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INDUSTRIAL
BIOTECHNOLOGY
BASICS
History of Biotechnology
What is Biotechnology?
Biotechnology is a field of applied biology that involves the use of living organisms and
bioprocesses in engineering, technolgy, medicine and other fields requiring bioproducts.
Modern use similar term includes genetic engineering as well as cell- and tissue culture
t h l i
technologies.
BIOLOGY
BioBio
chemist
ry
Bioengineering
CHEMISTRY
Chemistryg
g
engineering
ENGINEERING
Classification of Biotechnology
Red Biotechnology
Green Biotechnology
is applied to medical processes.
is biotechnology applied to
agricultural processes.
Some examples are the designing of
organisms to produce antibiotics, and
the engineering of genetic cures
through genetic manipulation
Domestication of plants via
micropropagation
micropropagation.
Drug production
Is the designing of transgenic plants
to grow under specific
environments in the presence (or
absence) of chemicals.
Pharmagenomics
Gene therapy
One hope is that green biotechnology
might produce more
environmentally friendly solutions
than traditional industrial
agriculture.
i l
Classification of Biotechnology
White Biotechnology
Blue Biotechnology
also known as industrial biotechnology, is
biotechnology applied to industrial
processes.
is a term that has been used to describe
the marine and aquatic applications of
biotechnology, but its use is relatively
rare.
Designing of an organism to produce a
useful chemical.
Using of enzymes as industrial catalysts
to either produce valuable chemicals or
destroy hazardous/polluting chemicals.
Biotechnology vs. chemical processes
Advandages of a biotechnological process
- Using of highly active, specific and selective enzyme
- Reduction
R d i off pollution
ll i
- Gentle process conditions (p,T, c)
- ATP as energy source
- Using
U i off cheap
h
raw materials
t i l ((waste
t products)
d t )
-Biocompatibility of the products
Disadvantage of a biotechnological Process
-Low efficiency (accumulated needs in process development)
- Low
L
concentrations
t ti
off th
the products
d t
-Genetic instability of the biocatalysts or MO-strains
-Process stability
- High Investments for plants and education
- High complexity and sensitivity of the processes
- Low acceptance in the population
Applications
1. Single Cell Proteins (SCP)
2. Metabolic products
•
•
•
•
•
3. Productivity
•
•
•
•
•
Bioconversion
Wastewater treatment
Waste air treatment
C
Composting
ti
Metal production
Alcohols
Al
h l
Citric acid, Lactic acid
Amino acids
Vitamins
Nucleotids
4. Active pharmaceutical
ingredients
• Erythopoetin
• Insulin
Nucleic acid - structure and organization
Deoxyribonucleic acid (DNA) is a nucleic acid
that contains the genetic instructions used in
the development and functioning of all known
living organisms with the exception of some
viruses.
DNA replication
replication, the basis for biological
inheritance, is a fundamental process occurring
in all living organisms to copy their DNA. This
process is „replication" in that each strand of
th original
the
i i l double-stranded
d bl t
d d DNA molecule
l
l
serves as template for the reproduction of the
complementary strand.
Transcription
T
i ti is
i the
th process off creating
ti
an
equivalent RNA copy of a sequence of DNA.
In translation, mRNA is decoded to produce a
specific polypeptide. This polypeptide has the
amino acid sequence specified by the DNA. The
polypeptide is either the whole protein, or a part
of it.
Chemical structure of DNA
DNA consists of two long polymers of simple units
called nucleotides, with backbones made of sugars
and phosphate groups joined by ester bonds
bonds. These
two strands run in opposite directions to each
other and are therefore anti-parallel. Attached to
each sugar is one of four types of molecules called
bases.
The backbone of the DNA strand is made from
alternating phosphate and sugar residues. The
sugar in DNA is 2-deoxyribose, which is a
pentose (five-carbon)
p
(
) sugar.
g The sugars
g
are jjoined
together by phosphate groups that form
phosphodiester bonds between the third and fifth
carbon atoms of adjacent sugar rings.
