Other types of sugar polymers make up the stored

Other types of sugar polymers make up the stored forms of energy known as starch
and glycogen . Starch is found in plant products such as potatoes, and glycogen is
found in animals.
Proteins
Proteins are another class of indispensable biomolecules, which make up around 50
percent of the cellular dry weight. Proteins are comprised of the elements carbon,
nitrogen, oxygen, hydrogen and sometimes sulfur. Proteins are polymers of amino
acids, arranged in the form of chain called polypeptide. Depending on how the
structure of a protein is arranged, it gives rise to a certain level of structural
organization. The level can be classified as primary, secondary, tertiary and
quaternary .
Proteins play both structural and dynamic roles. They help form many of the
structural features of the body including hair, nails and muscles. Myosin is the
protein that allows movement by contraction of muscles Proteins are also present as
a major component of cell membranes. Being part of cell membranes, proteins act
as carriers or channels, facilitating the movement of ions and molecules in and out
of the cells. Ions like sodium, potassium and chloride, molecules like glucose are
maintained at proper concentration for cells to function normally. Proteins also acts
as catalyst. A large group of proteins, known as enzymes, enable the cells to carry
out chemical reactions fast. In order for the organism to maintain growth and
survival, the food being consumed must be converted to energy at an appreciable
rate.
Lipids
The term lipid refers to a wide variety of biomolecules including fats, oils, waxes and
steroid hormones. Regardless of their structure, location or function in a cell/body,
all lipids share common features that enable them to be grouped together. They do
not dissolve in water; they are hydrophobic. The hydrophobic nature of the lipids
dictates many of their uses in biological systems. Lipids are composed primarily of
carbon, hydrogen, oxygen, phosphorus and sulfur (lipids also contain nitrogen
in some cases) . Fats are a good source of stored energy while oils and waxes are
used to form protective layers on our skin, preventing infection. Some lipids, the
steroid hormones, are important regulators of cell activity. The activities of steroid
hormones such as estrogen have been implicated in cancers of the female
reproductive system.

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CO_Q4_Science 10_ Module 2
Nucleic Acids
Nucleic acid, naturally occurring chemical compound that is capable of being broken
down to yield phosphoric acid, sugars, and a mixture of organic bases (purines and
pyrimidines). Nucleic acids are the main information-carrying molecules of the cell,
and, by directing the process of protein synthesis, they determine the inherited
characteristics of every living thing. These molecules are comprised of elements
carbon, hydrogen, oxygen, phosphorus and nitrogen. The two main classes of
nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) .