Term
|
Definition
| can be either alpha or beta in the cyclic form depending on the location of the OH group. If it's up, it's beta and if it's down, it's alpha |
|
|
Term
| Enantiomeric form of carbs |
|
Definition
is classified as either D or L based on the last chiral atom in the carbohydrate linear form (should be the next to last group in the chain)
If the OH group is on the right, it's D
If the OH group is on the left, it's L |
|
|
Term
|
Definition
| carbs that differ at one carbon cebter other than the second to last carbon and the anomeric carbon |
|
|
Term
| Anomeric carbon of a carbohydrate |
|
Definition
| in the cyclic form, this is the carbon that is attached to the ring oxygen and an OH group. In the linear form, this is the carbon that is the carbonyl carbon |
|
|
Term
|
Definition
drill this using notecard
hexose structure, all OH groups are down except for on carbono 3 |
|
|
Term
|
Definition
drill this using notecard
pentose structure, has to CH2OH groups on carbons on either side of the center O |
|
|
Term
| How to convert between Fischer and Haworth projection |
|
Definition
| in the linear form, if the groups are on the left, they are up in the cyclic form and if the groups are on the right in the linear form, they are down in the cyclic form |
|
|
Term
| Significance of a reducing sugar |
|
Definition
| the anomeric carbon of a sugar (the one that forms the carbonyl) has the power to reduce substances such as Benedict's reagent. These can be distinguished from a regular sugar because if it reacts with the reagent, you know it's already been oxidized. |
|
|
Term
| How derivatization effects reducibility |
|
Definition
| any reaction that attaches to the anomeric carbon effects the reducibility because the sugar will no longer be able to switch to the linear form and the linear form is the only form that carries the reactive carbonyl group. |
|
|
Term
| How to number carbons on a carbohydrate |
|
Definition
for an aldose, numbering starts with the carbonyl carbon in the linear form which will be the anomeric carbon in the cyclic form
for a ketose (such as fructose), the carbonyl carbon is C2 instead of C1 in the linear form so the carbon group that projects from the ring is the start |
|
|
Term
| Classifying alpha linkages vs beta linkages |
|
Definition
| based off the textbook, beta linkages will have kind of the figure 8 bond while alpha linkages will have bonds that are like |_o_|, basically L's |
|
|
Term
| Linkages present in starch |
|
Definition
Remember starch can come in 2 forms, amylose and amylopectin
amylose has alpha (1-4) linkages while amylopectin also has alpha (1-4) linkages but for every 24-30 residues it has an alpha (1-6) linkage to a glucose molecule which makes it branching |
|
|
Term
| Linkages present in Glycogen |
|
Definition
| same linkages as amylopectin (alpha 1-4) but has alpha (1-6) linkages every 12 residues. This forms shorter chains but it is very highly branched |
|
|
Term
| Linkages present in cellulose |
|
Definition
| has beta (1-4) linkages of glucose |
|
|
Term
|
Definition
| the linear form of starch that has alpha (1-4) linkages of glucose. has a kink in its structure |
|
|
Term
|
Definition
| the branched form of starch that for every 24 to 30 residues, it has an alpha (1-6) linkage to glucose. Forms a larger molecule than amylose because of the branching though it has shorter chains |
|
|
Term
| How to recognize homopolymer vs heteropolymer of sugars |
|
Definition
| a homopolymer contains a sequence of a single unit while heteropolymers contain a mix of more than one unit |
|
|
Term
|
Definition
| Harbors a community for microbes but the gel like consistency of a biofilm makes the bacterial cells hard to remove |
|
|
Term
| 2 main types of glycoproteins |
|
Definition
|
|
Term
|
Definition
| glycoproteins where the sugar is attached to the amino group of Asn side chain |
|
|
Term
|
Definition
| glycoproteins where the sugar is attachd to the oxygen of either Ser or Thr's side chain |
|
|
Term
| Similarities between N-glycosylation and O-glycosylation |
|
Definition
| both build glycoproteins, gives variety |
|
|
Term
| Differences between N-glycosylation and O-glycosylation |
|
Definition
O-linked oligosaccharides do not undergo processing so they tend to be larger.
