| -It gains energy and it is reduced. Remember, ReDox has to do with oxidation Numbers NOT charges. So if it gains an electron to become a neutral molecule it went from +1 to zero in terms of oxidation numbers so we say that it was reduced. |
|
|
Term
| What are the steps for NAD+ to become reduced to NADH? |
|
Definition
| -An energy-rich molecule with an H and NAD+ both bind to the enzyme. 2:A redox reaction takes place where an H atoms moves onto NAD+ so that it becomes NADH 3:NADH and the energy-rich molecule both diffuse away from the enzyme. |
|
|
Term
|
Definition
| -The amount of available energy to do work (i.e. energy that is not lost to heat) |
|
|
Term
|
Definition
| -Energy that is lost to heat |
|
|
Term
| What is an endergonic reaction? |
|
Definition
| -A reaction that needs energy in order to take place. It is energetically “unfavorable” so it will no go spontaneously |
|
|
Term
| What is an exergonic reaction? |
|
Definition
| -A reaction in which the products have less Energy that the reactants, so it is energetically favorable. “Spontaneous” but that means that it CAN go, not that it WILL go |
|
|
Term
| How is ATP used to make reactions occur? |
|
Definition
| -ATP is hydrolyzed to ADP + Pi in conjunction with another reaction that uses the energy from ATP to overcome it’s Activation Energy so that a reaction can occur. Instead of energy being lost to heat the energy is harnessed*check this* So this would be a coupled reaction.-ATP is used to create a high energy intermediate product. |
|
|
Term
| What is the enzyme that is used to turn glutamic acid to Glutamine? |
|
Definition
|
|
Term
| What effect does an Enzyme have on activation energy? |
|
Definition
| -Basically it lowers the activation energy (although really doesn’t it provide an energy boost?) in the presence of an enzyme reactants are much more likely to convert to the product. |
|
|
Term
| What is this process called where and enzyme helps a reaction occur? |
|
Definition
|
|
Term
| Where does catalysis occur? |
|
Definition
| -at an enzyme’s active site, the substrate binds to the active site. |
|
|
Term
| Can an enzyme bind with multiple substrates? |
|
Definition
| -No. Enzyme active sites are very specific. Specific R groups near the active site interact with the substrate. R groups form H bonds with specific parts of the molecule and ONLY that molecule (substrate) |
|
|
Term
| What is an enzyme pathway? |
|
Definition
| -A series of enzymes lined up so that the product of the first enzyme is the substrate of the second, etc. |
|
|
Term
| What is often a function of enzyme pathways? |
|
Definition
| -They are often used as a regulation mechanism, ex. final product can inhibit the 1st enzyme. This is what occurs in cell respiration |
|
|
Term
| What is feedback inhibition? |
|
Definition
|
|
Term
| What are the two different kinds of feedback inhibition? |
|
Definition
| -Competitive inhibition: inhibitor binds at the active site, thereby preventing the substrate from binding there----Non-competitive inhibition aka allosteric inhibition: another molecule binds at the allosteric site that is not the active site so that the enzyme changes shape and can no longer bind in the normal way. |
|
|
Term
| What are optimum enzyme conditons? |
|
Definition
| -They vary depending on the kind of organism the enzyme is in, ex, humans most work well at 98 degrees.--Factors that can effect enzyme performance: pH, temp, salt concentration.--Ex. there are enzymes that both cut up proteins, however, the ones that are in the stomach work at a pH of 2.5 but the ones in the intestine work at a pH of 7. |
|
|
Term
| How do larger molecules cross the membrane? |
|
Definition
| -with special transport proteins |
|
|
Term
| What is facilitated Diffusion or Passive Transport? |
|
Definition
| Name:-called passive transport because it doesn’t require an outside source of energy. Driven by a diffusion gradient Function:-a specific protein acts as a carrier or channel to facilitate movement. A solute binds to a protein on one side the protein then closes and opens on the other side. However the proteins have a maximum capacity or threshold for letting proteins in and out. |
