Chapter 9 Quiz Prep (Unit 3)

Process of picking up an electron --> just look at what is happening

2- + NAD+ + H+ → NADH 2- + FAD + 2H+ → FADH2 2- + ½O2 + 2H+ → H2O

a suspensoin of cells is ground up and then mixed with a chemical that dissovles fats. which of the following stages of cellular respiration would be most disrupted by this chemical? a. glucolysis b. the citric acid cycle c. oxidative phosphorylation d. fermentation

C! oxidative phosphorylation

When compounds lose electrons, they ______ energy; when compounds gain electrons they _____ energy

When compounds lose electrons, they gain energy; when compounds gain electrons they lose energy

when pyruvate is converted to acetyl CoA,

a multienzyme complex removes CO2, transfers electrons to NAD+, and attaches a coenzyme

fats and proteins can be used as fuel in the cell because they

can be converted to intermediates of glcolysis or the citric acid cycle

Reduction and why is it called this

gain of electrons to another substance Called "reduction" because adding electrons to an atom reduces its positive charge

Predict the number of ATP molecules that could be produced from one glucose molecule if oxygen were not available

2

which of the following statements is an accurate description of chemiosmosis? a. APT production is linked to the proton gradient established by the electron transport chain b. the difference in pH between the intermemebrane space and the cytosol drives the formation of ATP c. the flow of H+ through ATP synthases rotates a rotor and rod, driving the hydrolysis of ADP d the production of water in the mitochondrial matrix by the recution of oxygen leds to a net flow of water out of a mitochondrion

A!!! ATP production is linked to the proton gradient establisehd by the electron transport chain

how is ATP produced in oxidative phosphorylation

ATP synthase catalyses the formation of ATP (adenosine triphosphate) from ADP (adenosine diphosphate) and Pi (INORGANIC phosphate), in processes known as oxidative phosphorylation (driven by oxidations in animal cells and microorganisms)

what happens after fermentation?

After fermentation, NADH is recycled and used to generate more ATP. That's all there is! Now we will go into what will happen after glycolysis if there IS oxygen available. Because oxygen is available, pyruvate will enter the mitochondria to make Acetyl CoA

explain what happens after glycolysis if there is oxygen present AND if there isn't oxygen present

After glycolysis, if there is OXYGEN within the cell, the pyruvate enters the mitochondria in eukaryotes (cytosol for prokaryotes). If there is NO OXYGEN within the cell, pyruvate will go through fermentation

muscle cells in oxygen deprivation gain which of the following from the reduction of pyruvate a. ATP b. ATP and NAD+ c. CO2 and NAD+ d. ATP and CO2

B--> think about fermentation!

which of the following substances produces the most ATP per gram? a. glucose b. glycogen c. fats d. proteins

C! fats, because they are highly reduced compounds

some prokaryotes use anaerobic respiration, a process that a. does not involve an electron transport chain b. produces ATP solely by substrate-level phosphorylation c. uses a substance other than oxygen as the final electron acceptor d. both a and b are correct

C!!!! remember? fermentation doesn't use oxygen! the electron transport chain is still used here

formula for cellular respiration and tell me a little about it

C6H12O6 +6O2 → 6 CO2 + 6H2O + ATP Exergonic; spontaneous; -△G; more of the reactant than product

when are all the carbons from pyruvate offically gone? at what step in cellular respiration?

CITRIC ACID CYCLE BABYYY

Fill in what takes place in certain parts of the cell in Cellular Respiration Cytoplasm _____ _____ Mitochondria: Outer mitochondrial membrane (just define what it is and mention if something is located here) Intermembrane space (lower pH than intermembrane because more H+) _____ Inner mitochondrial membrane _____ _____ Matrix (higher pH than intermembrane because less H+) _____ _____ _____ _____ _____ _____

Cellular Respiration Cytoplasm Glycolysis Fermentation Mitocondria: Outer mitochondrial membrane First phospholipid bilayer Intermembrane space (lower pH than intermembrane because more H+) Protons (H+) are pumped into here from the electron transport chain in the inner mitochondrial membrane Inner mitochondrial membrane Electron transport chain in oxidative phosphorylation with the embedded protein channels ATP synthase Matrix (higher pH than intermembrane because less H+) NADH/FADH2 Water produced ATP Hydrogen ions come out from the ATP synthase from the inner membrane to the matrix Link step Citric acid cycle