N-linked oligosaccharides are processed by glycosidases which initially trims the oligosaccharide and then new residues are added by glycosyltransferases.
O-linked occurs in the Golgi, N-linked occurs in the RER and ER lumen |
|
|
Term
|
Definition
the process where a glycoprotein is formed by a chain of 14 carbohydrates attaching itself to the amino group of Asn's side chain
This process begins as soon as the protein comes off the ribosome in the RER and the sugar is added while the protein is entering the ER lumen
N-linked oligosaccharides are processed by glycosidases which initially trims the oligosaccharide and then new residues are added by glycosyltransferases. |
|
|
Term
|
Definition
| a glycoprotein is built by residues attaching one a time inside the Golgi |
|
|
Term
|
Definition
| The added sugar groups gives variety, used as an addressing system, helps guide molecular chaperones, is protective, and is highly hydrophilic so it occupies a large volume above protein's surface |
|
|
Term
|
Definition
they are a special type of glycoprotein, but consists of only a small amount of protein
are typically O-linked
A sulfate group can be added post-synthesis
Protein portion is membrane bound either by transmembrane or lipid linked |
|
|
Term
| Where are the sugar chains of proteoglycans typically located? |
|
Definition
| usually on the extracellular side |
|
|
Term
| What is the general purpose of proteoglycans? |
|
Definition
| is important in connective tissue and acts like a sponge to absorb shock |
|
|
Term
| What is an example of a proteoglycan? |
|
Definition
|
|
Term
| Why are anabolic processes compatible with a net increase in entropy? |
|
Definition
| im guessing because they occur with metabolic processes so they contribute to a decrease in entropy at the expense of an increase in environmental energy? ugh i don't know |
|
|
Term
| Two branches of metabolism |
|
Definition
|
|
Term
|
Definition
| the breakdown of larger molecules to release free energy |
|
|
Term
|
Definition
| uses the energy released by catabolism to build molecules |
|
|
Term
| General process of extracellular digestion |
|
Definition
| Digestion begins in the mouth with the help of amylases, then in the stomach proteins are digested by proteases, lipases that are secreted into the intestine digest fatty acids and the smaller compounds get absorbed by the intestinal wall |
|
|
Term
| General processing of fatty acids |
|
Definition
inside the cell, fatty acids reform triglycerides and these triglycerides along with cholesterol esters form chylomicrons (lipoproteins)
and these chylomicrons are released into the bloodstream |
|
|
Term
| General processing of amino acids and sugars |
|
Definition
| are water soluble so they leave intestine and enter portal vein leading to liver |
|
|
Term
|
Definition
| Fatty acids are stored in the form of triglycerols in adipocytes |
|
|
Term
|
Definition
| glucose is stored as glycogen in the liver and muscle |
|
|
Term
| What happens to excess glucose during overeating? |
|
Definition
| During overeating, glycogen stores eventually fill up and the glucose is converted into fatty acids and stored |
|
|
Term
| What happens to excess amino acids during overeating? |
|
Definition
| Amino acids doesn't really have a real storage facility but it will get converted to glucose and stored as glycogen and in the case of excessive overeating will be converted to fatty acids and stored as fat |
|
|
Term
| Phosphorolysis of glycogen |
|
Definition
the degradation of glycogen.
In this process (done in the liver), the enzyme glycogen phosphorylase removes glucose residues one at a time from the ends by adding a phosphate group to glucose which breaks the glycosidic bond between 2 glucose residues.