|
|
Term
| In which direction can facilitated diffusion transport molecules across the membrane? |
|
Definition
| -only in the direction favored by the concentration gradient (aka chemical gradient orelectrochemical gradient) so from high concentration to low concentration. |
|
|
Term
| What is a typical concentration of Na+ ions in and out of the cell? |
|
Definition
| -In cell 1x, out of cell, 10x |
|
|
Term
| What is a typical concentration of K+ ions in and out of the cell? |
|
Definition
| -In cell 10x, out of cell, 1x |
|
|
Term
| What other ion concentration is carefully monitored? |
|
Definition
|
|
Term
| What are large macromolecules usually charged, what side of the membrane are they on and what is their typical pH? |
|
Definition
| -usually negatively charged, these “fixed anions” are all on the inside of the cell and they are usually at pH 7 |
|
|
Term
| What is active transport, where is it and how does it work? |
|
Definition
| Active transport transports molecules across the membrane and works against the concentration gradient. It also requires an input of energy. It is also embedded in the membrane. |
|
|
Term
| What are the three kinds of transport carriers? |
|
Definition
| 1.Uniport: brings one molecule across, 2: Symport: brings two substances across in the same direction, 3: Antiport: brings two substances across in opposite directions. |
|
|
Term
| How many kcals are released when ATP is hydrolyzed to ADP? |
|
Definition
|
|
Term
| What are the steps in the Na+/K+ ATPase pump? |
|
Definition
| 1: 3 Na+ bind to the ATPase in the cytosol, 2: 2 K+ bind from the exterior of the cell 3: ATP is hydrolyzed to ADP +Pi, 4: The Na+ is now on the outside of the cell and the K+ enters the cell |
|
|
Term
| Where is the Na+/K+ ATPase pump located? |
|
Definition
| -in the membrane of ALL eukaryotic cells |
|
|
Term
| What is the ratio of K in to Na out? |
|
Definition
| 2 K in for every 3 Na out |
|
|
Term
| What drives each step of the reaction? |
|
Definition
|
|
Term
| What does the Na+/K+ ATPase pump maintain in terms of Na and K concentrations? |
|
Definition
| -high K+ concentration in the cell and high Na+ concentration outside of the cell |
|
|
Term
| The Na+/K+ ATPase pump is an example of what kind of transport protein? |
|
Definition
|
|
Term
| How does the Na+ Glucose Symport work? |
|
Definition
| -a carrier protein binds to Na+ and glucose but will only work if BOTH are bound to the protein. Na+ is then shipped out of the epithelial cell to maintain the concentration gradient. Glucose then moves from the epithelial cell through the glucose uniporter through passive transport to the inside of the cell. |
|
|
Term
| Is it possible for something to enter the inside of the cell without going through the epithelial cell? |
|
Definition
|
|
Term
| Is intracellular glucose kept high or low because of the glucose sodium symport? |
|
Definition
|
|
Term
| Is the intracellecular Na+ concentration kept high or low because of the glucose sodium symport? |
|
Definition
|
|
Term
| How many Na+ ions bind to the Na+/Glucose symport for every molecule of glucose? |
|
Definition
|
|
Term
| -What is a channel protein? |
|
Definition
| A protein that usually let ions enter the cell. However, they are regulated and are not permanently open or closed. They are usually controlled because something binds to the protein |
|
|
Term
| What are the 4 kinds of channel proteins? |
|
Definition
| 1:Voltage gated: electrical potential changes--> gate opens 2: Ligand gated (extracellular): ligand binds to channel protein and the channel opens 3: Ligand gated (intra cellcular): same just on the inside of the cell 4: Stress activated: stress changes cause the protein channel to open |
|
|
Term
| How are large quantities (bulk) transported out of the membrane? |
|
Definition
| -Exocytosis. A Phospholipid vesicle formed by the Golgi envelops bulk material for export, then binds to the cell membrane and dumps the contents out of the cell. |
|
|
Term
|
Definition
| -The opposite of exocytosis, i.e. when the cell actively throws out the membrane to wrap around things it wants to bring into the cell |
|
|
Term
