CH. 6 METABOLISM OF PROKARYOTIC CELLS Both catabolic and anabolic chemical reactions occur. Both...

CH. 6METABOLISM OF

PROKARYOTIC CELLS

Both catabolic and anabolic chemical reactions occur.

Both oxidation and reduction chemical reactions occur.

TBL06_01: Comparison of two key aspects of cellular metabolism

How enzymes function

Ezymatic action

Figure 06.02: The mechanism of enzyme action

Figure 06.04: Metabolic pathways and enzyme inhibition

Oxidation-Reduction

Figure 06.05: Adenosine triphosphate and the ATP/ADP cycle

5.2The Catabolism of

Glucose

Glucose contains stored energy that can be extracted

• Metabolic pathways• Coupled reactions

Summary of respiration and fermentation

Glycolysis is the first stage of energy extraction

• Reactions of glycolysis• Metabolic pathway

ATP gain from glycolysisNADH formed

The Glycolytic pathway

The Krebs cycle extractsmore energy from pyruvate

• Pyruvate (Pyruvic acid) is changed to a 2 carbon acetyl in the transition stage.

A total of 8 NADH’s and 2FADH’s are gained starting with pyruvate, which includes the transition stage, and concludes with the production of OAA at the end of the Kreb’s Cycle.

A total of 2 ATP’s are made directly in the Kreb’s Cycle.

Summary of respiration and fermentation

Figure 06.08: The steps of the Krebs cycle

Figure 06.09: Summary of glycolysis and the Krebs cycle

THE ELECTRON TRANSPORT SYSTEM

A total of 34 ATP are produced here .

In bacteria, ETS occurs on the cell membrane

The ElectronTransport System

Electron Transport Systemof Eukaryotes

Figure 06.10: Oxidative phosphorylation in bacteria

Figure 06.MI01A: Assembly of F0F1 complex/ATP synthesis

The structure of ATP Synthase

Figure 06.11: The ATP yield from aerobic respiration

Figure 06.12: Carbohydrate, protein & fat metabolism

Fermentation produces ATP using an organic final electron

acceptor

• NAD+ is regenerated.• Lactic acid or many other organic acids are

produced as waste products.• Or a variety of alcohols and other

fermentation waste products are produced.• ATP is produced only in the glycolytic

pathway, along with 2 pyruvic acids and 2NADH’s.

Figure 06.13a: The relationship of fermentation to glycolysis

Figure 06.13b: Alcoholic fermentation

Figure 06.14: Variations in fermentation end products

Examples of fermentation with pyruvate as the intermediary

substrate

Figure 06.15: Cyanobacterial membranes

© Dr. Dennis Kunkel/Visuals Unlimited

REVIEW OF CELL RESPIRATION

C C C C C Cglucoseglucose NADNAD++ NADHNADH

C C Cpyruvatpyruvat

ee22

ADPADP ATPATP22 22

22 22

22lactatelactateNADHNADH NAD+NAD+

C C C

C C22ethanethan

olol++ 22COCO22

NADHNADH

NADNAD++

C C Cpyruvatpyruvat

ee

CoACoA

acetyl acetyl CoACoAC C

COCO22

C C Cpyruvatpyruvat

ee

acetyl acetyl CoACoAC C

Krebs

cycle

ATPATP

ADPADP

NADNAD++

NADHNADHFADFAD

FADHFADH22

33

33

NADHNADH NAD+NAD+

e-

H+

H+

H+

H+

H+H+H+ H+H+

H+

½ O22

H+

HO2

H+

FADHFADH22 FADFAD

ATAT

PP

ADAD

PP

Glucose + O2 CO2 + H20 + Energy

2 CO2 CO22

CoACoA

NADHNADH

Find:1. Fermentation2. Formation of acetyl

CoA3. Glycolysis4. ETC5. Kreb Cycle• Where in the cell

does each reaction take place

C C C C C C________________ NADNAD++ NADHNADH

C C C________________22 22 ________________

ADPADP ATPATP22 22

22 22 NADHNADH NAD+NAD+

C C C

C C22________________ ++ 22COCO22

NADHNADH

NADNAD++

CoACoA

______________________C C

COCO22

ATPATP

ADPADP

NADNAD++

NADHNADHFADFAD

FADHFADH22

33

33

NADHNADH NAD+NAD+

e-

H+

H+

H+

H+

H+H+H+ H+H+

H+

½ O22

H+

HO2

H+

2 x

FADHFADH22 FADFAD

____

____

ADAD

PP

(matrix(matrix))

2 CO2 CO22

CoACoA

NADHNADH

HH22OO++

Find:1. Electron

Transport Chain

2. Fermentation3. Formation of

acetyl CoA4. Glycolysis5. Kreb’s Cycle

C

Cell Membrane

• Explain, in your own words, the next two slides.

C C C C C Cglucoseglucose NADNAD++ NADHNADH

C C Cpyruvatpyruvat

ee22

ADPADP ATPATP22 22

22 22

22lactatelactateNADHNADH NAD+NAD+

C C C

C C22ethanethan

olol++ 22COCO22

NADHNADH

NADNAD++

C C Cpyruvatpyruvat

ee

CoACoA

acetyl acetyl CoACoAC C

COCO22

C C Cpyruvatpyruvat

ee

acetyl acetyl CoACoAC C

Krebs

cycle

ATPATP

ADPADP

NADNAD++

NADHNADHFADFAD

FADHFADH22

33

33

NADHNADH NAD+NAD+

e-

H+

H+

H+

H+

H+H+H+ H+H+

H+

½ O22

H+

HO2

H+

FADHFADH22 FADFAD

ATAT

PP

ADAD

PP

Glucose + O2 CO2 + H20 + Energy

2 CO2 CO22

CoACoA

NADHNADH

HH22OO++

C C C C C Cglucoseglucose NADNAD++ NADHNADH

C C Cpyruvatpyruvat

ee22 22lactatelactate

ADPADP ATPATP22 22

22 22 NADHNADH NAD+NAD+

C C C

C C22ethanoethano

ll++ 22COCO22

NADHNADH

NADNAD++

CoACoA

acetyl acetyl CoACoAC C

COCO22

Krebs

cycle

ATPATP

ADPADP

NADNAD++

NADHNADHFADFAD

FADHFADH22

33

33

NADHNADH NAD+NAD+

e-

H+

H+

H+

H+

H+H+H+ H+H+

H+

½ O22

H+

HO2

H+

2 x

FADHFADH22 FADFAD

ATAT

PP

ADAD

PP

CYTOSOLCYTOSOL

(matrix(matrix))

2 CO2 CO22

CoACoA

NADHNADH

HH22OO++

Cell membrane