Before this released glucose gets sent into the bloodstream, that phosphate group has to be removed |
|
|
Term
| The release of fatty acids by lipases |
|
Definition
| When glucose is low, lipase releases fatty acids from triacylglycerols and the fatty acids are catabolised |
|
|
Term
| Why are fats the last energy reserve to be tapped under normal conditions? |
|
Definition
the body does not have a budget for burning fatty acids and will only do so when carbs and amino acids aren't meeting the body's energy needs
has a higher potential source than carbs or amino acids and is the most valuable reserve |
|
|
Term
| When is cellular protein broken down? |
|
Definition
| only during starvation because breaking down protein requires more processing |
|
|
Term
| Protein degradation by lysosomes |
|
Definition
| a protein is enclosed in a vesicle and fuses with a lysosome and is broken down |
|
|
Term
| Protein degradation by proteasomes |
|
Definition
| before degradation, a protein gets tagged with ubiquitin (attached to Lys side chain) which notifies the cell that it needs to go to the proteasome. As it enters the proteasome, the polypeptide is unfolded (which requires energy) and peptide bonds are clipped. The individual peptides diffuse away |
|
|
Term
|
Definition
| a barrel-shaped multiprotein complex that degrades protein in the cytoplasm |
|
|
Term
| What is a metabolic pathway? |
|
Definition
A metabolic pathway is a series of chemical reactions needed to break down a monomer or build up one.
It has multiple steps and multiple enzymes used for the chemical reactions |
|
|
Term
| Benefits of multi-step pathways in a metabolic pathway? |
|
Definition
| It allows you to convert a large energy source into multiple smaller sources of energy. This lessens the chance for energy to be wasted and smaller packets of energy means the cell doesn't spend what they don't need (why break up a $50 bill when you only need $1) |
|
|
Term
| 3 key players in glycolysis |
|
Definition
| Gly-3-P,, pyruvate, acetyl-CoA |
|
|
Term
| In general, the catabolism of amino acids, monosaccharides, and fatty acids is a process of oxidizing carbon atoms, and the synthesis of these compounds involves carbon reduction |
|
Definition
|
|
Term
| Different types of electron carriers and how many electrons they carry (COME BACK TO THIS QUESTION) |
|
Definition
NAD+, NADP+, ubiquinone
NAD+ can carry 2 electrons
Ubiquinone can carry up to 2 electrons |
|
|
Term
| Difference between water soluble electron carriers and lipid soluble electron carriers |
|
Definition
| Water soluble electron carriers can travel throughout the cell, shuttling electrons from reduced compounds to oxidized compounds |
|
|
Term
| Why are vitamins important? |
|
Definition
| vitamins are compounds that humans need but can't make and human metabolism depends on them |
|
|
Term
| Standard conditions for chemical systems |
|
Definition
25 C, 298 K
1 atm pressure
1 M concentrations of reactants |
|
|
Term
| Standard conditions for biochemical systems |
|
Definition
25 C, 298 K
1 atm pressure
1 M concentrations of reactants
ph of 7
water concentration of 55.5 M |
|
|
Term
| Difference between the actual and standard free energy change of a reaction |
|
Definition
| The standard free energy change is a constant value for a certain reaction at standard conditions. The actual is what the free energy change is in different conditions |
|
|
Term
|
Definition
| The process where water breaks a high energy phosphate bond in ATP |
|
|
Term
| Why is there a large favorable change in free energy when ATP is hydrolyzed? |
|
Definition
| the products of hydrolysis are more stable than reactants (negative charges separated) and the products have higher resonance stabilization |
|
|
Term
| Hydrolysis of thioester bonds |
|
Definition
| the thioester bond between the acetyl group and CoA is a high energy bond because that S atom makes it have less resonance stability |
|
|
Term
| What does a small deltaG mean in terms of quilibrium? |
|
Definition
| means there's a small fluctuation in reactant and product concentrations and there's not a strong drive to proceed in a particular direction since they're already near equilibrium |
|
|
Term
| What does a large deltaG mean in terms of quilibrium? |
|
Definition
there's a stronger drive to proceed forward since they have a longer way to reach equilibrium
This is where regulation occurs. Enzymes tend to work more slowly in this condition because they are often saturated with substrate and can't go any faster so they can't reach equilibrium |
