Evolutionary Microbiology

Jong-Soon Choi

University of Science and Technology

- Contents -

1. Definition of Life

2. Origin of Life

3. Prion, Mad Protein

4. Virus, Dust of Life

5. Norovirus & Zoonosis

6. Bacteria, Planet Conqueror

7. Archaea, Extremity Survivor

8. Cyanobacteria, Oxygen Maker

9. Harmful Algal Bloom

10. Mitochondria, Perfectly Tamed

11. Multicellular Eucaryotes, Toward Complexity

12. Human, Apex of All Life1

Blue PlanetAre we ALONE?

미생에서 생명으로

천둥 몇 개, 벼락 몇 개, 밀물과 썰물 몇 번그 속에서 물 찌꺼기가 만들어진다아직은 미생이지만 그렇게 생명의 씨앗이 잉태된다

생명의 씨앗 RNA는 꿈을 꾼다RNA가 기억하는 꿈은 촉매와 유전이다그 기억은 위대한 생명의 방정식을 만든다

생명은 새로운 도전의 길로 나간다청빈한 구도자에서 게걸스런 탐욕자로 변신하다자신을 속박했던 껍질을 버리고 자유를 느낀다

생명은 점점 이기심으로 변해간다가끔씩 연민과 공감의 이타심을 보인다자유로운 영혼의 소유자는 그 다음 어디로 가는가?

From Not-yet Life To LifeWater scum is created thereWith a few thunder, lightning and web-and-tideStill not-yet life, but pregnant in a life seed

A life seed dreamed RNARNA’s dream memorized is catalysis and evolutionThat memory forms a great life equation

Life is now forwarding to a challenging roadTransformed from a truth-seeker to a greedy predator Escaped from the cover and felt freedom

Life is gradually changing to selfish existenceSometimes showed up its sympathy and altruismAlas! Where are the soul holder going next?

(Source: news.ku.dk) 2

Evolutionary Microbiology

Chapter 1. Definition of Life

Jong-Soon Choi

Chungnam National Univ. GRAST

University of Science and Technology

Korea Basic Science Institute

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Diversity of LIFE on Blue Planet

(Source: sites.google.com) 4

Definition of LIFE

WHAT IS LIFE?

ReproductionWhat is Reproduction? Life without reproduction?

MetabolismWhat is Metabolism? Life without metabolism?

AdaptationWhat is Adaptation? Adaptation-failed life?

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Properties of LIFE : Reproduction

Asexual vs. Sexual Reproduction

(Source: www.diffen.com)

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Cockroach Love

Dragonfly LoveShark Love

Praying Mantis Love

Human Love

WHAT and WHY Sexual Reproduction?

(Source: www.conserveca.com)

(Source: www.google.com)

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Sexual Bacterial Reproduction

Conjugation: direct transfer of genetic material between two joined bacterial cells

One way DNA transfer:- Male “donor”- Female “recipient”

Mechanism- Donor extends sex pili to recipient- Sex pilus retracts, pulling each

together- DNA transferred through

cytoplasmic bridge(Source: www.google.com)

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Life With/Without Reproduction

- The Origin of Life : Abiogenesis- Last Universal Common Ancestor (LUCA) 3.5BY- Synthetic Life : poliovirus, mycobacterium

Science 2002Chemical Formula of Poliovirus : C332652H492388N98245O131196P7501S2340

Science 2008Mycobacterium genitaliumA bacterium with the smallestgenome485 protein-coding genes100 genes, non-essential

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Hybrid Animal Without Reproduction

Mules cannot reproduce due to chromosome non-compatibility.

Infertile Big Cats

(Source: www.google.com) 10

Perfect Linkage between photosynthesis and respiration

Recycling Biotransformation

Properties of LIFE : Metabolism

Photosynthesis6CO2+6H2O+EninC6H12O6+6O2

Aerobic RespirationC6H12O6+6O2 6CO2+6H2O+Enout

(Source: Wikipedia) 11

Continual regeneration (Ruldolf Schoenheimer, 1935)Dynamic state of body constituents

MetabolicNetwork

Metabolism:Degradation(Catabolism)

+Biosynthesis(Anabolism)

WHYMetabolism

there?