Th strands
The
t
d are antiparallel.
ti
ll l
Chemical structure of DNA
The asymmetric ends of DNA strands are called
the 5` (five prime) and 3` (three prime) ends, with
th 5' end
the
d having
h i a terminal
t
i l phosphate
h
h t group
and the 3' end a terminal hydroxyl group
The DNA double helix is stabilized by hydrogen
bonds between the bases attached to the two
strands.
The four bases found in DNA are adenine (A),
(A)
cytosine (C), guanine (G) and thymine (T).
These four bases are attached to the
sugar/phosphate to form the complete
nucleotide.
Chemical structure of DNA
RNA
Each nucleotide in RNA contains a ribose sugar, with
carbons numbered 1' through 5'. A base is attached to the
1' position, generally adenine (A), cytosine (C), guanine
(G) or uracile
il (U).
(U)
Messenger RNA (mRNA) carries information
about a protein sequence to the ribosomes
ribosomes, the
protein synthesis factories in the cell. It is codes so
that every three nucleotides (a codon) correspond
to one amino acid
acid.
Transfer RNA ((tRNA)) is a small RNA chain of
about 80 nucleotides that transfers a specific
amino acid to a growing polypeptide chain at the
ribosomal site of protein synthesis
y
during
g
translation.
It has sites for amino acid attachment and an
anticodon region for codon recognition that binds
to a specific sequence on the messenger RNA
chain through hydrogen bonding.
RNA-Functions
Ribosomal RNA
Ribosomal RNA (rRNA) is the catalytic component of the ribosomes.
Eukaryotic ribosomes contain four different rRNA molecules: 18S
18S, 5
5.8S,
8S 28S and
5S rRNA.
Three of the rRNA molecules are synthesized in the nucleolus,
nucleolus and one is
synthesized elsewhere .
Ribosome
Organization of the human Genome
The haploid human genome contains ca. 23,000 protein-coding genes, far
fewer than had been expected before its sequencing. In fact, only about 1.5% of
the genome codes for proteins
proteins, while the rest consists of non
non-coding
coding RNA genes
genes,
regulatory sequences, introns, and (controversially named) „junk „ DNA.
Surprisingly, the number of human genes seems to be less than a factor of two
greater than that of many much simpler organisms, such as the roundworm
and the fruit fly
fly.
Genome Sizes
Splicing
Splicing
However, human cells make extensive use of alternative splicing to produce
several different proteins from a single gene, and the human proteome is
thought to be much larger than those of the aforementioned organisms
organisms.
Biological function of proteins
A graphical representation of the normal human karyotype
DNA - packing of chromosoms
Schema of protein biosynthesis
DNA Replication
DNA replication, the basis for biological inheritance, is a fundamental process
occurring in all living organisms to copy their DNA
DNA.
This process is „replication" in that each strand of the original double-stranded
DNA molecule serves as template for the reproduction of the complementary
strand.
In a cell, DNA replication begins at specific locations in the genome, called
„origins". Unwinding of DNA at the origin, and synthesis of new strands, forms a
replication fork. In addition to DNA polymerase, the enzyme that synthesizes the
g nucleotides matched to the template
p
strand,, a number of
new DNA byy adding
other proteins are associated with the fork and assist in the initiation and
continuation of DNA synthesis.
Helicases are a class of enzymes vital to all living organisms. They are motor
proteins that move directionally along a nucleic acid phosphodiester backbone,
separating two annealed nucleic acid strands (i.e., DNA, RNA, or RNA-DNA
hybrid) using energy derived from ATP hydrolysis.
DNA-Replication
Transcription
During transcription, a DNA sequence is read by RNA polymerase, which
produces a complementary, antiparallel RNA strand.
As opposed to DNA replication, transcription results in an RNA complement
that includes uracil (U) in all instances where thymine (T) would have occurred
in a DNA complement.
complement
Transcription is the first step leading to gene expression.
If the g
gene transcribed encodes for a p
protein,, the result of transcription
p
is
messenger RNA (mRNA), which will then be used to create that protein via the
process of translation. Alternatively, the transcribed gene may encode for
either ribosomal RNA (rRNA) or transfer RNA (tRNA),
tRNA), other components of the
protein-assembly process, or other ribozmes.