| What are the three kinds of endocytosis? |
|
Definition
| 1.Phagocytosis (cell eating): the membrane engulfs food or another cell which fuses with a lysosome to become digested 2. Pinocytosis (cell drinking): the cell engulfs fluid with dissolved solutes 3. Receptor-mediated endocytosis (RME): the membrane doesn’t form a vesicle unless certain ligands bind to receptors which tell the cell “I’ve got one” Doesn’t usually bring the ligand in to the cell but it is possible. |
|
|
Term
| What is the coated/coding pit? |
|
Definition
| An area of the membrane that is coated with clathrin molecules on the inside. It is here that the cell can undergo RME |
|
|
Term
|
Definition
| 1.Ligands bind to receptors 2: Binding code goes out to cell 3: Clathrin molecules fold membrane in and form a vesicle 4: Bound ligand molecules are inside the vesicle which is now called an endosome 5: The binding receptors break off and are moved out of the cell via a vesicle. 6:The endosome fuses with a lysosome or the Golgi. |
|
|
Term
| How does RME related to LDL cholesterol? |
|
Definition
| -LDL cholesterol is low if receptor molecules work well. However, when they stop working well is when someone develops health problems. LDL bind to the coated pit. |
|
|
Term
| What do epithelium cells do? Why are they a good example cell to look at for cell junctions? |
|
Definition
| -they form a tight layer, they are a classic place to find cell junctions because of that. |
|
|
Term
| What is the “basal lamina”? |
|
Definition
| -A special form of extracellular matrix that the cell sits on and that holds the epithelial cells together |
|
|
Term
|
Definition
| -A cell that is packed in with epithelial cells that secretes mucus to protect and lubricate cell layers. |
|
|
Term
| What are the three functions of cell junctions? |
|
Definition
| Sealing; Adhesion; Communication |
|
|
Term
| What is the apical surface? |
|
Definition
| -The side of the epithelial cell with microvilli that faces the lumen |
|
|
Term
| What are the three kinds of cell junctions: |
|
Definition
| Tight junctions, Adherens junctions, Gap junctions |
|
|
Term
|
Definition
| Location: usually just below the apical surface between epithelial cells Structure: quilting/sewn effect, bind membrane of two cells together Function: to bind two cells and prevent leaks from lumen to the tissue/blood. Restricts the movement in the membrane since proteins and phospholipids MUST go through the NOT between them. |
|
|
Term
| Adherens junctions: L/Str/Func? |
|
Definition
| Loc: located just below the apical surface, Str: bundle of actin filaments, Func: belt of actin that goes around cell. Cadherins proteins on the membrane are bound to actin filaments |
|
|
Term
| What are desmosomes? Func/Str/Loc? |
|
Definition
| Desmosomes are a cadherin protein bound to an intermediate fiber. Func: to link one desmosome to another Str: overlap to form junction. Linked to the plaque on the inside of the cell made up of intracellular anchor proteins(aka intermediate fibers, i.e. keratin in a skin cell) Loc: various places in the cell, also in the membrane between cells |
|
|
Term
| What are hemidesmosomes? Func/Str/Loc? |
|
Definition
| -half of a desmosome-made up of integrin molecules-links to the basal lamina with an integrin molecule |
|
|
Term
| What is a gap junction? Loc/Str/Func? |
|
Definition
| -are used to communicate between cells 2 connexons line up to form a junction in the membrane Allows on very small things to go through: ions, water and small signaling molecules. -allows for multiple cells to rapidly communicate signal changes, for example they are commonly found in cardiac muscle. |
|
|
Term
| *What is cellular respiration? |
|
Definition
| the process by which a cell makes ATP |
|
|
Term
| What are the two ways a cell can oxidize glucose? |
|
Definition
| Burn the glucose and all of the free energy is released as heat, or through stepwise oxidation where the energy from the glucose can be harnessed and used |
|
|
Term
| What are the two basic ways to make ATP? |
|
Definition
| Substrate level phosphorylation and chemiosmotic synthesis |
|
|
Term
| What is substrate level phosphorylation? |
|
Definition