|
|
Term
| Different ways to regulate metabolic enzymes |
|
Definition
| Increase the concentration of the enzyme, or increase/decrease the activity of the enzyme by using allosteric effectors |
|
|
Term
| Net equation of glycolysis |
|
Definition
| glucose + 2 NAD+ + 2ADP + 2P -> 2 pyruvate + 2NADH + 2ATP |
|
|
Term
| 4 glucose metabolism pathways |
|
Definition
glycolysis - breaks down glucose, catabolic
gluconeogensis - makes glucose, anabolic
glycogen synthesis and degradation - anabolic and catabolic
pentose pathway - generate pentoses, anabolic |
|
|
Term
| Two general purposes of catabolic pathways |
|
Definition
convert energy in starting molecule to more usable form
create intermediates to be used in other pathways |
|
|
Term
| Benefits of a multi-step pathway |
|
Definition
| Multiple steps means greater energy recovery |
|
|
Term
| Two main divisions of glycolysis pathway |
|
Definition
phase 1: energy investment phase
phase 2: energy pay off phase |
|
|
Term
| Three potential control points of glycolysis |
|
Definition
Step 1: phosphate group added to glucose
Step 3: fructose-6-phosphate gets converted to fructose-1,6-bisphosphate
Step 10: phosphoenolpyruvate converted to pyruvate |
|
|
Term
| Enzymes for 3 control points of glycolysis |
|
Definition
Step 1: hexokinase
Step 3: PFK
Step 10: enolase |
|
|
Term
| Real control point of glycolysis |
|
Definition
| Step 3, this is because it's the slowest reaction and is thus the rate determining step |
|
|
Term
|
Definition
For one turn:
1. phosphate group added to glucose to make glucose-6-phosphate
2. glucose-6-phosphate converted to fructose-6-phosphate
3. fructose-6-phoshpate gets phosphate added on to make fructose-1,6-bisphosphate
4. fructose-1,6-bisphosphate gets converted to DHAP and Gly-3-P
5. DHAP from previous step gets converted to Gly-3-P
At this point: products get doubled
6.Gly-3-P is converted to 1,3-bisphosphoglycerate
7. 1,3-bisphosphoglycerate is converted to 3-phosphoglycerate
8. 3-phosphoglycerate is converted to 2-phosphoglycerate
9. 2-phosphoglycerate is converted to phosphoenolpyruvate
10. phosphoenolpyruvate is converted to pryruvate |
|
|
Term
| Which steps of glycolysis cost ATP? |
|
Definition
| 1, 3 (both occur in first phase so 2 ATP are used) |
|
|
Term
| Which steps of glycolysis generate ATP? |
|
Definition
| 7, 10 (both occur in second phase so 4 ATP total are produced) |
|
|
Term
| Where does phosphate group in step 6 come from? |
|
Definition
Remember in step 6, a phosphate group is added to Gly-3-P to profuce 1,3-bisphosphoglycerate
The phosphate comes from inorganic phosphate instead of ATP |
|
|
Term
| PFK regulation in bacteria |
|
Definition
Regulated by + and – allosteric effectors
as [ADP] goes up, need more ATP – turn on pathway
as [PEP] (product from step 9) goes up, too much product – shut down pathway |
|
|
Term
| PFK regulation in mammals |
|
Definition
| When blood glucose is high, insulin is prouced and this stimulates PFK-2 to make Fru-2,6-P2. Fru-2,6-P2 in turn activates PFK-1 so more glucose is sent down the pathway aka broken down |
|
|
Term
| What are 3 potential fates for pyruvate? |
|
Definition
| Can be converted to lactate, oxaloacetate and acetyl-CoA |
|
|
Term
| Why is it a benefit for pyruvate to be converted to lactate when this is a waste product? |
|
Definition
| this process re-oxidizes NADH so it can continue to carry electrons for oxidative processes |
|
|
Term
| Which steps of gluconeogenesis are not the reverse of glycolysis? |
|
Definition
| Can't reverse reaction that converts phosphoenol to pyruvate (step 10), converts fructose-6-phosphate to fructose-1,6-bisphosphate and reaction that converts glucose to glucose-6-phosphate |
|
|
Term
| Enzymes, substrates, and products for glycolysis steps that gluconeogenesis cannot reverse |
|
Definition
Step 1: instead of hexokinase, glucose-6-phosphate is converted to glucose with the help of glucose-6-phosphatase
Step 3: Instead of PFK, fructose-1,6-bisphophate is converted to fructose-6-phosphate with the help of fructose bisphosphatase
Step 10: instead of pyruvate kinase, pyruvate is first converted to oxaloacetate using pyruvate carboxylase, and then oxaloacetate is converted to phosphoenolpyruvate by phosphoenolpyruvate carboxykinase |
|
|
Term
| How is gluconeogenesis regulated? |
|
Definition
Control point is the use of fructose bisphosphatase (reversal of step 3 of glycolysis).