Transcription
In eukaryotes, RNA polymerase, and therefore the initiation of transcription,
requires the presence of a core promotor sequence in the DNA.
Promoters are regions of DNA which promote transcription and in eukaryotes,
are found at -30,
-30 -75 and -90 base pairs upstream from the start site of
transcription.
Core promoters are sequences within the promoter which are essential for
transcription initiation. RNA polymerase is able to bind to core promoters in the
presence of various specific transkription factors.
The most common type of core promoter in eukaryotes is a short DNA
sequence known as a TATA box, found -30 base pairs from the start site of
transcription.
The TATA box, as a core promoter, is the binding site for a transcription
factor known as TATA binding protein (TBP), which is itself a subunit of
another transcription factor, called Transcription factor II D (TFIID).
Initiation-Elongation-Termination
Polymerase)
(RNAP RNA
Splicing
In molecular biology, splicing is a modification of an RNA after
transcription in which introns are removed and exons are joined
transcription,
joined.
This is needed for the typical eukaryotic messenger RNA before it can be used to
produce a correct protein through translation
translation.
For many eukaryotic introns, splicing is done in a series of reactions which are
catalyzed by the spliceosome, a complex of small nuclear ribonucleoproteins
(snRNPs), but there are also self-splicing introns.
Alternative Splicing
Splicing
Translation
Translation is the third stage of protein biosynthesis (part of the overall
process of gene expression). In translation, messenger RNA (mRNA)
produced by transcription is decoded by the ribosome to produce a
specific amino acid chain
chain, or poypeptide
poypeptide, that will later fold into an active
protein.
Translation occurs in the cell
cell's
s cytoplasma, where the large and small subunits of
the ribosome are located, and bind to the mRNA.
g by
y inducing
g the binding
g of tRNAs with
The ribosome facilitates decoding
complementary anticodon sequences to that of the mRNA.
The tRNAs carry specific amino acids that are chained together into a
polypeptide as the mRNA passes through and is "read" by the ribosome in
a fashion reminiscent to that of a stock ticker and ticker tape.
Translation
Protein functions
Antibodies - are specialized proteins involved in defending the body from
antigens (foreign invaders)
invaders). One way antibodies destroy antigens is by
immobilizing them so that they can be destroyed by white blood cells.
Contractile
C
il Proteins
P
i - are responsible
ibl ffor movement. E
Examples
l iinclude
l d actin
i
and myosin. These proteins are involved in muscle contraction and movement.
Enzymes - are proteins that facilitate biochemical reactions. They are often
referred to as catalysts because they speed up chemical reactions. Examples
include the enzymes lactase and pepsin. Lactase breaks down the sugar
lactose found in milk. Pepsin is a digestive enzyme that works in the stomach
to break down proteins in food.
Protein functions
Hormonal Proteins - are messenger proteins which help to coordinate certain
bodily activities
activities. Examples include insulin
insulin, oxytocin
oxytocin, and somatotropin
somatotropin. Insulin
regulates glucose metabolism by controlling the blood-sugar concentration.
Oxytocin stimulates contractions in females during childbirth. Somatotropin is a
growth hormone that stimulates protein production in muscle cells
cells.
Structural Proteins - are fibrous and stringy and provide support. Examples
include keratin, collagen, and elastin. Keratins strengthen protective coverings
such as hair, quills, feathers, horns, and beaks. Collagens and elastin provide
pp for connective tissues such as tendons and ligaments.
g
support
Storage Proteins - store amino acids. Examples include ovalbumin and casein.
Ovalbumin is found in egg whites and casein is a milk-based protein.
Protein functions
Transport Proteins - are carrier proteins which move molecules from one place
to another around the body
body. Examples include hemoglobin and cytochromes
cytochromes.
Hemoglobin transports oxygen through the blood. Cytochromes operate in the
electron transport chain as electron carrier proteins.
Amino acids
Amino acids
Abbreviation for Amino acids
Peptide bond
Protein amino acids are combined into a
single polypeptide chain in a condensation
reaction This reaction is catalysed by the
reaction.
ribosome in a process known as
translation.
