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Polysaccharides

Polysaccharides can contain a few to a thousand or more monosaccharides. Three are important to the body ( [link] ):

  • Starches are polymers of glucose. They occur in long chains called amylose or branched chains called amylopectin, both of which are stored in plant-based foods and are relatively easy to digest.
  • Glycogen is also a polymer of glucose, but it is stored in the tissues of animals, especially in the muscles and liver. It is not considered a dietary carbohydrate because very little glycogen remains in animal tissues after slaughter; however, the human body stores excess glucose as glycogen, again, in the muscles and liver.
  • Cellulose, a polysaccharide that is the primary component of the cell wall of green plants, is the component of plant food referred to as “fiber”. In humans, cellulose/fiber is not digestible; however, dietary fiber has many health benefits. It helps you feel full so you eat less, it promotes a healthy digestive tract, and a diet high in fiber is thought to reduce the risk of heart disease and possibly some forms of cancer.

Three important polysaccharides

This figure shows the structure of starch, glycogen, and cellulose.
Three important polysaccharides are starches, glycogen, and fiber.

Functions of carbohydrates

The body obtains carbohydrates from plant-based foods. Grains, fruits, and legumes and other vegetables provide most of the carbohydrate in the human diet, although lactose is found in dairy products.

Although most body cells can break down other organic compounds for fuel, all body cells can use glucose. Moreover, nerve cells (neurons) in the brain, spinal cord, and through the peripheral nervous system, as well as red blood cells, can use only glucose for fuel. In the breakdown of glucose for energy, molecules of adenosine triphosphate, better known as ATP, are produced. Adenosine triphosphate (ATP) is composed of a ribose sugar, an adenine base, and three phosphate groups. ATP releases free energy when its phosphate bonds are broken, and thus supplies ready energy to the cell. More ATP is produced in the presence of oxygen (O 2 ) than in pathways that do not use oxygen. The overall reaction for the conversion of the energy in glucose to energy stored in ATP can be written:

C 6 H 12 O 6  + 6 O 2    6 CO 2  + 6 H 2 O + ATP

In addition to being a critical fuel source, carbohydrates are present in very small amounts in cells’ structure. For instance, some carbohydrate molecules bind with proteins to produce glycoproteins, and others combine with lipids to produce glycolipids, both of which are found in the membrane that encloses the contents of body cells.

Lipids

A lipid    is one of a highly diverse group of compounds made up mostly of hydrocarbons. The few oxygen atoms they contain are often at the periphery of the molecule. Their nonpolar hydrocarbons make all lipids hydrophobic. In water, lipids do not form a true solution, but they may form an emulsion, which is the term for a mixture of solutions that do not mix well.

Triglycerides

A triglyceride    is one of the most common dietary lipid groups, and the type found most abundantly in body tissues. This compound, which is commonly referred to as a fat, is formed from the synthesis of two types of molecules ( [link] ):

Questions & Answers

sorry I cant see the full question
Jessica Reply
what was the question?
evelyna
what is spine as a bone marking?
John
similar to a crest but raised more
evelyna
pointed process
evelyna
slender
evelyna
pointed projection i meant
evelyna
what fills the hallow space in the middle of bones? thanks
John
marrow
evelyna
bone marrow
evelyna
hey you gotta read a book
evelyna
i just happen to take this bone chapter in my book last week so i remember
evelyna
yeah i should. how about the correct match of the number of tarsal, metatarsal and phalanges?
John
what is the difference between basal laminal and basal membrane
Nartey Reply
If one is missing the opsin which detects wavelengths of approximately 560 nm what color would they be unable to see?
Alicia Reply
how do I explain into details the epithelial tissue
Sir Reply
Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs. An example is the epidermis, the outermost layer of the skin. There are three principal shapes of epithelialcell: squamous, columnar, and cub
DJ
thank you
Sir
explain how the intestinal irritation results in diarrhoea
Sir
what is cerebrospinal fluid
nitesha Reply
Cerebrospinal fluid is a clear, colorless body fluid found in the brain and spinal cord. It is produced by the specialised ependymal cells in the choroid plexuses of the ventricles of the brain, and absorbed in the arachnoid granulations.
DJ
cerebrospinal fluid is the fluid present in the brain and spinal cord
olusoga
it is whitish in colour
olusoga
what are the function of the blood
Hannah Reply
to transport oxygen in hemoglobin and nutrients
Thembani
ok
Hannah
describe the pulmonary circulation
Hannah
Which of the following structures contains membranes with mucus glands and blood vessels to help humidify and warm air?
Sheika Reply
thoracic pump for blood, and lymphatic flow for mucus membranes .
Rugiatu
explanation shortly about organizaton of human body
Maulidi Reply
the human body is the entire structure of a human being.it is composed of many different types of cells that together create tissues and subsequently organ systems.they ensure homeostasis and viability of the human body
Chundu
which is the largest body organ?
Carine Reply
skin
Vinod
hello everyone what is blood carcinoma?
Khabat Reply
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Chundu
Many thanks for your cooperation
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Also please keep all the conversations in English language to be understandable for all users.
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Akash
smallest basic unit of life
Adna Reply
cell
Divya
how does the cell work
Akash
cells in our body together with similar cells and form tissues in our body
Chundu
different kinds of sutures and their functions...
Andy
its cell
Kalka
what is Gross anatomy
susana
gross anatomy is the study of what you can observe of the human body without a microscope.
Jessica
what is smallest bone
Gulista
excuse me if you are questing us or testing our knowledge?
Divya
stapes
Chundu
susana ...gross anatomy this are body structures tht we can see with our naked eyes
Otilie
How to work heart
anjali
how many organs in the body doctor
supreme
cell
Vinod
five vital organ hote hain beta koi mushkil pocho bacho wale question m ni dhekta
DR
beta cell is the basic setrecture and function unit of the body
DR
define the cns Dr. Shahid plz
REEMA
reema... cns .. central nervous system is the one of the two major division of the nervosu system
DR
what are the types of vein
Godwin Reply
what is a bone ?
Amoako Reply
give examples of short bones
Amoako
patella
Adna
how is a bone formed under the endochondral process
Juliet Reply

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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