Remember that in step 3, a lot of glucose in the blood leads to the production of insulin and the production of Frc-2,6-P2 which stimulates PFK.
Well Frc-2,6-P2 is an inhibitor of fructose bisphosphatase. Fructose bisphosphatase is needed to convert fructose,1,6-bisphosphate. If there's a lot of glucose in the blood, Frc-2,6-P2 will inhibit fructose bisphosphatase so no more glucose is made |
|
|
Term
| During glycogen synthesis, what is glu-6-p converted to? |
|
Definition
| it's converted to glu-1-P |
|
|
Term
| What is glu-1-P charged with during glycogen synthesis and why? |
|
Definition
it's charged with UDP to form UDP-glucose. This is done because we're adding glucose to a growing chain and this is very unfavorable.
Formation of UDP-glucose is highly favorable because UTP is rapidly hydrolyzed |
|
|
Term
| Substrates for glycogen synthase |
|
Definition
| is both a glucose residue and glycogen because it will add glucose to the glycogen chain |
|
|
Term
| General steps of glycogen phoshphorolysis |
|
Definition
| a glucose residue is removed from glycogen, this residue is converted to Glc-6-P, the phosphate group is removed and glucose is sent to the blood |
|
|
Term
| General purpose of pentose pathway |
|
Definition
| to generate Rib-5-P and NADPH |
|
|
Term
| Why does the pentose phosphate operate in all cells? |
|
Definition
| all cells need to make DNA and RNA |
|
|
Term
| How does the cell recycle components to continue making NADPH during the pentose phosphate pathway? |
|
Definition
| excess carbons are recycled to build glycolytic intermediates Frc-6-P and Gly-3-P |
|
|
Term
| What are the products of recycling during the pentose phosphate pathway |
|
Definition
|
|
Term
| Why is the TCA cycle a central pathway? |
|
Definition
o It is a central pathway because it represents the final stage in the oxidation of metabolic fuels including carbs, amino acids and fatty acids
o It is amphibolic because pyruvate is broken down into CO2 |
|
|
Term
| Net reaction of TCA transition step |
|
Definition
| pyruvate + CoA + NAD+ -> acetyl-CoA + CO2 + NADH |
|
|
Term
| Where does TC take place in the cell |
|
Definition
|
|
Term
| Order of enzyme complex for TCA transition step |
|
Definition
|
|
Term
| Cofactors of TCA transition step and what complex they're associated with |
|
Definition
o TPP (thiamine pyrophosphate): is associated with E1
o Lipoamide: associated with E2 |
|
|
Term
| Which enzyme complex of the transition step of TCA is pyruvate dehydrogenase |
|
Definition
|
|
Term
| Steps to the transition step |
|
Definition
• Step 1: In the E1 complex, pyruvate is decarboxylated. TPP attacks the carbonyl of pyruvate which forces CO2 to leave forming a hydroxyethyl group
• Step 2: The hydroxyethyl group is transferred to E2 where it reacts with lipoamide (Swinging arm). This causes TPP to regenerate and oxidizes the hydrozxethyl group to acetyl
• Step 3: E2 transfers acetyl group to CoA which fully reduces the lipoamide
• Step 4: E3 reoxidizes lipoamide group of E2, Cys-Cys disuflide bond in enzyme is reduced
• Step 5: NAD+ reoxidizes Cys sulfhydryl groups which makes NADH |
|
|
Term
| Benefits of a multi-enzyme complex |
|
Definition
| • can carry out a multistep reaction sequence quickly because the product of one reaction can quickly become the substrate for the next reaction without diffusing away or reacting with something else |
|
|
Term
|
Definition
| acteyl-CoA + GDP + P + 3 NAH+ + Q -> 2 CO2 + CoA + GTP + 3 NADH + QH2 |
|
|
Term
| Which substrate of the TCA cycle is used in the first step and regenerated in the last step? |
