Ch.9

Front 1

Aero-

Back 1

air

Front 2

An-

Back 2

not

Front 3

Chemi-

Back 3

Chemical

Front 4

glyco-

Back 4

Sweet

Front 5

-lysis

Back 5

split

Front 6

Acetyl CoA

Back 6

The entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme

Front 7

Aerobic

Back 7

Containing oxygen, referring to an organism, environment, or ceullar process that requires oxygen

Front 8

Alcohol Fermentation

Back 8

The conversion of pyruvate to carbon dioxide and ethyl alcohol

Front 9

ATP synthase

Back 9

Acluster of several membrane proteins found in the mitochondrial crista thatfunction in chemiosmosis with adjacent electron transport chains, using theenergy of a hydrogen ion concentration gradient to make ATP. ATP synthasesprovide a port through which hydrogen ions diffuse into the matrix of a mitochondrion.

Front 10

Cellular Respiration

Back 10

The most prevalent and efficient catabolic pathway for theproduction of ATP, in which oxygen is consumed as a reactant along with the organic fuel.

Front 11

Chemiosmosis

Back 11

An energy-coupling mechanism that uses energy stored in theform of a hydrogen ion gradient across a membrane to drive cellular work, suchas the synthesis of ATP.

Front 12

Citric Acid Cycle

Back 12

Achemical cycle involving eight steps that completes the metabolic breakdown ofglucose molecules to carbon dioxide; occurs within the mitochondrion; thesecond major stage in cellular respiration.

Front 13

Electron Transport Chain

Back 13

A sequence of electron carrier molecules (membrane proteins)that shuttle electrons during the redox reactions that release energy used tomake ATP.

Front 14

Fermentation

Back 14

A catabolic process that makes a limited amount of ATP fromglucose without an electron transport chain and that produces a characteristicend product, such as ethyl alcohol or lactic acid.

Front 15

Glycolysis

Back 15

Thesplitting of glucose into pyruvate. Glycolysis is the one metabolic pathwaythat occurs in all living cells, serving as the starting point for fermentationor aerobic respiration.

Front 16

Lactic Acid Fermentation

Back 16

The conversion of pyruvate to lactate with no release ofcarbon dioxide.

Front 17

NAD+

Back 17

Nicotinamideadenine dinucleotide, a coenzyme present in all cells that helps enzymestransfer electrons during the redox reactions of metabolism

Front 18

Oxidation

Back 18

Theloss of electrons from a substance involved in a redox reaction.

Front 19

Oxidative Phosphorylation

Back 19

Theproduction of ATP using energy derived from the redox reactions of an electrontransport chain.

Front 20

Redox Reaction

Back 20

Achemical reaction involving the transfer of one or more electrons from onereactant to another; also called oxidation-reduction reaction.

Front 21

Reduction

Back 21

The addition of electrons to a substance involved in a redoxreaction.

Front 22

Substrate-level Phosphorylation

Back 22

Theformation of ATP by directly transferring a phosphate group to ADP from anintermediate substrate in catabolism

Front 23

Describe Cell Respiration

Back 23

--- Cell respiration is a series of chemicalreactions in which the overall goal is to break down large, energy richmacromolecules and release the stored energy in order to make many ATPmolecules which can each be used to power cell jobs

--- It is a catabolic pathway.

Front 24

How do Redox reactions work within Cell Respiration?

Back 24

Redox (oxidation–reduction) reactions play animportant role in cell respiration as electrons are stripped from molecules andtransferred to otherso

Front 25

Oxidation (within Cellular Respiration)

Back 25

Oxidation is the loss of electrons and moleculesthat undergo oxidation are said to be oxidized and are reducing agents

In generation, oxidation releases energy fromchemical bonds and reduction stores energy agment

Front 26

Reduction (within Cellular Respiration)

Back 26

Reduction is the gain of electrons and moleculesthat undergo reduction are said to be reduced and are oxidizing agents

Front 27

Summary Equation for Cell Respiration (does not happen in one reaction however)

Back 27

C6H12O6 + 6O2 -> 6CO2 + 6H2O + ATP + HEAT

Front 28

The Major steps of Cell Respiration are:

Back 28

1) Glycolysis

2) Citric Acid Cycle

3) Electron Transport Chain

Front 29

1) Glycolysis (& steps)

Back 29

--- Occurs in cytoplasm

--- Breaks glucose into 2 molecules of pyruvate --- Initial series of endergonic reactions requiringATP

--- Second series of exergonic reactions makes a net2 molecules of ATP for every glucose

--- ATP is made by substrate level phosphorylation

--- Some electrons from glucose are also transferredto electron shuttle NAD+,, reducing it to NADH with the help ofdehydrogenase

Front 30

2) Citric Acid Cycle

Back 30

--- Occurs in the mitochondrial matrix

--- citric acid cycle begins, pyruvate isfirst converted into acetyl Co-A in pre-citric acid step

---A molecule of carbon dioxide is produced

---More electrons are transferred to NAD+to make NADH

---Co-enzyme A helps the formation of acetyl Co-A

---The citric acid cycle joins acetyl Co-A to a 4carbon molecule called oxaloacetate to form the 6 carbon molecule citrate

---Series of reactions converts citrate back intooxaloacetate but in the process:

---More carbon dioxide is produced

---More electrons are shuttled to form NADH andFADH2 (reduced form of a different electron shuttle, FAD)

---Some ATP is made by substrate levelphosphorylation

--- By end of citric acid cycle, all the originalenergy of glucose has been released either to make ATP in glycolysis or thecitric acid cycle or carried in the electrons being shuttled by FADH2or NADH