| When ATP is made by an enzyme reaction using a high energy phosphate bond of the substrate PEP-Pi to drive the formation of ATP. i.e. make ATP by a substrate reaction |
|
|
Term
| What is chemiosmotic synthesis of ATP? |
|
Definition
| Energy comes from an H+ proton gradient concentration that is harnessed by ATP synthase, an enzyme that produces ATP. H+ protons flow into the enzyme rotor, causing the enzyme to rotate and as it does the catalytic head of ATP Synthase phosphorylizes ADP into ATP. |
|
|
Term
| What are some of the main differences between chemiosmotic synthesis of ATP and substrate level phosphorylation of ATP? |
|
Definition
| The energy source: substrate level phosphorylation uses the energy in a high energy bond, whereas chemiosmotic synthesis using the energy from a concentration gradient of protons. Also chemiosmotic synthesis makes much more ATP than substrate level phosphorylation |
|
|
Term
| Where are the three places ATP is made in the cell? |
|
Definition
| By glycolysis in the cell, where glucose is turned into pyruvate; when pyruvate is oxidized into Acetyl CoA just inside the mitochondrial membrane; and during the Krebs cycle whe Acetyl CoA--> H20 and CO2. |
|
|
Term
| What does glycolysis mean? |
|
Definition
| “the splitting of sugars” |
|
|
Term
| Does glycolysis occur in all cells? |
|
Definition
|
|
Term
| Where does glycolysis occur? |
|
Definition
|
|
Term
| Does glycolysis require oxygen? |
|
Definition
|
|
Term
| Is glycolysis a relatively new or old pathway? |
|
Definition
| Very primitive, has been around for a very long time |
|
|
Term
| **What happens during glycolysis? |
|
Definition
| The cell starts with one glucose (6c) molecule and needs 2 ATP. The glucose is broken down into 2 Fructose (3C) 2 NAD+ are reduced to NADH |
|
|
Term
| What are the Ins and outs of glycolysis? |
|
Definition
| IN: glucose, 2 ATP, 2 NAD+ OUT: 2 ATP, 2 NADH (which will yield 4 ATP during chemiosmotic synthesis in the presence of oxygen), 2 pyruvate. |
|
|
Term
| Are the ATP generated in Glycolysis from substrate level phosphorylation or chemiosmotic synthesis? |
|
Definition
| They are from substrate level phosphorylation (although the NADH created from this process will eventually be turned into ATP also but that occurs during oxidative respiration through chemiosmotic synthesis) |
|
|
Term
| What happens to pyruvate if there is oxygen available in the cell? |
|
Definition
| It gets oxidized into Acetyl CoA in the mitochondria just inside the inner membrane |
|
|
Term
| What happens to pyruvate if there is NOT oxygen available in the cell? |
|
Definition
| It goes through a process called fermentation |
|
|
Term
|
Definition
| A process where an organic molecule is used to accept electrons from NADH so that NAD+ can be regenerated for glycolysis in the absence of oxygen and keep producing ATP |
|
|
Term
| What is an example of when fermentation occurs instead of phosphorylated oxidation? |
|
Definition
| Ex. when someone does a 100 yd dash. There is not enough oxygen available to satisfy the oxidated pathways so instead pyruvate is broken down through fermentation. The reason that we need to breathe heavily after such an exercise is that we have accumulated an oxygen debt so we start breathing heavily to replace that debt. |
|
|
Term
| What occurs during fermentation? |
|
Definition
| Pyruvate is used to accept electrons from NADH so that NAD+ can be recycled. The enzyme that does this converts pyruvate into lactate (or lactic acid) which is fuel that can be oxidized and converted into glycogen |
|
|
Term
| True/False: being in good shape means producing a lot of lactic acid and clearing it quickly? |
|
Definition
|
|
Term
| True/False: lactic acid is to blame for sore muscles? |
|
Definition
| False, this results from other stresses |
|
|
Term
| What are the conditions under which fermentation occurs in yeast? |
|
Definition
| Only under low oxygen conditions |
|
|
Term
| How many ATP are produced from glycolysis? |
|
Definition
| 2, net energy yield of 2% |
|
|
Term
| How many mitochondria are in an average cell? |
|
Definition
| From a few to a few thousand |
|
|
Term
| What enzyme is used to oxidize pyruvate? |
