LESSON 8 : BACTERIAL METABOLISM Flashcards
Is the sum of all chemical reactions within a living organism.
Metabolism
METABOLISM
it is divided into two types of chemical reactions:
catabolic reaction and anabolic reaction
is an enzyme-regulated chemical process that releases energy whereby complex organic compounds are breakdown
into simpler ones.
catabolic reaction
This reaction mainly uses water (hydrolytic reaction) to break chemical bonds, and produce more energy that they consume (exergonic)
is an enzyme-regulated chemical process that
requires energy to build complex organic molecules from simpler ones.
anabolic reaction
This reaction mainly releases water (dehydration synthesis reaction), and consume more energy that they produce (endergonic
Catabolic reactions provide the building blocks for anabolic reactions and also
supply the energy needed for it in the form of adenosine triphosphate (ATP)
adenosine triphosphate (ATP)
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 also called
“collision theory”
The energy required for a chemical reaction is called
Activation energy
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.
Substrate
This is called “lock and key model”.
Substrate
factors that influence enzymatic activity are :
- Temperature
- Ph
- Substance
- Inhibitors
(1) temperature:
as temperature increases the rate of chemical reactions also increases. However, once the optimal temperature is reached, chemical reaction is reduced following the
denaturation (change in structure) of enzyme.
(2) pH: the reaction also decline once
optimal pH is reached.
(3) substrate concentration,
(4) inhibitors: inhibits enzymatic
action; can either be competitive [compete with normal substrate for the active site]
or non-competitive inhibitor [interact with another part of the enzyme].
The process
by which non-competitive inhibitors carry out its function is called –
inhibition wherein inhibitors bind to parts of the enzyme other than
substrate binding site.
allosteric or
feedback
are a type of RNA that serving as catalyst acting specifically on
strands of RNA during protein synthesis. ENERGY
Ribozymes
ENERGY PRODUCTON
Two general aspects of energy production :
Concept of oxidation-reduction
2. generation of ATP
is the removal of electron from an atom or molecule in a reaction
that produces energy.
Oxidation
is gaining one or more electron
Reduction
These
two reactions are always coupled, each time a molecule is oxidized
another is simultaneously reduced.
Oxidation-reduction
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
Three mechanisms of phosphorylation
- Substrate-level phosphorylation
- Oxidative phosphorylation
- Photophosphorylation
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
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 most common carbohydrate energy source used by cells.
Glucose
is the primary source of cellular energy in most
microorganisms.
Oxidation od carbohydrates
Energy production from glucose use two processes
- Cellular respiration
- Fermentation
is oxidation of glucose into pyruvic acid that occurs during the first stage of carbohydrate catabolism
Glycolysis
Glycolysis it is also called
Embden-Meyerhof pathway
Two processes of energy production from glucose:
an ATP-generating process wherein the final electron acceptor
is an inorganic molecule.
Cellular Resporation
2 types of cellular respiration
- Aerobic respiration
- Anaerobic respiration
is done in a process called Krebs cycle also
called as tricarboxylic cycle or citric acid cycle.
Aerobic respiration
is the resulting
complex of acetyl group (derived from pyruvic acid) and coenzyme
A.
Acetyl coA
the final electron acceptor is an inorganic
molecule other than oxygen.
Anaerobic respiration
generate 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
Fermentation
Examples of fermentation:
1. Lactic acid fermentation: end-product is lactic acid (Lactobacillus, Streptococcus)
- Alcohol fermentation: end-product is ethanol (Saccharomyces)
process from which microorganisms can obtain energy from
inorganic substance by converting sunlight energy into chemical energy
Photosynthesis
The chemical energy produced will then convert carbon dioxide in atmosphere to sugars in a process called
Carbon fixation
Two stages of photosynthesis:
- Light-dependent
- Light-Independent
uses light energy to generate energy
(photophosphorylation)
Light- dependent (light) Rection
Breakdown of carbon dioxide into
sugar using energy generated in the first stage (Calvin-Benson cycle)
Light-Independent (dark) reaction
Metabolic pathways that uses the energy generated by processes presented
above
- Polysaccharide biosynthesis
- Lipid biosynthesis
- Amino acid and protein biosynthesis
- Purine and pyrimidine biosynthesis
