Carbohydrate

Carbohydrate:
A large group of organic compound and it’s most abundant macro or biological molecule on Earth. It consists of Carbon (C), Hydrogen (H), and Oxygen (O) usually in the ratio of (1:2:1) and naturally can be broken down to release energy in the animal body. General formula of carbohydrate is (C16H12O6). Carbohydrates are formed by the photosynthesis of green plants (CO2) and Water (H2O). Some carbohydrates are relatively small, with smallest units of molecular weights of less than 100. They act as source of energy others are true macromolecules, with smallest molecular units of weights in the hundreds of thousands. It’s one of the four macro-molecule of cell. Carbohydrate also called saccharides. The word saccharide is derived from the Greek word …….. .

Carbohydrates are the most abundant bio-molecules on earth they are found everywhere carbohydrates are a major source of energy for all living organisms such as animals and plants but they are not only important for energy carbohydrates also serve as important structural components for example DNA contained the carbohydrate ribose and the plant cell wall are made up of the carbohydrates cellulose.

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Carbohydrates mainly contain carbon hydrogen and oxygen atoms in a molar ratio of one to one carbon two hydrogen and one oxygen atoms. Carbohydrates can be divided into four types these are monosaccharides disaccharides oligosaccharides and polysaccharides. The word saccharide word is derived from the Greek word for sugar.