|
Definition
| Pyruvate dehydrogenase (a 3 enzyme complex) |
|
|
Term
| What happens when pyruvate is oxidized? |
|
Definition
| Pyruvate is decarboxylated into Acetyl CoA by using NAD+ |
|
|
Term
| What are the ins and outs of the oxidation of pyruvate? |
|
Definition
| IN: pyruvate, NAD+, CoA OUT: NADH, Acetyl CoA, CO2 |
|
|
Term
| When does the oxidation of pyruvate occur? |
|
Definition
| Between the krebs cycle and glycolysis |
|
|
Term
| What happens in the citric acid cycle? |
|
Definition
| Acetyl CoA is broken down through a series of steps and used to produce electron carrying cofactors (NADH, FADH and GTP) which will all be used to produce ATP in the electron transport cycle. The carbon in Acetyl CoA is converted into CO2. |
|
|
Term
| Why is this process called the citric acid cycle? |
|
Definition
| Because a convention was adopted whereby cycles like these are named for the product of the first step which in this case is citrate or citric acid. |
|
|
Term
| What are the ins and outs of the citric acid cycle? |
|
Definition
| IN: Acetyl CoA, 3 NAD+, 1 FAD+, 1 GDP OUT: 3 NADH, 1 FADH, 1 GTP, 2 CO2 **just remember that this happens twice for every glucose molecule. |
|
|
Term
| What is the electron transport system? |
|
Definition
| A series of proteins embedded in the inner membrane of the mitochondria that use the electrons from NADH and FADH to produce water which drives the production of ATP |
|
|
Term
| What do we call the series of protons in the electron transport system? |
|
Definition
| The electron transport system |
|
|
Term
| What occurs during the electron transport system? |
|
Definition
| 1. Enzymes attract e- from NADH, break off e- and regenerate NAD+. 2. As the e- are passed along the enzymes some energy is used to pump H+ protons into the intermembrane space from the mitochondrial membrane (i.e. to produce a gradient) 3. The energy from the electrons is used to produce water, which drives the entire reaction. Protons diffuse down their concentration gradient, drive ATP synthesis. |
|
|
Term
| What occurs during the chemiosmotic synthesis of ATP? |
|
Definition
| Proton pumps that are a part of the electron transport system create a gradient, 2: electron gradient drives ATP synthase, 3: ATP is produced and H+ is used to create water |
|
|
Term
| What drives the entire chemiosmotic production of ATP in the mitochondria? |
|
Definition
| O2’s demand for electrons |
|
|
Term
| What does a phosphatase enzyme do? |
|
Definition
| It removes phosphate from a molecule |
|
|
Term
| What does a kinase enzyme do? |
|
Definition
| It adds a phosphate to a molecule |
|
|
Term
| What is the efficiency of oxidated phosphorylation/respiration? |
|
Definition
| About 38 percent, so much higher than the 2% of glycolysis (about 20 times more efficient) |
|
|
Term
| How is cellular respiration regulated? |
|
Definition
| By feedback inhibition from either excess ATP or excess NADH |
|
|
Term
| What did the Racker experiment show? |
|
Definition
| The link between ATP and H+ gradient. Inverted the cell membrane, added ATP and protons were pumped out of the cell |
|
|
Term
| What is the P Mitchell hypothesis? |
|
Definition
| That ATP synthase needs a gradient to work. If H+ just flows directly into the cell (what they did) then the ATP synthase will not work |
|
|
Term
| How do fats contribute to cell respiration? |
|
Definition
|
|
Term
| How do proteins contribute to cell respiration? |
|
Definition
| They produce Acetyl CoA, pyruvate and create NH3 as a waste product |
|
|
Term
| Is cell respiration the only metabolic pathway? |
|
Definition
| NO, but it is the main pathway, so it is connected to many of the other metabolic pathways. |
|
|
Term
| How do scientists think that mitochondria developed a double membrane? |
|
Definition
| That they evolved from a primitive eukaryotic cell that engulfed a bacteria but did not break it down. |
|
|
Term
| What is the name for organisms that do photosynthesis? |
|
Definition
| Autotrophs “self-feeders” |
|
|
Term
| What is the name for organisms that don’t do photosynthesis? |
|
Definition
| Heterotrophs “outer eaters”, eat molecules from outside sources |
|
|
Term
