CH 2 OH

CH2OH

OH

O

OH

OHOH

GLYCOLYSIS

GLUCOSE

Kinase ATPADP

OHOH

OH

OH

CH2O(P)O

GLUCOSE-6-P

Isomerase

CH2O(P)O

CH2OH

OH

OH

FRUCTOSE-6-P

Kinase ATPADP

FRUCTOSE-1,6 Di-PhosphateCH2O(P)

OCH2O(P)

OH

OH

Adolase

P-Glyceraldehyde (3C) DiOH Acetone Phosphate (3C)

1, 3, P-Glyceric acid

ADP + PiATP

NAD+

NADH2Kinase

2 P-Glyceric acid

Isomerase

Enol Pyruvate

ADP + PiATPKinase

Pyruvate

CH3-C-COOH

O

NAD+ NADH2

CO2Dehydrogenase

Coenzyme AAcetyl CoA

CH3-C-S-CoA

O

x2

x2

PYRUVATE ACTIVATION

Oxaloacitic Acid (4C)

COO- -CH2-C-COO-

O

Citric Acid

Isocitric Acid (6C)

ά Ketoglutarate Acid (5C) COO- -CH2-CH2-C-COO-

O

Succinyl CoA

Succinate

Fumorate Acid

Malate Acid

Tricarboxylic Acid Cycle (TCA/ Krebs Cycle)

NAD+

NADH2

NAD+

NADH2

GDP+

GTP

FAD+

FADH2

NAD+

NADH2

CO2

CO2

Pyruvate

FERMENTATION

CH3-C-COO-

O

CH3-C-COO-

OH

Lactic Acid

Pyruvate Acetaldehyde ETOH

PyruvatePyruvate

+

CO2

H

CH3-C-COO-

O

CH3-C-COO-

O

CH3-C-COO-

O

NADH NAD+

NADH NAD+

NADH NAD+

Homolactic

Ethanolic

2, 3 Butanediolic

CH3-C

O

HCH3-CH2-OH

CH3-C

O

C-CH3

O

CO2CO2

2NADH

2NAD+

CH3-C-C-CH3

O

OH

HAcetoin

2NADH

2NAD+

CH3-C-C-CH3

H H

OH OH2, 3, Butanediol

ELECRON TRANSPORT SYSTEM (RESPIRATION / OXIDATIVE PHOSPHORYLATION

FMN Fes CoQ Cyt b Cyt c Cyt a1 Cyt a3

Ox Red Ox Red Ox Red Ox

ADP ATP

ATPase

ADP ATP ADP ATPATPase ATPase

H H H

+3

+3+2

+2

H2

H2O

O2

Red Ox Red Ox Red Ox Red

GLYCOLYSIS

1 GLU + 2ATP + 2NAD = 2PYR + 4ATP + 2NADH2

NET GAIN = 2 ATP

PYRUVATE ACTIVATION

2 PYR + 2NAD + 2CoA = Acetyl CoA + 2NADH2 + 2CO2

2, 3 Butanediolic Fermentation2PYR + 2NADH Acetoin + NAD + 2 CO2 +2NADH 2, 3 Butanediol + 2NADNET GAIN = 4 NAD

ETS

16 NADH from glycolysis need to be reduced.

TCAAcetyl CoA + 3NAD + 1 FAD + 1GTP = 3 NADH + 1FADH2 + GTP + CO2

MULTIPLY THE ABOVE BY TWO

*First energy-producing step

TOTAL GAIN:8 H+

2 GTP

Ethanolic FermentationPYR + NADH Acetaldehyde + NAD + CO2 +NADH ETOH + NADNET GAIN = 2 NAD

Homolactic FermentationPYR + NADH Lactic Acid + NAD NET GAIN = 1 NAD

SO4 NO2

H2S NH3

Anaerobic phosphorylation end-products (instead of H2O)

Glycolysis takes place in the cytoplasm. It converts glucose, fructose, or galactose into 2 molecules of pyruvate plus 2 ATP. This process uses 2 NAD (an electron acceptor), which becomes reduced to NADH. We need to get it back to NAD or glycolysis will stop. The pyruvates are then taken to the mitochondria to go through the Kreb’s (TCA) cycle to generate ATP.

GLYCOLYSIS


NET GAIN = 2 ATP

2

Glycolysis

• Glycolysis is like a gumball machine in the cytoplasm. You put one sugar molecule in, add 2 pennies (ATP) and get out two gumballs (pyruvate). The gumball machine also gives your two pennies back, plus an additional two pennies! It takes money to make money, right?