|
Definition
|
|
Term
| Which steps of TCA generate NADH, CO2, GTP and QH2 |
|
Definition
• Step 3: Isocitrate dehydrogenase releases the first CO2 by oxidizing isocitrate and forcing it to release CO2 (oxidative decarboxylation). NADH is also released
• Step 4: alpha-Ketoglutarate dehydrogenase releases the second CO2 also by oxidative decarboxylation). NADH is also relased
• Step 5: succinyl-CoA synthetase catalyzes substrate-level phosphorylation which releases GTP
• Step 6: Succinate dehydrogenase generates QH2
• Step 8: Malate dehyrogenase generates NADH |
|
|
Term
| Where do the carbon atoms that are released in TCA come from? |
|
Definition
|
|
Term
| GTP production is an example of what type of phosphorylation |
|
Definition
| of susbtrate-level phosphorylation |
|
|
Term
| What is the Pasteur effect |
|
Definition
• Shift from anaerobic to aerobic conditions decreases glucose consumption. You get more energy out of each molecule so you need to consume less
• 2 ATP in anaerobic conditions vs 32 in aerobic conditions
In the Pasteur effect, reduced cofactors (NADH and QH2) and reoxidized to generate more ATP |
|
|
Term
| How is the TCA regulated? |
|
Definition
Is regulated at 3 steps
Step 1: flux depends largely on substrate concentrations
• if there's a large citrate or succinyl-CoA concentration, it will block Step 1. NADH also blocks Step 1
Step 3: Inhibited by NADH
• activated by Ca and ADP which signifies the need for fuel
Step 4: Inhibited by succinyl-CoA and NADH
• activated by Ca |
|
|
Term
| intermediates feed into and out of pathway for TCA |
|
Definition
|
|
Term
| How do anaplerotic reactions replenish intermediates and why they are essential during the TCA |
|
Definition
You need to replenish intermediates that are siphoned off
An important reaction is pyruvate carboxylate which produces oxaloacetate. The production oxaloacetate leads to the production of citrate, then to isocitrate and so on which results in the concnetrations of the citric acid cycle intermediates increasing |
|
|
Term
| Why is ETC known as oxidative phosphorylation |
|
Definition
| Produces ATP that is driver by a proton gradient |
|
|
Term
| Significance of standard reduction potential |
|
Definition
Tells you the tendency of the oxidized form of a substance to accept electrons
Higher E: more affinity |
|
|
Term
| How to predict electron flow |
|
Definition
| Will always flow from low E to high E |
|
|
Term
| Relationship between Gibbs free energy and reduction potential |
|
Definition
| The higher the E, the more of a change in free energy, the greater the tendency of the electrons to flow |
|
|
Term
| How to calculate change in reduction potential |
|
Definition
| deltaEdegree' = Edeltadegree' (Acceptor) - Edeltadegree'(donor) |
|
|
Term
| distinction between aerobic respiration, anaerobic respiration and fermentation |
|
Definition
| Anaerobic respiration is respiration without oxygen; the process uses a respiratory electron transport chain but does not use oxygen as the electron acceptors. |
|
|
Term
| General structure of mitochondria |
|
Definition
| outer membrane, intercellular space, inner membrane (forms folds of cristae), matrix |
|
|
Term
| • Know how reducing equivalents are moved from the cytosol to the matrix and how the substrates for ATP synthesis are transported into the matrix |
|
Definition
Electrons donate to ETC on matrix side
Transfer electrons to molecule that can be
transported across membrane (malate) then re-oxidize molecule to extract electrons
ATP transporter binds both ATP and ADP. Pumps ATP out and ADP in |