| What is the structure of choloroplasts? |
|
Definition
| They have a double membrane, although the space in between them isn’t important, the space inside is the stroma, the main structure inside the chloroplasts are called thylakoid discs and stacks of them are granum, the links between these are lamellae |
|
|
Term
| What do we call the space inside of thylakoid discs? |
|
Definition
| Thylakoid space, it’s hollow |
|
|
Term
| What kind of energy is light? |
|
Definition
|
|
Term
| What is the wavelength spectrum of visible light? |
|
Definition
| 700nm (red) to 450 nm (violent) |
|
|
Term
|
Definition
| Because the absorb all of the visible light frequencies except green |
|
|
Term
| What is the major pigment molecule in chloroplasts? |
|
Definition
Chlorophyll molecules (α and β) |
|
|
Term
| Where are chlorophyll molecules located? |
|
Definition
| They are embedded in a protein complex in the thylakoid membrane |
|
|
Term
| What is the structure of chlorophyll molecules? |
|
Definition
| A porphyrin ring with a hydrophobic tail (like a lipid) |
|
|
Term
| Why do leaves change colors in the fall? |
|
Definition
| Because plants turn off the synthesis of chlorophyll so other colors show that are no longer absorbed by the chlorophyll |
|
|
Term
| What is another name for a photosystem? |
|
Definition
|
|
Term
| What occurs in a photosystem? |
|
Definition
| 1.a photon is absorbed, 2: the energy from the photon is absorbed and passed along to the reaction center, then the electron is boosted and passed on to an e- acceptor. |
|
|
Term
| What occurs in the light reactions of photosynthesis? |
|
Definition
| 1. In Photosystem II An enzyme splits water to get an electron, and the energy from an absorbed photon boosts this electron. O2 is created as a waste product. 2. A proton pump uses some of this energy to create an H+ gradient so that when the gradient is high enough, ATP is produced via ATP synthase. 3. In Photosystem I the electron is boosted again and passed over to produce NADPH which is used as an energy source in the dark reactions. |
|
|
Term
| What are the ins and outs of the light reactions? |
|
Definition
| In: light (photon),H2O, PS I and PS II OUT: NADPH, ATP and O2 |
|
|
Term
| What is produced in the light reactions of photosynthesis? |
|
Definition
| ATP, NADPH and Oxygen are produced. |
|
|
Term
| What is the maximum absorption of photosystem II? |
|
Definition
|
|
Term
| Why is photosystem II the only one that can split water? |
|
Definition
| Because it absorbs the correct energy of light to carry out this reaction. |
|
|
Term
| What is the advantage of the dual photosystem? |
|
Definition
| Get both ATP and reducing power |
|
|
Term
| What is cyclic photophosphorylation? |
|
Definition
| Only using PS I, primitive pathway, used to supplement levels of ATP when needed through the proton gradient |
|
|
Term
| Are these the only photosynthesis mechanisms (PS I and II)? |
|
Definition
| No, there are other photosynthesis mechanisms, some use H2S as a source of electrons so the byproduct is S2 gas instead of oxygen. |
|
|
Term
| What is the major product of the dark reactions? |
|
Definition
|
|
Term
| What occurs during the dark reactions? |
|
Definition
| A series of reactions called the Calvin cycle |
|
|
Term
| What is the first step of the Calvin cycle? |
|
Definition
|
|
Term
| What occurs during Carbon fixation? |
|
Definition
| Carbon from 3 CO2 molecules from the atmosphere is incorporated into 3 organic 5C molecules (Total C is 18) |
|
|
Term
| What occurs after carbon fixation in the Calvin cycle? |
|
Definition
| The product formed when carbon is fixated is very unstable so it immediately splits into two 3C molecules. These 3C molecules keep getting modified until one of them is released as G3P (a 3 Carbon molecule) however the cycle has to run 3 times to produce this, which combines with another G3P to make Glucose, a 6C molecule. |
|
|
Term
| Why does the calvin cycle have to run 3 times to produce G3P and 6 times to produce glucose? |
|
Definition
| Because carbon only fixates once each cycle. |
|
|
Term
| What is the name of the enzyme that fixates carbon from CO2? |
|
Definition