now let us look at each of these types of carbohydrates and learn a bit more about their structure and how they are formed this is a biochemistry lesson let’s begin with monosaccharides monosaccharides are also referred to as simple sugars and they are the smallest units that make up any carbohydrate they are the building blocks the three main monosaccharides in
the human diet include glucose galactose and fructose now these structures may look intimidating but all you need to know is that they contain carbons hydrogen’s and oxygens let’s look at glucose first which you all probably have heard of blook glucose is the main source of
energy for humans here you can see glucose in its cyclic chemical form what’s important to know about glucose is that it contains six carbon atoms so let’s have a closer look here see represents a carbon atom and we can label these carbon atoms of glucose with numbers one two three four five six in this specific order so glucose has six carbon atoms this particular type of glucose is actually an alpha glucose because it has an alpha configuration alpha carbohydrates is where the hydroxyl group the O H group of carbon number one is pointing in the opposite
direction to the carbon number six so these are opposite each other and there is another type of glucose known as a beta glucose this is essentially where the hydroxyl group of carbon number one and carbon number six are pointing in the same direction so B two carbohydrates is where the hydroxyl group of carbon number one is pointing in the same direction as carbon number six and again these alpha and beta carbohydrates they also apply to other types of carbohydrates such as galactose as well as fructose so for example this galactose molecule is actually a beta galactose because the hydroxyl group here and the carbon number six is pointing in the same direction similarly this fructose here is actually in a beta configuration so it’s a bead of fructose because the hydroxyl group here is pointing in the ame direction as carbon number six so I hope you understood the structure of the three major monosaccharides in the human diet now let’s look at disaccharides disaccharides are made up of two monosaccharides so for example a glucose molecule and another glucose molecule
can form a bond with each other this new disaccharide is called molto’s maltose is essentially two glucose molecules linked together it is inked
together by an alpha 1 to 4 glycosidic
bond
it’s called alpha 1 to 4 glycosidic bond
because carbon number 1 of this glucose
and carbon number 4 of this glucose are
involved in the linking process and it’s
called alpha because both these glucose
molecules are in an alpha configuration
now the process of linking
monosaccharides with one another is
called condensation and here water is
released
therefore the reverse reaction is
hydrolysis and this is where we add
water adding water to an alpha 1 2 4
glycosidic bond will break the bond
so molto’s is only one example of a
disaccharide let’s look at some other
common examples
now this galactose molecule can link
with a glucose molecule so this
particular glucose molecule is actually
in a beta configuration because remember
the hydroxyl group here is in pointing
the same direction as carbon number 6
so this galactose molecule and the
glucose molecule can form a link and
through the condensation process it will
form lactose lactose is made up of
galactose and glucose the galactose and
glucose is linked together by a beta 1
to 4 glycosidic bond now it is called a
beta 1 2 4 glycosidic bond because the
the galactose and glucose are in a beta
configuration and also carbon number 1
and carbon number 4 are involved the
reverse reaction to break lactose
requires hydrolysis by adding water now
lactose as you all probably know is
found naturally in milk
the third type of disaccharide I want to
talk about is where we form a bond
between one glucose molecule and one
fructose this glucose molecule is an
alpha glucose because the as you can see
the hydroxyl and carbon number six are
pointing the opposite direction so
glucose and fructose can form a link and
through the condensation reaction
removal of water it can form a
disaccharide called sucrose sucrose is
made up of one glucose and one fructose
the bond between the glucose and
fructose is a little more complicated as
it is our glucose alpha one and fructose
beta two bond this sort of linking
occurs so the glucose is in an alpha
configuration and the fructose is in a
bead of configuration and it’s carbon
number one of glucose and carbon number
two of fructose that are involved in the
linking process
so essentially fructose flips over
sucrose as you all know is table sugar
and is formed by plants and not formed
by animals so humans cannot form sucrose
sucrose is broken down through a
hydrolysis reaction so the disaccharides
maltose lactose and sucrose are all good
examples that we encounter in our normal
diet now let’s look at oligosaccharides
all of those saccharides basically
consists of short chains of
monosaccharides typically less than 20
monosaccharides linked together actually
a disaccharide can be referred to as an
oligosaccharide now let’s look at an
example of an oligosaccharide so if we
were to take this molto’s and add
another glucose molecule to it
through a condensation reaction again we
can form a ditional alpha one two four
glycosidic bond this oligosaccharide is
called molto trios try as in three and
this moto triose is made up of glucose
and they’re linked together as I
mentioned by alpha one two four
glycosidic bonds to break down these
bonds requires hydrolysis the addition
of water and the structure can keep
growing with the addition of more
glucose molecules but when the
oligosaccharide eventually exceeds 20
monosaccharides with 20 bonds the
carbohydrate is then referred to as a
polysaccharide so from an
oligosaccharide it becomes a
polysaccharide
most carbohydrates found in nature occur
as polysaccharides polysaccharides are
also known as glycans to simplify things
polysaccharides can be a homo
polysaccharide or they can be a hetero
polysaccharide a homo polysaccharide
means the polysaccharide only contains a
single type of monosaccharides
for example it only contains glucose
molecules linked together a hetero
polysaccharide means that the
polysaccharide contains two or more
different monosaccharides so for example
a long chain of fructose and glucose
molecules to make things a little bit
more interesting a polysaccharide can
also be unbranched like what you see
here or it can be branched this goes for
both homo polysaccharides as well as
hetero polysaccharides hetero
polysaccharides can also be unbranched
or branched what you have to understand
is that polysaccharides I am currently
drawing is are very small in reality the
polysaccharide contains thousands are
made up of thousands of monosaccharides
linked together in this section of the
video we won’t focus on hitch
saccharides but we will look at homo
polish seconds because hobo
polysaccharides serve as storage forms
of monosaccharides in both humans and
plants and even bacteria so they’re very
very important so let’s look at some
examples of homo polysaccharides starch
is a storage form of monosaccharides in
plants starch is the main carbohydrate
in the human diet and are found in our
bread cereal and rice starch is only
made up of glucose because it is a homo
polysaccharide let us zoom into this
area here and learn a bit about the
bonds so here we have our regular alpha
1 2 4 glycosidic bond between two
glucose molecules and this is because
carbon number 1 and carbon number four
of these glucose molecules are involved
in the linking process however the
branching points here is actually an
alpha 1 to 6 glycosidic bond between two
glucose molecules and that is because
carbon number 1 of this glucose and
carbon number 6 here are involved in the
linking process so what you take out of
this is that starch has two forms it can
be branched like what I just explained
or starch can be unbranched if starch is
unbranched so it is only a chain of
glucose linked together by alpha one to
four glycosidic bonds it is referred to
as amylose if starch is branched it
contains both alpha 1 to 4 and alpha 1
to 6 glycosidic bonds between glucose
and therefore it is referred to as
amylopectin amylose and amylopectin are
two forms of glucose polymers the other
good example of a polysaccharide is
glycogen now glycogen is a homo
polysaccharide because it is made up of
glucose glycogen can also be
branched or unbranched glycogen is a
storage form of glucose in animals such
as humans starch and glycogen are
actually very similar in structure
they both are made up of glucose and
they can either be branched or
unbranched so both starch and glycogen
contain amylose and amylopectin the only
difference is that glycogen has these
branch points occurring every eight to
twelve glucose residues in starch these
branch points occur every 24 to 30
glucose residues so the branch points
occur more frequently in glycogen and
starch and this of course will influence
the structure in some way another type
of polysaccharide is DIC strands DIC
strains are structural components in
bacteria and yeast these polysaccharides
are made up of alpha 1 2 3 and alpha 1 2
6
glycosidic bonds so here we have glucose
units with alpha 1 2 3 bonds and alpha 1
to 6 bonds however the dick strands can
also contain alpha 1 2 2 and alpha 1 2 4
glycosidic bonds finally the other
polysaccharide worth mentioning is
cellulose cellulose are structural
components in plants they make up the
plant cell wall they are unbranched homo
polysaccharide consisting of thousands
of glucose molecules so here you can see
unbranched cellulose on top of each
other in cellulose the glucose molecules
have a bita configuration and therefore
the bonds between these glucose
molecules are beta bonds the glucose
molecules are linked together by beta
one to four glycosidic bond
humans do not have enzymes that break
down that hydrolyzed beta one to four
glycosidic bonds of cellulose and so
humans cannot digest cellulose
now even though cellulose are only
chains of beta glucose so unbranched
beta glucose these chains can form
hydrogen bonds with each other forming a
very strong structure
. Some carbohydrates are relatively small, with molecular weights of less than 100.