The amino acids in a polymer are joined
together by the peptide bonds between
the carboxyl and amino groups of adjacent
amino acid resid
residues.
es
In general, the genetic code specifies 20
standard L- amino acids;; however,, in
certain organisms the genetic code can
include selenocysteine—and in certain
archaea-pyrrolysine.
Protein structures
Primary structure: the amino acid sequence.
Secondary structure: regularly repeating local structures stabilized by hydrogen
bonds. The most common examples are the alpha helix, beta sheet and turns.
Tertiary structure: the overall shape of a single protein molecule; the spatial
relationship of the secondary structures to one another
another. Tertiary structure is
generally stabilized by nonlocal interactions, most commonly the formation
of a hydrophopic core, but also through salt bridges, hydrogen bonds,
disulfide bonds, and even posttranslational modifications.
Quaternary structure: the structure formed by several protein molecules
(polypeptide chains),
chains) usually called protein subunits
subunits.
Protein structures
Protein modifications
After translation, the posttranslational modification of amino acids extends the
range of functions of the protein by attaching to it other biochemical functional
groups
g
p such as
acetate, phosphate, various lipids and carbohydrates,
by changing the chemical nature of an amino acid (e.g. citrullination) or by
making structural changes, like the formation of disulfide bridges.
Protein - Modifications
Der genetische Code
The genetic code is the set of rules by which information encoded in genetic
material (DNA ormRNA sequences) is translated into proteins (amino acid
sequences) by living cells.
The code defines a mapping between tri-nucleotide sequences, called
codons,, and amino acids.
With some exceptions, a triplet codon in a nucleic acid sequence specifies a
single amino acid.
acid
There are 4³
4 = 64 different codon combinations possible with a triplet codon
of three nucleotides; all 64 codons are assigned for either amino acids or stop
signals during translation.
Genetic code
The genetic code
Enzyms
Enzymes are proteins that catalyze (i.e., increase the rates of) chemical
reactions.
In enzymatic reactions, the molecules at the beginning of the process are called
substrates, and the enzyme converts them into different molecules, called the
products.
products
Almost all processes in a biological cell need enzymes to occur at significant
rates.
Since enzymes are selective for their substrates and speed up only a few
g many
yp
possibilities,, the set of enzymes
y
made in a cell
reactions from among
determines which metabolic pathways occur in that cell.
Like all catalysts, enzymes work by lowering the activation energy for a
reaction, thus dramatically increasing the rate of the reaction.
As a result, products are formed faster and reactions reach their equilibrium state
more rapidly. Most enzyme reaction rates are millions of times faster than those
of comparable un-catalyzed reactions.
Carbonic anhydrases reaction
Inhibition
Faktoren der Enzymaktivität
Competitive inhibition
In competitive inhibition, the inhibitor and substrate compete for the enzyme
(i e they can not bind at the same time)
(i.e.,
time). Often competitive inhibitors strongly
resemble the real substrate of the enzyme. For example, methotrexate is a
competitive inhibitor of the enzyme dihydrofolate reductase, which catalyzes the
reduction of dihydrofolate to tetrahydrofolat
tetrahydrofolat.
Note that binding of the inhibitor need not be to the substrate binding site (as
frequently stated), if binding of the inhibitor changes the conformation of the
enzyme to prevent substrate binding and vice versa.
p
inhibition the maximal velocity
y of the reaction is not changed,
g , but
In competitive
higher substrate concentrations are required to reach a given velocity, increasing
the apparent Km.
Kinetics
Uncompetitive inhibition and Non-competitive inhibition
Uncompetitive inhibition
In uncompetitive inhibition the inhibitor can not bind to the free enzyme,
enzyme
but only to the ES-complex. The EIS-complex thus formed is enzymatically
inactive. This type of inhibition is rare, but may occur in multimeric enzymes.
Non-competitive inhibition
Non competitive inhibitors can bind to the enzyme at the same time as the
Non-competitive
substrate, i.e. they never bind to the active site. Both the EI and EIS
complexes are enzymatically inactive.