• So now you have a net profit of 2 pennies to spend on energy, plus the two gumballs that you can take to the mitochondria to convert to 2 more special pennies (GTP) that can only be used for certain games in the body (protein synthesis and gluconeogenesis).

3

Glycolysis• During glycolysis, we generate hydrogen (H+),

which is a waste product that we have to get rid of, but almost no one wants to carry that burden.

• There is a guy named NAD who is willing to accept this burden. When he takes on the H+, he is reduced. If his H+ burden is removed by someone else, he feels good, and is oxidized!

• All of NAD’s brothers are also named NAD. It takes 2 NAD brothers to come to the glycolysis gumball machine and take on the burden of the H+. They are now called NADH.

• Right now, you need to take your 2 gumballs (pyruvate) to the mitochondria so you can use the Kreb’s Cycle to convert them into special pennies.

• The two NADH brothers will wait for you to complete the Kreb’s Cycle, so you can escort them to the Electron Transport Chain, where their H+ burdens will be lifted. 4

The Kreb’s Cycle occurs in the mitochondria, and requires oxygen. It takes one of the pyruvate molecules we got from glucose, and one acetate (in the form of Acetyl CoA) from the break down of carbohydrates, fats and proteins, and then the Kreb’s Cycle generates 2 GTP (similar to ATP). The waste product is carbon dioxide.

Like glycolysis, it uses NAD and reduces it to NADH. The NADH is then sent to the Electron Transport System so it can be converted back to NAD so glycolysis can continue.

Kreb’s Cycle or Citric Acid Cycle or Tricarboxylic Acid Cycle (TCA)Acetyl CoA + 3NAD + 1 FAD + 1GTP = 3 NADH + 1FADH2 + GTP + CO2 MULTIPLY THE ABOVE BY TWO

TOTAL GAIN: 8 H+ and 2 GTP

5

Kreb’s Cycle

• Now you have taken your two gumballs from glycolysis (pyruvate) and entered the mitochondria.

• You see your neighbor, who does not use sugar. He uses another process which breaks down carbohydrates, fats and proteins elsewhere in the body, and generates Acetyl CoA instead of pyruvate.

• You put one of your pyruvate gumballs into a Kreb machine, along with one of his Acetyl CoA molecules.

• Three more NAD brothers, plus their cousin FAD have to come in to bear the burdens of the four H+ that will be generated per pyruvate gumball (8 H+ for both pyruvates are generated). 6

Kreb’s Cycle

• For all this, you will get only one special penny (GTP) per gumball. Since you have two gumballs you get 2 GTP.

• You will now have two special pennies, but you now have 8 new people who are carrying your H+ burden, in addition to the 2 people who are waiting for you at the door from the gumball machine.

• You need to take all of them to the Electron Transport Chain so someone else can lift their burden and they can get back to work at the gumball machine again.

7

The Electron Transport System (aka oxidative phosphorylation, or cellular respiration) also takes place in the mitochondria. Here, the NADH molecules from glycolysis and the TCA cycle are oxidized back to NAD so glycolysis can continue. It also generates 3 more ATP. When this system is performing in the presence of oxygen, oxygen is consumed and the waste product is water. When it is done anaerobically (such as in some bacteria), sulfate is used as the H+ acceptor and the waste product is hydrogen sulfide (will show a black precipitate on culture media). If the bacteria does not have sulfate, it will use nitrite as the electron acceptor, and the waste product is ammonia, which causes a color change if there is a pH indicator in the culture media.

8

ETS

8 NADH and 2 FADH from glycolysis need to be reduced.

ETS


Electron Transport Chain (cellular respiration)

• When the NADH brothers enter this area of the mitochondria, there is a hallway lined with several people.

• The first NADH brother gives his H+ burden to the first person (FMN). That makes him oxidized to NAD again, but the person that took the H+ is now reduced, and he does not want that burden either, so he passes it to the next person in line (FeS). Now FMN becomes oxidized and the second person is reduced. FeS passes the burden to CoQ and so on, to the end of the line.

9

Electron Transport Chain (cellular respiration)

• When they finally get to the end of the line, they are greeted by the heavenly oxygen angel. She is so strong, she can take and hold 2 burdens at once.

• When she takes the H+ burden from two NADH brothers, she becomes water. The water will be exhaled. We need to inhale some more heavenly oxygen angels to keep this process going.