| Ribulose biphosphate carboxylase |
|
|
Term
| What is a competitive inhibitor of CO2 in the enzyme ribulose biphosphate carboxylase? |
|
Definition
|
|
Term
| Why is O2 acting as a competitive inhibitor a problem for some plants? |
|
Definition
| Because O2 binds instead of CO2 which leads to photorespiration and a carbon LOSS instead of a carbon GAIN. i.e. instead of removing carbon from the atmosphere and converting it to oxygen they contribute more carbon to the atmosphere. |
|
|
Term
| What goes in and out of the dark reactions? |
|
Definition
| In: ATP, NADPH, CO2 Out: NADP+ and ADP and 6C sugars |
|
|
Term
| What is the connection between the light and dark reactions? |
|
Definition
| The light reactions produce ATP and NADPH that are used to run the dark reactions. The dark reactions produce NADP+ and ADP which are recycled in the light reactions. |
|
|
Term
| What is the connection between photosynthesis and respiration? |
|
Definition
| photosynthesis produces glucose and O2 that are used in respiration. Respiration produces H20 and CO2 that are used in photosynthesis? |
|
|
Term
| What kinds of organisms do photosynthesis? |
|
Definition
|
|
Term
| What kinds of organisms run respiration? |
|
Definition
|
|
Term
| What happens in hot weather to plants? |
|
Definition
| Leaves lose water because of evaporation through openings called stomata, which open and close depending on how hydrated the leaves are. When the close they trap O2 inside and CO2 doesn’t enter from the outside of the cells |
|
|
Term
| what is an epithelium cell? |
|
Definition
| tissues that line a void in the body – tend to be held tightly together by cell junctions and rest upon a basal lamina (basement membrane) |
|
|
Term
|
Definition
| a membrane bound organelle in plant and fungal cells. it has an acidic pH usually gets rid of unwanted materials from the cell including waste products, supports plant structures. Maintains turgor pressure |
|
|
Term
| What are the three stages of glycolysis? |
|
Definition
| Energy investment of 2 ATP (will be recouped later), division of 6C sugar into 2 3C sugars, energy generation (4 ATP, 2 NADH) and generation of 2 pyruvate |
|
|
Term
| Do bacteria have mitochondria? |
|
Definition
| No, never because they developed from bacteria so they essentially do the same thing |
|
|
Term
| what kind of inhibition is feedback inhibition? |
|
Definition
| non competitive aka allosteric inhibition |
|
|
Term
| what is the difference between a ligand and a cofactor? |
|
Definition
a ligand is bound by a receptor, or a surface protein
a cofactor is a substance required by the enzyme to work, ex. NAD+ |
|
|
Term
| what do antibodies bind to? |
|
Definition
|
|
Term
| what kind of proton pump pumps H+ protons into the lysosome? |
|
Definition
| Active transport that uses ATP as an energy source |
|
|
Term
| where do we find circular DNA in mitochondria and chloroplasts? |
|
Definition
|
|
Term
| what is the structure located at the beginning of a flagella or cilia? |
|
Definition
|
|
Term
| what happens to digested material in the lysosome? |
|
Definition
| it is broken down into monomer units that the cell can use |
|
|
Term
| what is an example of when hydrolysis occurs in cell respiration? |
|
Definition
| when the 6C glucose molecule is split into two 3C fructoses during glycolysis |
|
|
Term
| what is allosteric inhibition? |
|
Definition
| non-competitive inhibition |
|
|
Term
| what molecule forms the head of a lipid or phospholipid? |
|
Definition
|
|
Term
| when does mitochondria make ATP? |
|
Definition
| all the time since we are constantly respiring and the main thing needed for ATP synthesis is oxygen |
|
|
Term
| how does the sequence of atoms in the backbone of a protein compare to the sequence that would be seen in another protein? |
|
Definition
| they are the same since the R groups face in. The backbone of peptide bonds is the same, the difference is the R groups only but basically the chain is just a series of peptide bonds |
|
|
Term
| do shorter fatty acid tails give more or less fluidity in membranes than fatty acids with long tails> |
|
Definition
|
|
Term
| what does photolysis mean? |
|
Definition
|
|
