synthesis of sucrose presented by kulsoom pirjan baloch
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Kulsoom pirjan
sucrose
Sub topics
1.. carbohydrates 8.. Regulation of sucrose
2.. Chemical groups of carboydrates 9.. Degradation of sucrose.
3.. Importance of carbohydrates
4.. Sucrose introduction
5.. Carbohydrates biosynthesis
6.. Synthesis of sucrose
• Carbohydrates are one of the main types of
nutrients. They are the most important source of
energy for your body. Your digestive system
changes carbohydrates into glucose (blood
sugar). Your body uses this sugar for energy for
your cells, tissues and organs.
• A carbohydrate is a biological molecule
consisting of carbon (C), hydrogen (H) and
oxygen (O) atoms, usually with a hydrogen:
oxygen atom ratio of 2:1 (as in water).
• carbohydrate, with the empirical formula
Cm(H2O)n (where m could be different from n).
• The term is most common in biochemistry, where
it is a synonym of saccharide, a group that
includes sugars, starch, and cellulose.
• Carbohydrates are technically hydrates of
carbon.
• Monosaccharides are the simplest carbohydrates
in that they cannot be hydrolyzed to smaller
carbo-hydrates.
• Monosaccharides are important fuel molecules
as well as building blocks for nucleic acids.
• Two joined monosaccharides are called a
disaccharide and these are the simplest
polysaccharides.
• I .e sucrose , lactose and maltose
• A chain of two or more monosaccharides. The
chain may be branched (molecule is like a tree
with branches and twigs) or unbranched
(molecule is a straight line with no twigs).
Polysaccharide molecule chains may be made
up of hundreds or thousands of
monosaccharides.
• Polysaccharides are polymers. A simple
compound is a monomer,
• Carbohydrates are initially synthesized in plants from a
complex series of reactions involving photosynthesis.
• Store energy in the form of starch (photosynthesis in plants)
or glycogen (in animals and humans).
• Provide energy through metabolism pathways and cycles.
• Supply carbon for synthesis of other compounds.
• Form structural components in cells and tissues
• Sucrose is a common, naturally occurring
carbohydrate found in many plants and plant
parts. Saccharose is an obsolete name for
sugars in general, especially sucrose.
• Molar mass: 342.2965 g/mol
• Formula: C12H22O11
• Density: 1.59 g/cm³
• Melting point: 186 °C
• Soluble in: Properties of water
• The molecule is a disaccharide combination of
the monosaccharides glucose and fructose with
the formula C12H22O11.
• Sucrose commonly called table sugar.
• Sucrose is often extracted and refined from
either cane or beet sugar for human
consumption.
• Modern industrial sugar refinement processes
often involves bleaching and crystallization also,
producing a white, odorless, crystalline powder
with a sweet taste of pure sucrose, devoid of
vitamins and minerals. This refined form of
sucrose is commonly referred to as table sugar
or just sugar
• About 175 million metric tons of sucrose sugar
were produced worldwide in 2013.
• In Nature, sucrose is present in many plants, and
in particular their roots, fruits and nectars,
because it serves as a way to store energy,
primarily from photosynthesis.
• Plants and photosynthetic micro organisms, can
synthesize carbohydrates from CO2 and water,
reducing CO2 at the expense of the energy and
reducing power furnished by the ATP and
NADPH that are generated by the light-
dependent reactions of photosynthesis .
• Green plants contain in their chloroplasts unique
enzymatic machinery that catalyzes the conversion
of CO2 to simple (reduced) organic compounds, a
process called CO2 assimilation. This process has
also been called CO2 fixation or carbon fixation
• but we reserve these terms for the specific reaction
in which CO2 is incorporated (fixed) into a three-
carbon organic compound, the triose phosphate 3-
phosphoglycerate
• Most of the triose phosphate generated by CO2 fixation
in plants is converted to sucrose or starch.
• In the course of evolution, sucrose may have been
selected as the transport form of carbon because of its
unusual linkage between the anomeric C-1 of glucose
and the anomeric C-2 of fructose.
• It is a carbon fixation pathway present in some
plants also known as CAM photosynthesis .
• These plants fix carbon dioxide( CO2) during the
night storing it as the 4 – carbon acid malate.
• Triose phosphates produced by the Calvin cycle
in bright sunlight, as we have noted, may be
stored temporarily in the chloroplast as starch, or
converted to sucrose and exported to non-
photosynthetic parts of the plant, or both. The
balance between the two processes is tightly
regulated, and both must be coordinated with the
rate of carbon fixation.
• Five-sixths of the triose phosphate formed in the
Calvin cycle must be recycled to ribulose 1,5-
bisphosphate, if more than one-sixth of the triose
phosphate is drawn out of the cycle to make
sucrose and starch, the cycle will slow or stop.
• Regulation of sucrose also responsible for the
gene expressions .
• Sucrose is the world’s most abundant disaccharide, it is only produced by photosynthetic organisms and serves a role as a transportable carbohydrate and sometimes as a storage compound. The reactions in plant tissues leading to degradation of sucrose to hexose monophosphates .
• Plant tissues contain distinct invertases located in the vacuole, cell wall (acid invertases) cytosol, mitochondria, nucleus, and cholorplast which hydrolyse sucrose to glucose and fructose in an irreversible reaction.
• The first step is cleavage of the glycosidic bond
by either invertase (Equation 1) or sucrose
synthase (Equation 2)
• Sucrose + H2O→D-Glucose + D-Fructose(1)
• Sucrose + UDP→UDP-Glucose + D-Fructose(2)
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