|
|
Term
| order of electron flow in the ETC and why |
|
Definition
Either complex I-> III -> IV
or
complex II -> III -> IV |
|
|
Term
| the components of the ETC and how they function in electron flow |
|
Definition
4 Complexes
I: Electrons from NADH to FMN to Fe-S to Coenzyme Q
also transfers 4 protons from matrix to intermembrane space
II: Electrons from FADH2 to Coenzyme Q
III: Q to Cytochrome c
pumps 4 hydrogens into intermembrane space
IV: Cyt c to O2 |
|
|
Term
|
Definition
FMN Redox center - can accept 2 electrons
Fe-S clusters - 1 electron carrier
cytochromes - 1 electron carrier
Cu2+ (in complex 4) - 1 electron carrier |
|
|
Term
| Cytochromes contain what kind of groups? |
|
Definition
| heme and these are lettered to identify their ring structures |
|
|
Term
|
Definition
First round:
QH2 donates first electron to Fe-S. This electron travels to cytochrome c
QH2 donates second electron to cytochrome b (2 protons are released into intermembrane space)
Q diffuses to binding site and picks up an electron on the way to become semiquinone Q-
Second round
A second QH2 donates proton to Fe-S which travels to cytochrome c
Same QH2 donates second electron to cytochrome b (another 2 protons are pumped into IM space)
Original Q picks up electron from cytochrome B and 2 protons from matrix to become QH2 again
You need more than one QH2 in the pool so they can help each other become reduced |
|
|
Term
| Which components contribute to Q pool |
|
Definition
| Complex III, cytochrome c, cytochrome b, Fe-S |
|
|
Term
| Flow of electrons from QH2 through Complex III to cytochrome c |
|
Definition
|
|
Term
| Stoichiometry of electron flow and O2 consumption |
|
Definition
for every 2 electrons donated to cytochrome c, 1/2O2 is converted to water
or
it takes 4 electrons to fully reduce O2 |
|
|
Term
| general benefits of having a multi-component ETC |
|
Definition
Multiple carriers = multiple H+ pumping stations
Store more of the energy released from electron
transfer – less of the energy is lost |
|
|
Term
|
Definition
o Generates a chemical and electrical gradient
o Retain most of energy released from ETC |
|
|
Term
| Structure of ATP synthase |
|
Definition
Has an F0 complex and an F1 complex
F0: a cylinder composed of 10 c subunits. Attached to F1 and gamma shaft. Also has an a and 2 b components that support the alpha and beta subunits of F1
F1: 2 alpha and 3 beta subunits surrounding a central shaft |
|
|
Term
| Ratio of proton pumping to number of ATP made in ATP synthase |
|
Definition
| 3 protons pumped for every ATP made |
|
|
Term
|
Definition
ATP synthesis depends on gamma shaft
Protons flow through the F0 cylinder which causes the c subunits and thus the gamma shaft to rotate. This rotation causes the shaft to come into contact with a different beta subunit of F1
Beta is loose if it has ADP bound
Beta is tight if it has ATP bound (but no gamma)
Beta is open if it has the gamma shaft bound and this will release ATP |
|
|
Term
| consequence of uncoupling proton pumping from ATP synthesis |
|
Definition
| nothing to drive rotation of gamma and thus no ATP can be made |
|
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Term
| P:O ratio is and how to calculate it |
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Definition
# of phosphorylations of ADP (P) relative to # of O2
reduced (O)
Mitochondrial ATP synthase has 8 c subunits so that's 8 protons per 3 ATP made which is 2.7 protons per 1 ATP
To figure out the P:O for a different number of protons, multiply it by 1/2.7 |
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