Chapter 6 Microbial Metabolism: Fueling Cell Growth // Nester's Microbiology

all cells need to accomplish 2 fundamental tasks:

synthesize new parts and harvest energy to power reactions

the total sum of synthesizing new parts and harvesting energy is called...

metabolism

metabolism can be separated into 2 parts:

anabolism and catabolism

catabolism

processes that degrade compounds to release energy that cells then capture to make ATP

anabolism

assembly of subunits of macromolecules, ATP is used to drive reactions

ATP minus a phosphate is

catabolism

ADP plus a phosphate is

anabolism

photosynthetic orgs harvest energy from sun and use it to

power the synthesis of organic compounds from CO2

chemoorganotrophs obtain energy from organic compounds and depend on

the activities of photosynth orgs

free energy

energy avail to do work

exergonic reactions

reactants have more free energy - energy is release in reaction

endergonic reactions

products have more free energy - reaction requires input of energy

metabolic pathways

series of chemical reactions that convert starting compound to end product

metabolic pathways types/"shapes" (3)

branched, linear, cyclical

what are enzymes

biological catalysts that accelerate conversion of substrate into product by lowering activation energy

3 processes that generate ATP

substrate level phosphorylation, oxidative phosphorylation, photophosphorylation

substrate-level phosphorylation is powered by

exergonic reaction

oxidative phosphorylation is powered by

proton motive force

photophosphorylation is powered by

sunlight created proton motive force

energy is released when electrons move from low affinity molecule to high affinity molecule, and more energy is release when...

difference in electronegativity is greater

know electron donor = energy source, acceptor = terminal electron acceptor

...

organic and inorganic compounds are used as what? O2 and other molecules are used as what?

energy source, electron acceptor

precursor metabolites

intermediates of catabolism that can be used in anabolism

3 central metabolic pathways in catabolism

glycolysis, pentose phosphate, tricarboxylic acid (TCA, Krebs)

point of metabolic pathways

ATP, reducing power, precursor metabolites

glycolysis start and outcomes (4)

splits glucose into 2 pyruvates, 2 ATP, reducing power (2 NADH and 2 H+), 6 precursors

pentose phosphate produces (2)

2 precursor metabolites and NADPH

Krebs cycle start and outcomes (3)

oxidizes pyruvates from glycolysis, generates reducing power 6 NADH and y H+, 2 precursors, 2 ATP, 2 FADH2

respiration and fermentation are also part of catabolism

...

respiration

transfers electrons from glucose to electron transport chain

aerobic resp

O2 is terminal electron acceptor

anaerobic resp

molecule other than O2 as terminal electron acceptor

what happens when cells can not respire (3)

they run out of caries available to accept electrons and glycolysis stops, forced into fermentation

fermentation

uses pyruvate or derivative as terminal electron acceptor to regenerate NAD+

where do substrates bind to enzymes?

at active site

what are cofctors

they assist enzymes in substrate binding

what are coenzymes

organic cofactors that function as loosely bound carriers of molecules or electrons

what does a 10C increase do to speed of enzymatic reaction up until max

doubles speed

Allosteric regulation

Enzyme activity controlled by binding to allsteric site

How does Allosteric regulation effect the enzyme

Shape is distorted, prevents or enhances binding

Type of enzyme inhibition is determines by what?

Which site the inhibitor binds to

Where does competitive inhibitor bind to

Active site

Competitive inhibitor is chemically similar to substrate?

Yes

Noncompetitive inhibitor by regulatory molecules does what to enzyme

Changes shape so substrate cannot bind to active site

Noncomp inhibitor by enzyme poisons does what to enzyme

Permanently changed shape, no longer function

In prok where is the electron transport chain located

Cytoplasmic membrane

In euk where is e- transport chain

Inner mitochondrial membrane

What is the e transport chain

Membrane embedded electron carrier that lets electrons pass though and ejects protons at same time = electrochemical gradient

3 groups of carriers

Quinones, cytochromes, flavoproteins

T or F: microbes can use variety of compounds for catabolism other than glucose

True

What other compounds? 4

Poly and di-saccharides, lipids, proteins

In photosynthesis there are 2 kinds of reactions/stages

Light in/dependent

Light dependent

Capture energy and convert to ATP

Light independent

Use ATP to synth organic compounds