define and describe citric acid cycle

Citric acid cycle: FINISHES the breakdown of glucose and fuels the production of ATP in the process, as well as creating NADH/FADH for electron transport chain. Every reaction in the citric acid cycle is mediated by an enzyme NOTE: THE CYCLE DESCRIBED BELOW HAPPENS 2X PER GLUCOSE BECAUSE THERE ARE 2 PYRUVATES The ACETYL GROUP from the pyruvate is attached to OXALOACETATE, forming CITRIC ACID (aka "citrate") The carbons from the acetyl group are oxidized into 2 carbon dioxides → Now, ALL carbons from glucose molecules are officially GONE!!!! Glucose made up of 2 pyruvates and each pyruvate has 3 carbons. For each pyruvate, 1 carbon was lost in the link step and 2 in the citric acid cycle 3 molecules of 2 NAD+ are reduced to NADH 1 molecule of FAD is reduced into FADH2 1 ATP produced The citrate is converted back to oxaloacetate so this cycle can REPEAT

order these parts Inner mitochondrial membrane Matrix Intermembrane space Cytoplasm Outer mitochondrial membrane

Cytoplasm Outer mitochondrial membrane Intermembrane space Inner mitochondrial membrane Matrix

fermentation produces less ATP than cellular respiration because a. NAD+ is regenerated by alcohol or lactate production, whithout the electrons of NADH passing through the electron transport chian b. pyruvate still contains most of the "hilltop" electrons that were present in glucose c. its starting reactant is pyruvate and not glucose d. both a and b are correct

D!

substrate-level phosphorylation a. involves the shiftign of a phosphate group from ATP to a substrate b. takes place only in teh cytool c. accounts for 10% of the ATP formed by fermenetaion d. is the energy source for facultative anaerobes under anaerobic conditions

D! "a" is completely wrong! it binds to ADP not ATP because ATP is being produced!

Explain this: 3 (10 NADH) + 2 (2 FADH2) = 34 ATP

Each NADH molecule will make 3 ATP molecules Each FADH2 molecule will make 2 ATP molecules ^ this is because NADH enters ETC at an earlier protein than FADH2 The 10 NADH and 2 FADH2 is coming from everything produced from glycolysis and the link reaction and is sent to oxidative phosphorylation. There are more NADH because NADH is produced in glycolysis, the link reaction, and the citric acid cycle. FADH2 is only produced in the citric acid cycle. To get the exact numbers, just tallied up all of the inputs and outputs.

If there is no direct transfer of electrons from glucose to oxygen then what is used?

Electron shuttles are used

name two types of fermentation and describe what happens in them

Ethanol Fermentation (yeast) Input: 2 pyruvates from glycolysis 2 pyruvates make 2 acetaldehydes. 2 carbon dioxide (the carbon dioxide released causes the bubbles in bread) 2 acetaldehyde is converted into ethanol which allows NADH to be reduced back to NAD+ Lactic Acid Fermentation (animals → muscle cells) Input: 2 pyruvates from glycolysis 2 pyruvates converted into 2 lactates which allows NADH to be reduced abc to NAD+ The buildup of lactate, like when doing springs, can make you feel nauseous. so this happens because when you're exercising, you evenually use up all your oxygen so the only thing you can do is use fermentation because this doesn't require oxygen. as you do more and more lactic acid fermenation, you feel more nauseus

FAD = _____ & ______ FADH2 = _____ & ______ Bank: oxidized, reduced, empty electron shuttle, full electron shuttle

FAD = oxidized, empty electron shuttle FADH2 = reduced; full electron shuttle

define fermentation and explain what happens

Fermentation: main goal→ NADH is oxidized back into NAD+ so it can accept more electrons. This RECYCLES NAD+ molecules for GLYCOLYSIS to keep FUNCTIONING; in order for glycolysis function it needs to get the NAD+ and get rid of the NADH so it can be the NAD+ it needs. So in glycolysis, 2 NADH were made and now since there's no oxygen it can't continue to the citric acid cycle. It has energy but it needs to get RID of it → OXIDIZE IT! From glycolysis there are 2 pyruvates. Now, pyruvate will be reduced into another compound (waste product). Depending on WHAT the pyruvate is reduced to is the TYPE of fermentation Converting this pyruvate causes NADH to reduced back to NAD+

explain what happens here in reference to oxidation and reduction C6H12O6 +6O2 → 6 CO2 + 6H2O + ATP

Glucose is oxidized because it loses electrons (oxygen, which is negative, is leaving) Oxygen is reduced because it gains electrons

define glycolysis and explain what happens

Glycolysis: begins the degradation process by breaking glucose into 2 molecules of a compound called pyruvate. Can occur aerobically (with oxygen) or anaerobically (without oxygen, requiring fermentation in cytoplasm) Happens in ALL organisms because it doesn't occur in the mitochondria 10 reactions occur that are each mediated by an enzyme(small so no explosion) 2 ATP are required because you need to reconfigure bonds to get out more energy After glucose splits into pyruvate, each pyruvate produces 2 ATP, so there's 4 ATPs total but the NET is 2 because it required an input of 2

inputs and outputs for glycolysis

Inputs 1 glucose (6 C) 2 NAD+ 2 ATP Outputs 2 Pyruvate (3C) 2 NADH 4 ATP

inputs and outputs for fermentation

Inputs 2 pyruvate 2 NADH Outputs 2 NAD+ Various carbon (depends on type of fermentation) Waste products (depends on type of fermentation)