Metabolism : Definition & Significance

(Source: Wikipedia) 12

Change of energy state by enzyme

HOW metabolism occurs?

Enzyme-mediatedbiotransformation

WHAT is Enzyme?Biologically highly selective catalysts

Origin of Enzyme?Ribozyme (catalytic

RNA) functions within ribosome to link AA

during protein synthesis, RNA

processing reaction, RNA splicing, etc.

Energ

y Sta

te

Reaction time

Barrier Energy

Enzyme

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Adenosine Triphosphate =1. Coenzyme2. Molecular Unit of Intracellular

Energy Transfer3. Substrate in Signal Transduction

250 gram ATP in human body

ATP = MolecularCurrency

NADH + cyt cox

+ ADP + Pi

NAD+ + cyt cred

+ ATP

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WHY ATP is chosen?WHY NOT GTP?

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Chemical Form Monomer PolymerPolymer Example

Amino acid

C H O N S (Se)

Amino acid Polypeptide

Fibrous proteinGlobular protein

Carbohydrate

C H O

Monosaccharide PolysaccharideStarch,

Glycogen, Cellulose

Nucleic acid

C H O N P

Nucleotide Polynucleotide

DNA, RNA

METABOLISM: Major Biomolecules and Bio-polymers

peptide bond

, -glycosidicbond

phosphodiesterbond 15

>10M organic

C-ompund

WHY carbon?

Cellulose

Nucleic acid (DNA, RNA)

Phospholipid

Protein (Source: www.google.com) 16

Carbon-based biomaterials Carbon chauvinism* Silicon-based microchip Silicon chauvinism

Constituent Atoms of LIFE : Carbon-centric

(Source: www.google.com)

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LIFE Chemistry : Water-based Chemical Reaction

Life Materials

1. Water (H2O)2. Life Elements: C,

H, O, N, P, S3. Life Polymers:

amino acid, carbohydrate, lipid, nucleic acid

Biochemical Function of Water

1. Solvent(용매): melting salt and polar molecules2. Transport(수송): H-bonding, materials transport3. Reagent(반응물): chemical reaction (hydrolysis)4. Insulator(절연): maximal density under freezing

point5. Coolant(냉각제): high heat-absorbing capacity

(Source: Wikipedia) 18

Properties of LIFE : Adaptation

- Adaptation = Adaptive trait, Natural Selection- Sexual Selection, Diversity

- Adaptedness (phenotype) vs. Fitness (genotype)

- Driving Force of Adaptation? Mutation

Peacock’s tail is the product of natural selection?

(Source: www.google.com) 19

Properties of LIFE : Adaptation

Evolution? Continuous improvement of a fitness of a species

Fitness Process by Replication, Mutation & Selection

(Source: www.google.com) 20

Physical Property of Life (Erwin Schroedinger)

HOW is LIFE explained by physicists’ language?

WHY are the atoms so small? =

WHY must our bodies be so large compared with the atom?

“Root N Rule”

Degree of inaccuracy (DI) =

√n/N

If N=100,

DI=√100/100=10%

If N=1,000,000

DI= √106/106=0.1%

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Shroedinger’s “What is Life?”

HOW Physicist and Chemist understand Life?Order-from-order principle (2nd Law of Thermodynamics)

Non-random state(low entropy)

Random state(high entropy)

LifeNon-Life

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Big Guy’s View about LIFE

Crick on Life

“…the origin of life appears at the momentto be almost a miracle, so many are the conditions which would have had to have been satisfied to get it going.”

Life Itself: Its Origin and Nature,Page 88Francis Crick, 1981

(Source: www.whatislife.ie/Cambridge.html)

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