• Now the NAD brothers have been oxidized. They feel so good, they want to go back to work to help again with bearing the H+ burden.

10

Cell Respiration Summary

• The summary equation for cellular respiration is:

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O

glucose + oxygen → carbon dioxide + water

11

What if there is no more oxygen?

• Some bacteria, molds, and yeasts can still use the ETC when there is no oxygen. At the end of the hand-shaking line, they have either sulfate or nitrite.

• If they have sulfate, instead of taking the H+ and turning into water to be exhaled, it turns into hydrogen sulfide (H2S), a waste product which shows up as a black color on a Petri dish.

• If they have nitrite, they will turn into ammonia, a waste product which has a high pH.

12

What if there is no more oxygen?

• Humans do not have sulfate or nitrite. They can only use oxygen as the final electron acceptor in the electron transport chain (cellular respiration).

• Muscle cells use a lot of energy, so they are able to run out of oxygen yet still carry out cellular respiration by using fermentation to take the H+ burden off the NAD brothers so they can go back to work for the gumball glycolysis machine and the Kreb’s machine. Muscles are the only human cells that can do this.

13

Fermentation Pathways• When no oxygen is present (such as in muscles during

sprinting), the NADH molecules that were generated from glycolysis and the TCA cycle cannot use the electron transport chain to be converted back to NAD. Instead, they use one of three fermentation pathways.

• Homolactic• Ethanolic• 2, 3, Butanediolic

• In the homolactic pathway (used by humans), the H+ from NADH is donated to pyruvate, converting it to the waste product: lactic acid. The NAD has now been regenerated so glycolysis can continue. By breathing heavily, oxygen is added to lactic acid, converting it to glucose. The lactic acid could also be carried by the bloodstream to the liver, where it is converted back to pyruvate. Therefore, increasing circulation and oxygen helps eliminate lactic acid build-up (ultrasound or massage therapy for sore muscles helps).

14

Ethanol Fermentation• The ethanol fermentation pathway

also uses glycolysis, but the pyruvate is then converted to ethanol and carbon dioxide.

• Yeasts use this pathway to create beer, and cause the rising of bread dough.


15

2, 3, Butanediole Pathway

Butanediol fermentation uses 2 pyruvate molecules and the waste product is 2, 3, butanediol. Use of this pathway is typical for Enterobacter (a type of coliform bacteria) and is tested for by using the Voges–Proskauer (VP) test. If the unknown culture has a positive VP test, we know it might be this organism.


16

CH2OH

OH

O

OH

OHOH

GLYCOLYSIS

GLUCOSE

Kinase ATPADP

OHOH

OH

OH

CH2O(P)O

GLUCOSE-6-P

Isomerase

CH2O(P)O

CH2OH

OH

OH

FRUCTOSE-6-P

Kinase ATPADP

FRUCTOSE-1,6 Di-PhosphateCH2O(P)

OCH2O(P)

OH

OH

Adolase

P-Glyceraldehyde (3C) DiOH Acetone Phosphate (3C)

1, 3, P-Glyceric acid

ADP + PiATP

NAD+

NADH2Kinase

2 P-Glyceric acid

Isomerase

Enol Pyruvate

ADP + PiATPKinase

Pyruvate

CH3-C-COOH

O

NAD+ NADH2

CO2Dehydrogenase

Coenzyme AAcetyl CoA

CH3-C-S-CoA

O

x2

x2

PYRUVATE ACTIVATION

Oxaloacitic Acid (4C)

COO- -CH2-C-COO-

O

Citric Acid

Isocitric Acid (6C)

ά Ketoglutarate Acid (5C) COO- -CH2-CH2-C-COO-

O

Succinyl CoA

Succinate

Fumorate Acid

Malate Acid

Tricarboxylic Acid Cycle (TCA/ Krebs Cycle)