An electron will ________ potential energy when it shifts from a less electronegative atom to a more electronegative atom

LOSE because moving to a MORE electronegative atom means it's MORE NEGATIVE!!!! also think of ETC diagram with all the proteins moving in a negative line. each one has less potential energy than the previous

Does pyruvate have more or less potential energy than glucose? Explain

Less because it has less bonds and energy is released when bonds are broken

define and describe link step

Link Step: pyruvate turns into Acetyl CoA Pyruvate heads into mitochondria via transport protein 1 carbon dioxide is lost PER pyruvate...now pyruvates are only 2 carbons long and has been converted into a acetyl group 1 NADH made PER pyruvate from the release of the carbon dioxide Coenzyme A is attached to the pyruvate that was just the acetyl group Now you have Acetyl CoA → this is what will enter the citric acid cycle

Which of the four phases produce carbon dioxide

Link reaction and krebs cycle (remember, pyruvate loses its oxygen?) also ethanol fermentation

Which phases of cellular respiration occur in the mitochondria?

Link reaction, krebs cycle, oxidative phosphorylation

Given that cells can't store ATP for long periods of time, how do they store energy? And why is this place beneficial?

Lipids! They have lots of available energy and can pack tightly together. They are large molecules and don't affect osmotic potential.

inputs and outputs for citric acid cycle

Multiply by 2 because 2 pyruvates in 1 glucose Inputs 1 Acetyl-CoA (2 C from pyruvate) 3 NAD+ 1 FAD+ 1 ATP Outputs 2 carbon dioxides 3 NADH 1 FADH2 1 ATP

inputs and outputs for link step

Multiply by 2 because 2 pyruvates in 1 glucose Inputs 1 pyruvate 2 NAD+ Outputs 1 acetyl-CoA (2 C from pyruvate) 1 carbon dioxide 2 NADH

NAD is a ____ NADH is a ____ word bank substrate product

NAD is a product NADH is a substrate

NAD+ = _____ & ______ NADH = _____ & ______ Bank: oxidized, reduced, empty electron shuttle, full electron shuttle

NAD+ = oxidized, empty electron shuttle NADH = reduced; full electron shuttle

explain what happens here in reference to oxidation and reduction Na + Cl = Na+ + Cl-

Na becomes oxidized, losing its electrons, becoming positive (reducing agent) Cl becomes reduced, gaining the electrons from Na, becoming negative (oxidizing agent)

Is the pyruvate molecule likely to move across the mitochondrial membranes by diffusion?

No, it's polar so it needs to move through a protein channel

Which of the four phases of cellular respiration produce water?

Oxidative phosphorylation

Which of the four phases of cellular respiration require oxygen?

Oxidative phosphorylation (no oxygen for glycolysis and krebs!!!! But oxygen needs to be present to make Acetyl CoA)

define and describe oxidative phosphorylation

Oxidative phosphorylation: electron transport chain accepts electrons (often via NADH) from the breakdown products of the first 2 stages and passes these electrons from molecule to molecule. At the end of the chain, the electrons are combined with molecular oxygen and H+, forming water. The energy released at each step of the chain is stored in the form the mitochondria can use to make ATP from ADP. This is called oxidative phosphorylation because it's powered by redox reactions of the electron transport chain Part 1: electron transport chain: Reduced electron shuttles (NADH and FADH2) are oxidized at the electron transport chain: complexes of proteins embedded in the inner mitochondrial membrane Electrons flow through the proteins in this chain, driven by the increasing electronegativity of the members of the electron transport chain. Free energy decreases along the chain This is why proteins in the chain are always set up in the same order with increasing electronegativities...to pull the electrons through As the electrons move through the chain, the free energy they release is used to pump protons (H+) through the ETC proteins from the matrix into the intermembrane space Because these protons are IONS, they can't move through the phospholipid bilayer; thus a high energy concentration gradient is created with all the hydrogen ions Oxygen serves as the terminal electron acceptor. When oxygen acquires 4 electrons and 2 protons, it's converted to WATER which is released as a waste product. Oxygen is like a magnet. The pyruvate is not allowed into the mitochondria unless oxygen is available The oxidized electron carriers (NAD+ and FAD+) are fed back into glycolysis and the citric acid cycle. In glycolysis, NAD+ is made into NADH that oxidative phosphorylation can use again. In the citric acid cycle, NAD+ and FAD+ are made into NADH and FADH2 to be used in oxidative phosphorylation Part 2: time for chemiosmosis Uses energy from the concentration gradient formed to move H+ ions through ATP synthase, an enzyme, to create ATP ETC establishes a proton (aka electrochemical) gradient Protons can only diffuse back into the matrix via a protein CHANNEL because of phospholipid bilayer ATP synthase is the ONLY protein channel available in the inner membrane As protons diffuse through ATP synthase, the free energy that is released is used to catalyze ATP formation from ADP and free phosphate groups → this is OXIDATIVE PHOSPHORYLATION