Because the inhibitor can not be driven from the enzyme by higher substrate
concentration (in contrast to competitive inhibition), the apparent Vmax changes.
But because the substrate can still bind to the enzyme, the Km stays the same.
Enzyme classification
EC 1 Oxidoreductases: catalyze oxidation/reduction reactions
EC 2 T
Transferases:
f
t
transfer
f a functional
f
ti
l group (e.g.
(
a methyl
th l or
phosphate group)
EC 3 Hydrolases: catalyse the hydrolysis of various bonds
EC 4 Lyases:
y
cleave various bonds by
y means other than hydrolysis
y
y
and
oxidation
EC5 Isomerases: catalyze isomerization changes within a single
molecule
EC6 Ligases: join two molecules with covalent bonds
Industrial applications
Phylogenetic tree of life
Prokaryotic cell structure
Eukaryotic cell structure
Animal cell structure
Centrioles - Centrioles are self-replicating organelles made up of nine bundles of
microtubules and are found only in animal cells. They appear to help in
organizing cell division,
division but aren
aren'tt essential to the process.
process
Cilia and Flagella - For single-celled eukaryotes
eukaryotes, cilia and flagella are essential
for the locomotion of individual organisms. In multicellular organisms, cilia
function to move fluid or materials past an immobile cell as well as moving a cell
or group of cells.
Endoplasmic Reticulum - The endoplasmic reticulum is a network of sacs
that manufactures, processes, and transports chemical compounds for use
inside and outside of the cell. It is connected to the double-layered nuclear
envelope, providing a pipeline between the nucleus and the cytoplasm.
Animal cell structure
Endosomes and Endocytosis - Endosomes are membrane-bound vesicles,
formed via a complex family of processes collectively known as endocytosis,
and found in the cytoplasm of virtually every animal cell
cell. The basic mechanism of
endocytosis is the reverse of what occurs during exocytosis or cellular secretion.
It involves the invagination (folding inward) of a cell's plasma membrane to
surround macromolecules or other matter diffusing through the extracellular fluid
fluid.
Golgi Apparatus - The Golgi apparatus is the distribution and shipping
department for the cell's chemical products. It modifies proteins and fats built
in the endoplasmic
p
reticulum and p
prepares
p
them for export
p to the outside of the
cell.
Animal cell structure
Intermediate Filaments - Intermediate filaments are a very broad class of
fibrous proteins that play an important role as both structural and functional
elements of the cytoskeleton. Ranging in size from 8 to 12 nanometers,
intermediate filaments function as tension-bearing elements to help maintain cell
shape and rigidity.
Lysosomes - The main function of these microbodies is digestion.
Lysosomes break down cellular waste products and debris from outside the cell
into simple
p compounds,
p
, which are transferred to the cytoplasm
y p
as new cellbuilding materials.
Animal cell structure
Microfilaments - Microfilaments are solid rods made of globular proteins called
actin These filaments are primarily structural in function and are an
actin.
important component of the cytoskeleton.
Microtubules - These straight,
straight hollow cylinders are found throughout the
cytoplasm of all eukaryotic cells (prokaryotes don't have them) and carry out a
variety of functions, ranging from transport to structural support.
Mitochondria - Mitochondria are oblong shaped organelles that are found in the
cytoplasm of every eukaryotic cell. In the animal cell, they are the main power
generators,, converting
g
g oxygen
yg and nutrients into energy.
gy
Nucleus - The nucleus is a highly specialized organelle that serves as the
information p
processing
g and administrative center of the cell. This organelle
g
has
two major functions: it stores the cell's hereditary material, or DNA, and it
coordinates the cell's activities, which include growth, intermediary
metabolism, protein synthesis, and reproduction (cell division).
Animal cell structure
Peroxisomes - Microbodies are a diverse group of organelles that are found in
the cytoplasm, roughly spherical and bound by a single membrane. There are
several types of microbodies but peroxisomes are the most common
common.
Plasma Membrane - All living cells have a plasma membrane that encloses their
contents In prokaryotes,
contents.
prokaryotes the membrane is the inner layer of protection
surrounded by a rigid cell wall. Eukaryotic animal cells have only the membrane
to contain and protect their contents. These membranes also regulate the
passage of molecules in and out of the cells.