NAD+

NADH2

NAD+

NADH2

GDP+

GTP

FAD+

FADH2

NAD+

NADH2

CO2

CO2

Pyruvate

FERMENTATION

CH3-C-COO-

O

CH3-C-COO-

OH

Lactic Acid

Pyruvate Acetaldehyde ETOH

PyruvatePyruvate

+

CO2

H

CH3-C-COO-

O

CH3-C-COO-

O

CH3-C-COO-

O

NADH NAD+

NADH NAD+

NADH NAD+

Homolactic

Ethanolic

2, 3 Butanediolic

CH3-C

O

HCH3-CH2-OH

CH3-C

O

C-CH3

O

CO2CO2

2NADH

2NAD+

CH3-C-C-CH3

O

OH

HAcetoin

2NADH

2NAD+

CH3-C-C-CH3

H H

OH OH2, 3, Butanediol

ELECRON TRANSPORT SYSTEM (RESPIRATION / OXIDATIVE PHOSPHORYLATION

FMN Fes CoQ Cyt b Cyt c Cyt a1 Cyt a3

Ox Red Ox Red Ox Red Ox

ADP ATP

ATPase

ADP ATP ADP ATPATPase ATPase

H H H

+3

+3+2

+2

H2

H2O

O2

Red Ox Red Ox Red Ox Red

GLYCOLYSIS


NET GAIN = 2 ATP

PYRUVATE ACTIVATION

2 PYR + 2NAD + 2CoA = Acetyl CoA + 2NADH2 + 2CO2


ETS


TCAAcetyl CoA + 3NAD + 1 FAD + 1GTP = 3 NADH + 1FADH2 + GTP + CO2

MULTIPLY THE ABOVE BY TWO

*First energy-producing step

TOTAL GAIN:8 H+

2 GTP


Homolactic FermentationPYR + NADH Lactic Acid + NAD NET GAIN = 1 NAD

SO4 NO2

H2S NH3

Anaerobic phosphorylation end-products (instead of H2O)

ATP• Adenosine triphosphate (ATP) is used in cells

as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer.

• ATP transports chemical energy within cells for metabolism. It is one of the end products of phosphorylation and cellular respiration and used in many cellular processes, including muscle contraction, motility, and cell division.

• One molecule of ATP contains three phosphate groups which provide energy. When ATP is used, it loses a phosphate and is reduced to ADP (diphosphate).

• Metabolic processes that use ATP as an energy source will cause it to be reduced to ADP, so it will use other metabolic processes to convert the ADP back into ATP, so it is continuously recycled.

• Guanosine triphosphate (GTP) is similar to ATP but can only be used as a source of energy for protein synthesis and gluconeogenesis.

18

ATP Molecule

19

Amino Acids build proteins

Building blocks of protein, containing an aminogroup and a carboxyl groupAmino acid structure: central C; amino group,acid group, and variable group

a) AMINO ACIDS are MONOMERS (building blocks) of protein. They are tiny carbon molecules, made of just a carbon atom and a few other atoms.

There are only 22 standard types of amino acids in the human body (20 of them are involved in making proteins). Nine of these are essential amino acids, meaning that we have to get them in the diet. We can synthesize the others.

Amino acids are like beads on a necklace. Each bead is an amino acid, and the whole necklace is the protein. A bunch of the same types of necklaces (proteins) woven together makes up our tissues.

21

Amino AcidsEssential Nonessential

Histidine Alanine

Leucine Arginine

Isoleucine Asparagine

Lysine Aspartic acid

Methionine Cysteine

Phenylalanine Glutamic acid

Threonine Glutamine

Tryptophan Glycine

Valine Ornithine

Proline

Selenocysteine

Serine

Tyrosine 22

Where do the molecules go when you lose weight?

• Think of fat as essentially a long-chain hydrocarbon CH3-(CH2)n-CH3. When your body uses that fat as fuel (either because you need fuel to exercise, or because you're not eating enough new fuel to support what you're doing), it burns that fat to extract the energy from it. That "burn" isn't a metaphor. The chemistry that your body does is exactly equivalent to literally burning it, just under more controlled conditions.

23


• So, that hydrocarbon undergoes a controlled combustion with oxygen (O2) to produce a lot of energy, water (H2O), and carbon dioxide (CO2).

Or, in chemical form:CH3-(CH2)n-CH3 + (3/2n+7/2)O2 ----> (n+2) CO2 + (n+3) H2O + Energy

24


• So the carbon in the hydrocarbon goes to carbon dioxide and the hydrogen goes to water. But most of the mass of the hydrocarbon is carbon, so most of the mass gets converted to carbon dioxide, which is a gas and gets breathed out.

• Now this is incomplete, because lipids and fat really aren't just hydrocarbons. They have phosphates and nitrogen and other things too, and those parts don't get converted to gases for excretion. Excess nitrogen gets converted to urea, for example, which gets excreted in the urine. And protein produces a lot more impurities when it gets broken down (though generally the body prefers to recycle proteins rather than burn them for energy).

• But really, the way you lose most of your weight is just by breathing it off.

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CH 2 OH

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