Front 31

3) Electron Transport Chain

Back 31

---Series of carrier molecules embedded in innermembrane of mitochondria

--- Electron shuttles NADH and FADH2 dropoff their electrons (becoming oxidized to NAD+ and FAD) and reducingthe carrier molecules

---In a series of redox reactions, carriermolecules pass the electrons down the chain until they are received by the finalelectron acceptor, oxygen

---oxygen plus the electrons plus H+become water

---The role of this oxygen is the reason aerobicorganisms need to breath oxygen

Front 32

Each redox reaction in the chain allows:

Back 32

some energy to be released which can be used topump H+ from the matrix to the intermembrane space

--- This build up of H+ stores potentialenergy ----The H+ ions are allowed to flow backdown their concentration gradient, through the inner membrane into the matrixbut only through the enzyme ATP synthase

---ATP synthase can then be powered to make ATPfrom ADP and inorganic phosphate groups by oxidativephosphorylation

Front 33

Chemiosmosis is the process of:

Back 33

Building up of the H+ gradient inorder to do a job—the job in this case is the make the ATP

--- The vast majority of ATP from cell respirationis made during the electron transport chain stage

Front 34

The summary equation for cellular respiration:

Back 34

Glucose + Oxygen --> CO2 + H2O +energy (ATP & Heat)

Front 35

Define oxidation and reduction and give examples of a redox reaction

Back 35

Oxidation is the loss ofelectrons from a molecule. Reduction isthe gaining of electrons. In cellularrespiration, glucose is oxidized to carbon dioxide as electrons are taken awayfrom it and given to oxygen which is reduced.

Front 36

Name the 3 main stages of cellular respiration and state the specific region in the cell where each stage occurs:

Back 36

1. Glycolysis: cytoso

2. Citric acidcycle: mitochondrial matrix

3. Electrontransport chain: within inner mitochondrialmembrane

Front 37

Compounds used in Glycolysis:

Back 37

Used: Glucose, NAD+

Produced: Water, NADH

Both: ATP, ADP + Pi,

Front 38

Compounds in Pre-Citric Acid Cycle:

Back 38

Used: NAD+

Produced: Carbon Dioxide, NADH

Front 39

Compounds in Citric Acid Cycle:

Back 39

Used: ADP + Pi, NAD+

Produced: Carbon Dioxide, ATP, NADH

Front 40

Compounds in the Electron Transport Chain

Back 40

Used: Oxygen, ADP + Pi, NADH

Produced: Water, ATP, NAD+

Front 41

Describe the role of NAD+ and FAD in cellular respiration

Back 41

These molecules serve aselectron shuttles or carriers. Theyoxidize more complex molecules such as glucose and take those electrons to theelectron transport chain in order to allow the extraction of energy in a slow,controlled manner which makes the maximum amount of ATP molecules.

Front 42

Explain why the Citric Acid Cycle is called a cycle

Back 42

Overall, it is a cyclebecause the sugar that begins the cycle by combing with acetyl CoA will eventually be made again bythe end of the cycle. Several stepsoccur in which carbon dioxide is produced and high enegy electrons are given toelectron shuttles (NAD+ and FAD) for use in the ETC and ATP is made bysubstrate level phosphorylation. Eventually, the products of these steps regenerates the same sugar to beused again as the cycle turns again.

Front 43

In general terms, explain what chemiosmosis is and how it allows the synthesis of ATP by oxidative phosphorylation

Back 43

Chemiosmosis is a generalterm used to describe when a proton (H+) gradient is developed andthen allowed to do some type of work. Incellular respiration, it is the gradual passing of electrons between carriermolecules embedded in the inner membrane of the mitochondria that allow protonsto be pumped into the intermembrane space. Once this proton gradient is built up, protons flow back into themitochondrial matrix only through places containing the enzyme ATPsynthase. The energy gained from protonsgoing from areas of high to low concentration is used to make ATP by oxidativephosphorylation. In this particularcase, the “work” done by chemiosmosis is the making of ATP.

Front 44

In overall terms, describe what is occuring in cellular respiration and why it is so wital for ogranisms

Back 44

Organisms have countlessenergy needs in their cells such as building larger molecules from smaller,pumping ions against their concentration gradients in and out of cells,contracting muscle proteins, etc. Each of these activities requires only asmall bit of cellular energy. Largecomplex food molecules such as glucose have a great deal of chemical energy intheir bonds. To use one of these molecules to power each cell’s jobs would beoverkill and would waste most of the bond energy. Cellular respiration is a process that allowsthe gradual breakdown of all the bond energy in glucose and turns it into many,smaller packets of more usuable energy (ATP molecules).

Front 45

What are the pros and cons of fermentation to the organisms that can or can not use this pathway?

Back 45

A major pro offermentation is that it can occur without any oxygen present which opens up thepossibilities of environments in which organisms can live. With fermentation, a microbe can undergoglycolysis (with no need for a mitochondria nor oxygen) and generate 2molecules of ATP for energy needs. Themicrobe can then continue the glycolysis pathway as long as more glucose ispresent and the electron shuttle NAD+ has been regenerated eitherthrough the steps of alcohol or lactate fermentation

The cons of fermentationis that ONLY 2 molecules of ATP will be generated by glycolysis and only verysmall, less complicated organisms can survive on such a low ATP level. Having oxygen utlized and the entire cellrespiration pathway with the mitochondria will enable far larger energyharvesting from glucose and produce a higher amount of ATP molecules. .