Ribosomes - All living cells contain ribosomes, tiny organelles composed of
pp
y 60 p
percent RNA and 40 p
percent p
protein. In eukaryotes,
y
, ribosomes
approximately
are made of four strands of RNA. In prokaryotes, they consist of three strands of
RNA
Gram positive/Gram negative
Plasmid
A plasmid is a DNA molecule that is separate from, and can replicate
independently of, the chromosomal DNA.
They are double stranded and, in many cases, circular. Plasmids usually
occur naturally in bacteria, but are sometimes found in eukaryotic
organisms (e
(e.g.,
g the 2-micrometre-ring in Saccharomyces cerevisiae)
cerevisiae).
Plasmid size varies from 1 to over 1,000kilobase pairs (kbp).
The number of identical plasmids within a single cell can range anywhere from
one to even thousands under some circumstances.
part of the mobilome,, since they
y are often
Plasmids can be considered to be p
associated with conjugation, a mechanism of horizontal gene transfer
Plasmids used in genetic engineering are called vectors. Plasmids serve as
important tools in genetics and biotechnology labs, where they are
commonly used to multiply (make many copies of) or express particular
genes.
Bacterial DNA and plasmids
Bacterial morphology
Bacterial growth curve
Bacterial growth
Bacterial growth in batch culture can be modeled with four different phases: lag
phase (A), exponential or log phase (B), stationary phase (C), and death
phase (D).
During lag phase, bacteria adapt themselves to growth conditions. It is the
period where the individual bacteria are maturing and not yet able to divide.
During the lag phase of the bacterial growth cycle, synthesis of RNA,
enzymes and other molecules occurs. So in this phase the microorganisms
are not dormant.
Bacterial growth
Exponential phase (sometimes called the log phase or the logarithmic
phase) is a period characterized by cell doubling. The number of new
bacteria appearing per unit time is proportional to the present population.
population If
growth is not limited, doubling will continue at a constant rate so both the
number of cells and the rate of population increase doubles with each
consecutive time period.
period
During stationary phase, the growth rate slows as a result of nutrient depletion
and accumulation of toxic products. This phase is reached as the bacteria
begin to exhaust the resources that are available to them. This phase is a
constant value as the rate of bacterial growth is equal to the rate of bacterial
death.
At death phase, bacteria run out of nutrients and die.
Autotroph
An autotroph, or producer, is an organism that produces complex
organiccompounds (such as carbohydrates, fats, and proteins) from simple
inorganic molecules using energy from light (by photosynthesis) or inorganic
chemical reactions (chemosynthesis).
They are the producers in a food chain, such as plants on land or algae in water.
They are able to make their own food and can fix carbon.
g
compounds
p
as an energy
gy source or a carbon
Therefore,, theyy do not use organic
source. Autotrophs can reduce carbon dioxide (add hydrogen to it) to make
organic compounds.
An autotroph converts physical energy from sun light (in case of green plants)
into chemical energy in the form of reduced carbon.
Autotroph
Autotrophs can be phototrophs or lithotrophs (chemoautotrophs).
Phototrophs use light as an energy source, while lithotrophs oxidize inorganic
compounds such as hydrogen sulfide
compounds,
sulfide, elemental sulfur
sulfur, ammonium and ferrous
iron.
Phototrophs and lithotrophs use a portion of the ATP produced during
photosynthesis or the oxidation of inorganic compounds to reduce NADP+ to
g
compounds.
p
NADPH in order to form organic
Heterotrophs
Heterotrophs, take in autotrophs as food to carry out functions necessary for their
life Thus
life.
Thus, heterotrophs — all animals
animals, almost all fungi
fungi, as well as most bacteria
and protozoa — depend on autotrophs for the energy and raw materials they
need.
Heterotrophs obtain energy by breaking down organic molecules (carbohydrates,
fats, and proteins) obtained in food.
