Lesson 8: BACTERIAL METABOLISM Flashcards
harness the suns light to make food and generate energy without using oxygen.
Cyanobacteria
The formation or breakdown of chemical bonds is made possible by collision of atoms, ions or molecules that are continuously moving and colliding with one another called
Collision Theory
the sum of all chemical reactions within a living organism. It is divided into two types of chemical reactions: the catabolic reaction and the anabolic reaction
Metabolism
an enzyme-regulated chemical process that releases energy whereby complex organic compounds are breakdown into simpler ones. This reaction mainly uses water (hydrolytic reaction) to break chemical bonds, and produce more energy that they consume (exergonic).
Catabolism
an enzyme-regulated chemical process that requires energy to build complex organic molecules from simpler ones. This reaction mainly releases water (dehydration synthesis reaction), and consume more energy that they produce
Anabolism
provide the building blocks for anabolic reactions and also supply the energy needed for it in the form ATP.
Catabolic reactions
The energy required for a chemical reaction is called
Activation Theory
They are substances which serve as biological catalysts that speed up chemical reactions without them being permanently altered.
Enzymes
Each enzyme has a unique surface configuration that enables it to bind to its corresponding substance called
Substrate
The bind of Enzymes unique surface configuration to substrate
The lock and key model
results to a more effective collision of molecules and thus reduces the activation energy required for a reaction
Effective Enzyme-substrate complex
The mechanism of enzymatic actions are
- The surface of the substrate contacts a specific region of the surface of the enzyme molecule called the active site.
- A temporary intermediate compounds forms, called an enzyme-substrate complex. 3. The substrate molecule is transformed either by rearrangement, breakdown or in combination with other molecule.
- The transformed substrate molecules are released from the enzyme molecule.
- The unchanged enzyme is now free to react with other substrate molecules.
Some of the factors that influence enzymatic activity are
Temperature
pH
substrate
inhibitors
as it increases the rate of chemical reactions also increases. However, once the optimal is reached, chemical reaction is reduced following the denaturation (change in structure) of enzyme.
Temperature
the reaction also decline once optimal is reached.
pH
Inhibits enzymatic
action; can either be competitive or non-competitive
Inhibitor
compete with normal substrate for the active site
Competitive Inhibitor
interact with another part of the enzyme
non-competitive inhibitor
inhibitors bind to parts of the enzyme other than substrate binding site. This binding will change the shape of the enzyme making it inactive thus stops the cell to produce more substance than it
allosteric or feedback inhibition
The process by which non-competitive inhibitors carry out its function is called
allosteric or feedback inhibition
are a type of RNA that serving as catalyst acting specifically on strands of RNA
Ribozymes
two general aspects of energy production
The concept of oxidation-reduction and the mechanisms of ATP generation.
Oxidation is the removal of electron from an atom or molecule in a reaction
that produces energy. Reduction is gaining one or more electron. These
two reactions are always coupled, each time a molecule is oxidized
another is simultaneously reduced.
Oxidation Reduction (Redox) Reactions
Three mechanisms Phosphorylation
- Substrate-level phosphorylation
- Oxidative phosphorylation
- Photophosphorylation
used by cells in catabolism to extract energy from nutrient molecules. For example: oxidation of glucose (C6H12O6) to CO2 and H2O will release energy that will be trapped by ATP which can then serve as energy source.
Oxidation – Reduction (Redox) Reaction
The generation of ATP
The energy released during redox reaction is trapped by ATP within the cell as energy reserve by addition of a phosphate group to ADP in a process called phosphorylation
ATP is generated when a high energy P is directly transferred from phosphorylated compound to ADP
Substrate-level phosphorylation
electrons are transferred from organic compound to a series of electron carriers in a system called electron
transport chain. During transfer of electron from one carrier to another releases energy which then binds to ADP to generate ATP
Oxidative phosphorylation
most common carbohydrate energy source used by cells.
Glucose
occurs only in photosynthetic cells which contain chlorophyll (light energy trapping pigments) that can be converted into ATP in a process involving electron transport chain system
Photophosphorylation
the primary source of cellular energy in most microorganisms.
Oxidation of carbohydrates
splitting of sugar
Glycolysis
Energy production from glucose use two processes
cellular respiration and fermentation, both process starts
oxidation of glucose into pyruvic acid that
occurs during the first stage of carbohydrate catabolism.
Glycolysis
Glycolysis can also be called
Embden- Meyerhof pathway
Other bacteria have alternative pathways of oxidizing glucose like
Pentose phosphate pathway or Entner-Doudoroff pathway
Bacteria that uses Pentose Phosphate Pathway
B. subtilis
E. coli
Enterococcus faecalis
Bacteria that uses Entner-Doudoroff pathway
Pseudomonas
Agrobacterium
Two processes of energy production from glucose
Cellular respiration and fermentation
an ATP-generating process wherein the final electron acceptor is an inorganic molecule.
Cellular respiration
done in a process called Krebs cycle also called as tricarboxylic cycle or citric acid cycle. Krebs cycle releases ATP from acetyl coA in its every step. Acetyl coA is the resulting complex of acetyl group (derived from pyruvic acid) and coenzyme A.
Aerobic respiration
two kinds of cellular respiration
Aerobic respiration and anaerobic respiration
Kreb Cycle can also be called as
tricarboxylic cycle or citric acid cycle
the final electron acceptor is an inorganic molecule other than oxygen
Anaerobic respiration
Examples od Anaerobic respiration
Pseudomonas and Bacillus
using nitrate ion
Desulfovibrio using sulfate.
enerate energy from sugars and other organic molecules such as amino acids, organic acids, purines and pyrimidines by not requiring oxygen, Krebs cycle or electron transport chain system. Uses an organic molecule as the final electron acceptor but produces only small amounts of ATP.
Fermentation
Examples of fermentaions
lactic acid fermentation and Alcohol Fermentation
end-product is lactic acid
Lactic acid fermentation
end-product is ethanol
Alcohol fermentation
Bacteria that uses alcohol fermentation
Saccharomyces
Bacteria that use lactic acid fermentation
Lactobacillus
Streptococcus
Aside from glucose, microbes also oxidize
lipids and proteins
Enzymes that breaks down lipids
Lipases
broken down by extracellular enzymes called lipases before it undergoes
oxidation in Kreb’s cycle.
The fatty acids and glycerol in lipids
broken into amino acids by enzymes proteases and peptidases before they can pass thru the plasma membranes. The amino acids then undergo deamination (removal of amino group) before it enters the Krebs cycle.
Proteins
Enzymes that breaks down proteins
proteases and peptidases
Removal of amino acids
deamination
a process from which microorganisms can obtain energy from inorganic substance by converting sunlight energy into chemical energy. The chemical energy produced will then convert carbon dioxide in atmosphere to sugars in a process called carbon fixation
Photosynthesis
a life mechanism on earth to
recycle carbon dioxide excreted by other organisms (ex: human) to be used by plants and other microorganisms.
Carbon Fixation
Two stages of photosynthesis
Light-dependent (light) reactions and;
light independent (dark) reactions
uses light energy to generate energy
(photophosphorylation)
Light-dependent (light) reactions
breakdown of carbon dioxide into sugar using energy generated in the first stage (Calvin-Benson cycle)
light independent (dark) reactions
Metabolic pathways that uses the energy generated
- Polysaccharide biosynthesis
- Lipid biosynthesis
- Amino acid and protein biosynthesis
- Purine and pyrimidine biosynthesis