Others are true macromolecules, with molecular weights in the hundreds of thousands.
Carbohydrates come in simple forms such as sugars and in complex forms such as starches and fiber.

Carbohydrate, class of naturally occurring compounds and derivatives formed from them. In the early part of the 19th century, substances such as wood, starch, and linen were found to be composed mainly of molecules containing atoms of carbon (C), hydrogen (H), and oxygen (O) and to have the general formula C6H12O6; other organic molecules with similar formulas were found to have a similar ratio of hydrogen to oxygen. The general formula Cx(H2O)y is commonly used to represent many carbohydrates, which means “watered carbon.”
Carbohydrates are probably the most abundant and widespread organic substances in nature, and they are essential constituents of all living things. Carbohydrates are formed by green plants from carbon dioxide and water during the process of photosynthesis. Carbohydrates serve as energy sources and as essential structural components in organisms; in addition, part of the structure of nucleic acids, which contain genetic information, consists of carbohydrate.

Carbohydrates: Mainly sugars and starches, together constituting one of the three principal types of nutrients used as energy sources (calories) by the body. Carbohydrates can also be defined chemically as neutral compounds of carbon, hydrogen and oxygen.

Carbohydrates come in simple forms such as sugars and in complex forms such as starches and fiber. The body breaks down most sugars and starches into glucose, a simple sugar that the body can use to feed its cells. Complex carbohydrates are derived from plants. Dietary intake of complex carbohydrates can lower blood cholesterol when they are substituted for saturated fat.

Carbohydrates are classified into mono, di, tri, poly and heterosaccharides. The smallest carbohydrates are monosaccharides such as glucose whereas polysaccharides such as starch, cellulose and glycogen can be large and even indeterminate in length.

The energy produced by carbohydrates is 4 calories per gram. Proteins also provide 4 calories per gram. Fats are high-cal; they provide 9 calories per gram.

Etymology: Carbohydrates are called carbohydrates because the carbon, hydrogen and oxygen they contain are usually in the proportion to form water with the general formula Cn(H2O)n.