Overview of cycle between autotrophs and
heterotrophs
Bacteria
Bacteria are a large domain of single-cell, prokaryote microorganisms. Typically
a few micrometers in length, bacteria have a wide range of shapes, ranging from
p
to rods and spirals
p
spheres
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes
g
such as yyeasts and molds,, as well as the more familiar
microorganisms
mushrooms.
Fungus
Cells
The range of sizes
Biotech-Products
Biotech-Products
Biotech Products
Catabolism
Catabolism is the metabolic reaction cells
undergo
g to extract energy.
gy There are two
major metabolic pathways of
monosaccharide catabolism: glycolysis and
the citric acid cycle.
Anabolic processes produce peptides,
proteins,
t i
polysaccharides,
l
h id
lilipids,
id and
d
nucleic acid.
Catabolism, the opposite of anabolism,
produces smaller molecules used by the
cell to synthesize larger molecules
ATP und NADH
ATP is consumed in the cell by energy-requiring (endothermic) processes and
can be generated by energy-releasing (exothermic) processes. In this way ATP
transfers energy
energ between
bet een spatiall
spatially-separate
separate metabolic reactions
reactions. ATP is the main
energy source for the majority of cellular functions. This includes the synthesis of
macromolecules, including DNA and RNA (see below), and proteins. ATP also
plays a critical role in the transport of macromolecules across cell membranes
membranes,
e.g. exocytosis and endocytosis.
ATP iis consumed
d iin th
the cell
ll by
b energy-requiring
i i (endothermic)
( d th
i ) processes andd can be
b generated
t d by
b
energy-releasing (exothermic) processes. In this way ATP transfers energy between spatially-separate
metabolic reactions. ATP is the main energy source for the majority of cellular functions. This includes
the synthesis
y
of macromolecules,, includingg DNA and RNA,, and pproteins. ATP also pplays
y a critical role
in the transport of macromolecules across cell membranes, e.g. exocytosis and endocytosis.
Adenosintriphosphat
8 kcal/mol
ATP consists of adenosin — composed of an adenine ring and a ribose sugar —
and three phosphate groups (triphosphate). The phosphoryl groups, starting with
the group closest to the ribose, are referred to as the alpha (α), beta (β), and
gamma (γ) phosphates..
ATP + H2O → ADP + Pi ∆G˚ = −30.5 kJ/mol (−7.3 kcal/mol)
ATP + H2O → AMP + PPi ∆G˚ = −45.6 kJ/mol (−10.9 kcal/mol)
Stoffwechselwege
Metabolismus
Glycolysis
Glycolysis
Glycolysis is the metabolic pathway that converts glucose C6H12O6, into
pyruvate CH3COCOO− + H+.
pyruvate,
The free energy released in this process is used to form the high-energy
compounds ATP (adenosine triphosphat) and NADH (reduced nicotinamide
adenine dinucleotide).
Entner-Doudoroff-Pathway
Entner–Doudoroff pathway
The Entner–Doudoroff pathway describes an alternate series of reactions that
catabolize glucose to pyruvate using a set of enzymes different from those used
in either glycoloysis or the pentose phosphat pathway.
Most bacteria use glycolysis and the pentose phosphate pathway
pathway.
Citrat acid cycle
Citrat acid cycle
In aerobic organisms, the citric acid cycle is part of a metabolic pathway involved
in the chemical conversion of carbohydrates
carbohydrates, fats and proteins into carbon
dioxide and water to generate a form of usable energy.
Other relevant reactions in the pathway include those in glycolysis and pyruvat
oxidation before the citric acid cycle, and oxidative phosphorylation after it.
In addition, it provides precursors for many compounds including some amino
performing
g fermentation.
acids and is therefore functional even in cells p
Signal transduction
Signal transduction is the process by which an extracellular signaling molecule
activates a membrane receptor, that in turn alters intracellular molecules creating
a response
response.
There are two stages in this process: 1) a signalling molecule activates a certain
receptor on the cell membrane 2) causing a second messenger to continue the
signal into the cell and elicit a physiological response.
p, the signal
g
can be amplified,
p
, meaning
g that one signalling
g
g molecule
In either step,
can cause many responses.
Signaling pathways
Signaling pathways
EGF Pathway