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ORIGIN OF LIFE:

Early conditions on earth
-very beginning, too hot to sustain oceans
-primitive atmosphere
-reducing (electron adding)
-earth cools and condense to oceans
ORIGIN OF LIFE:

Conditions that made origin of life possible:
  1. abiotic systhesis of small organic molecules (aa &NT)
  2. joining of small molecules into polymers (prot/nucleic acids)
  3. packaging of these molecules into "protobionts"- droplets with membranes that maintain internal chem different from environment
  4. origin of self replicating molecules (inheritance)
ORIGIN OF LIFE:

Organic synthesis
Miller-Urey experiment
-demonstrate early atm made organic cmpds

-tested oparin hyp (early atm is reducing, organic cmpds form from lightning and UV rad) "primitive soup"

- warmed water "sea"
-reducing atm, h2, CH4, NH3
-sparks to mimic lightning
-condenser cooled and rained cmpds

*found that organic molecules can form in a strongly reducing (electron adding) atmosphere
ORIGIN OF LIFE:

Formation of primitive cells
-coacervate droplet molecules that are surrounded by water
-unstable
-protobionts- aggregates of abiotically produced molecules surrounded by a membrane or membrane like structure
ORIGIN OF LIFE:

Protobionts
- simple reproduction and metabolism
- maintain internal chemical environment
ORIGIN OF LIFE:

Liposomes
- form when lipids or organic molecules added to water to form bilayer that is selectively permeable
- osmotic reaction
- store NRG voltage across surface
- incorporate polymers form environment
ORIGIN OF LIFE:

First genetic information?
- probably RNA
- first was short and virus-like
ORIGIN OF LIFE:

Ribozymes
- RNA catalysts
- splicing, adding
- genotype, phenotype
- molecules with best sequences would replicate more often
ORIGIN OF LIFE:

No oxygen in early environment, so the organisms were... then it metabolized... and the atm gained ... which lead to organisms that were
- anaerobic
- co2
- oxygen
- aerobic
ORIGIN OF LIFE:

Development of early autotrophs
- evolved from protobionts
- anaerobic respiration
- fixed co2 to make o2 --> aerobic
ORIGIN OF LIFE:

Atmosphere changes from reducing to oxidizing
- from anaerobes
ENZYMOLOGY:

exergonic rxn:
endergonic rxn:
-exergonic releases NRG
-endergonic requires NRG
ENZYMOLOGY:

Catalyst
- speed up rxn by lowering activation energy by having a conformation that is favored
ENZYMOLOGY:


Enzymes
- lower activation energy of a rxn
- increase the rate of the rxn
- do not affect the overall change in G of the rxn
- aer not changed or consumed in the course of the rxn
ENZYMOLOGY: 


Helper molecules
-cofactor
-coenzyme
-cofactor- inorganic, prothetic if covalently bonded
- coenzyme- organic
ENZYMOLOGY:

Competitive inhibition
- molecules mimic substrate and block enzyme active site
ENZYMOLOGY:

Allosteric
- other sites on the enzyme
- stimulate or inhibit enzyme activity
ENZYMOLOGY:

Enzyme regulation-
Feedback inhibition
- products act as inhibitor
- low amts of products activate pathway
ENZYMOLOGY:

Allosteric regulation
- varying concentrations of allosteric inhibitors and activator can determine the rate and duration of enzyme activity
ENZYMOLOGY:

Defn: metabolism
- totality of organism's chemical rxns
ENZYMOLOGY:

Defn: metabolic pathway
- series in which molecule is altered in steps
ENZYMOLOGY:

Catabolism
Anabolism
-Catabolic- break down
-anabolic- build up
ENZYMOLOGY:

Lock & key theory
- spatial structure of active site is exactly complementary to spatial structure of substrate (discontinued)
ENZYMOLOGY: 

induced fit theory
- active site is flexible
- when substrate enters, active site conforms to change
ENZYMOLOGY:

What is a substrate
- reactant an enzymes bind to
ENZYMOLOGY:

rxns with 2+ reactants
  1. active site provides template for substrate to come together in proper orentation for rxn to occur
  2. clutches substrate and may stretch the molecule toward their transition state conformation
  3. active site provides better environment for rxn without enzyme
  4. direct participation (covalent bonding)
ENZYMOLOGY: 

What does it mean when a rxn is saturated?
- all active sites in used, must add more enzymes to increase rxn
ENZYMOLOGY:

Factors affecting enzymes
-temperature- temp increases=rate of enzyme increased until it reaches optimal temp, becomes denatured
optimal temp is 35-40C in humans

-pH- enzyme specific
-humans usually 7.2
optimal=environmental PH
works at optimal, then denatures if outside

-concentrations
increase concentration= increase in rate until all active sites are occupied
ENZYMOLOGY: 

Enzyme reversibility
- product synthesized by enzyme can be decomposed by same enzyme
ENZYMOLOGY: 

Michaelis-Menten
ENZYMOLOGY:

Enzyme activity- hydrolysis
-breaks a water molecules to break large molecules
ENZYMOLOGY:

Enzyme activity- dehydration/ condensation
- water is expelled to synthesized molecules
CELLULAR METABOLISM:

chemical pathways transfer energy
anabolic- require energy, assemble larger molecule

catabolic- release energy, breaking down large molecules
CELLULAR METABOLISM:

What is respiration?
- conversion of chemical energy in bonds to usable energy
CELLULAR METABOLISM:
 
C-H bond energy rich
carbs/fats favored by cell
dehydrogenaion
NRG used to form NRG phosphate bond in ATP
GLYCOLYSIS:

Where does it occur?
What does it create?
Stages?
- occurs in cytoplasm
- creates 2 molecules of pyruvate from 1 molecule glucose
- NRG investment stage/ NRG payoff stage
GLYCOLYSIS:

PGAL
GLYCOLYSIS:

Substrate level physphorylation
ATP synthesis is directly coupled with degradation of glucose without an intermediate
Glycolysis steps
GLYCOLYSIS:

net rxn?
GLUCOSE + 2ADP + 2Pi + 2NAD+ --> 2 pyruvate + 2ATP + 2 NADH + 2H+ + 2H20
GLYCOLYSIS:

Under anaerobic conditions ___ is needed for glycolysis
NAD+
GLYCOLYSIS:

Lactic acid fermentation
GLYCOLYSIS:

Alcohol Fermentation
GLYCOLYSIS:

Oxygen is present
Goes to kreb cycle
- 2 pyruvate is actively tranported to mitochondrial matric to be decarboxylated
-acetyl added to CoA and NAD+ --> NADH
KREB'S CYCLE:

Net rxn:
KREB's CYCLE:

Steps
KREB's CYCLe

-2 turns
2 x 3 NADH
2 x 1 FADH
2 x 1 GTP (ATP)

1 glucose= 2 pyruvate
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