when electrons move closer to a more electronegative atom, energy is ___

RELEASED

how is ATP produced in glycolysis and the citric acid cycle

Substrate - level phosphorylation: This is how the ATP needed for glycolysis and the citric acid is produced. In these two cycles ATP is needed as in input. However, in oxidative phosphorylation, the majority of the ATP is produced

The more electronegative an atom is, the more _____ required to take an _____ away from it.

The more electronegative an atom is, the more energy required to take an electron away from it.

what are electron shuttles and what different forms do they exist in

These are compounds that store electrons from food Exist in oxidized (NAD+, empty electron shuttle) and reduced (NADH, full electron shuttle) forms This is a coenzyme and an oxidizing agent NAD+ traps electrons from glucose/food molecules through dehydrogenase: enzyme that removes a pair of hydrogen atoms from the substrate. This converts NAD+ to NADH

What molecules are produced as the hydrogen ions and electrons are removed from NADH and FADH2?

Water and ATP

what happens after link step?

citric acid cycle!

Electron Transport Chain:

consists of a number of molecules (mostly proteins) built into the inner membrane of the mitochondria of eukaryotic cells (plasma membrane in prokaryotes)

which of the following statements correctly describes a metabolic effect of cyanide, a poison that blocks the passage of electrons along the electron transport chain? a. the pH of the intermembrane space bcomes much lower than normal b. alcohol would build up in themitochondria C. NADH supplies would be exhaused, and ATP syntehssi would cease d. no proton gradient would be produced, and ATP synthesis would cease

d. no proton gradient would be produced, and ATP synthesis would cease

Oxidizing agent:

electron acceptor

Reducing agent:

electron donor

explain how ATP synthase operates

in a series of redox reactions, H+ is pumped into intermembrane space, and electrons pass to O2. Proton-motive force drives H+ through ATP synthase to make ATP

inputs and outputs for oxidative phosphorylation

inputs 10 NADH 2 FADH2 O2 outputs 32-34 ATP - In the decoupling (separate!!!) of glucose oxidation and oxidative phosphorylation, you can lose energy as everything is transferred. Roughly 3 ATP per NADH and 2 ATP per FADH2. Not as much FADH2 because this only comes in in the citric acid cycle. NADH is produced in the citric acid cycle AND glycolysis H2O 10 NAD+ NAD+ is a product 2 FAD+

brown fat, whcih is found in newborn infants and hibernating mammals, has uncoupler proteins that, when activated, make the inner mitochondrial membrane leaky to H+. what is the function of brown fat?

it lowers the pH of the intermembrane space, whcih results in the production of more ATP per gram that is produced by the oxidation of glucose or regular fat tissue BECAUSE THE LOWER THE PH THE MORE H IONSSSS

Oxidation:

loss of electrons from one substance

Substrate - level phosphorylation:

mode of ATP synthesis when an enzyme transfers a PHOSPHATE GROUP from a substrate molecule to ADP, rather than adding an inorganic phosphate ADP, as in oxidative phosphorylation

why are metabolic reactions multi-stepped

otherwise explosion!

Is the removal of hydrogen ions and electrons from NADH and FADH2 oxidation or reduction?

oxidation

what happens after citric acid cycle?

oxidative phosphorylation

Aerobic respiration:

oxygen is consumed as a reactant along with the organic fuel. This is the most efficient catabolic pathway WAY MORE EFFICIENT THAN ANAEROBIC 40% efficient in terms of converting chemical energy in glucose into chemical energy in ATP. The other 60% is lost as HEAT→ this is good! Otherwise you would be cold :(

Fermentation:

partial degradation of sugars/organic fuel that occurs without the usage of oxygen

Redox reactions (oxidation reduction reactions):

transfer of 1 or more electrons from one reactant to another.

Cellular respiration:

used to refer to aerobic processes (although technically includes anaerobic as well). The oxidation of glucose and other molecules into food.

Anaerobic respiration:

when some prokaryotes use substances other than oxygen as reactants, harvesting chemical energy