Biomolecules | Carbohydrates, Lipids, and Proteins

Running head: BIOMOLECULES
BIOMOLECULES
Name of the Student
Name of the University
Author Note

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BIOMOLECULES
Part A- Carbohydrates
1. The straight chain structure of glucose have functional groups including aldehyde
group attached on carbon 1 and alcohol groups attached on carbon 2 to carbon 6.
However, in the cyclic form, the functional group present in carbon 1 is hemiacetal
group. Glucose contains polar hydroxyl groups in abundance, which forms hydrogen
bond with molecules of water and thus is highly soluble in water.
Glucose is the primary source of energy that is required for the cells to
function properly and to support the metabolism of the body.
2. Glycogen is primarily work as the storage of glucose and providing it to the body
during starvation. It is present in abundance in liver and muscles.
Glycogen is a polysaccharide, which is made up of numerous glucose
monomers.
3. The chief anatomical differences between starch and cellulose are starch consists of
alpha glucose and cellulose is made of beta glucose. The starch molecule can form
both straight chains and helical structures whereas, cellulose can only form straight
chains. Functionally, human and animal as source of energy use starch whereas
exclusively plants for providing structural integrity use cellulose.
Human body can use starch as a source of energy as it is made of numerous
monomers of glucose and glucose is the unit of energy that can be used by the body to
function properly. Cellulose is not produced in the human body nor it can be digested
on consumption. On consumption, it comes out in the form of faeces and thus, it
cannot be considered as the source of energy.

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4. Maltose is made of two units of glucose monomers. Lactose is made of one monomer
of glucose and one monomer of galactose. Sucrose is made of one monomer of
glucose and one monomer of fructose.
Maltose is found in germinating grains. Lactose is found in milk. Sucrose is
found in sugarcane plants from which, table sugar is prepared.
5. Lactose intolerance is the condition in which the small intestine becomes incapable of
producing the enzyme lactase for breaking down lactose present in milk (Adeva-
Andany, González-Lucán, Donapetry-García, Fernández-Fernández & Ameneiros-
Rodríguez, 2016).
Part B- Lipids
1. Four major functions of lipid in the human body are: it is used as chemical
messengers to convey signals between organelles and cells; it is used in maintaining
the body temperature; it is used in the formation of cell membrane and in formation
of prostaglandins used in relaxation and contraction of muscles.
2. Triacylglycerol is used in the production of energy. To produce energy from
triacylglycerol it first needs to be hydrolysed which, occurs in a few steps. The
hydrolysis of triacylglycerol occurs in the adipose tissue by the action of the enzyme
lipase. In the first main step, lipase acts on triacylglycerol to produce diacylglycerol
with the liberation of fatty acid. In the second step, lipase acts on diacylglycerol to
produce monoacylglycerol and fatty acid is also liberated. In the final main step,
lipase acts on monoacylglycerol to produce fatty acid along with glycerol.
3. The only characteristic that is common in all lipids is they lack the capability of
getting dissolved in water.

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4. Lipid is the ideal component for building cell membrane. This is because lipid
consists of hydrophilic head and hydrophobic tail. This amphipathic nature restricts
the movement of both water soluble and polar components to move across the cell
membrane.
The cell membrane are composed of mainly four components that are
phospholipids, glycolipids, proteins and cholesterol. The major roles of
phospholipids include the formation of cell membrane. It also acts as barrier to the
cellular components. The other functions of phospholipids are exocytosis,
endocytosis, chemokinesis and chemotaxis. They are also observed to play a role in
active phagocytosis. The major role of cholesterol is to maintain and regulate the
fluidity of cell membrane owing to it’s large structure and also protect the cell from
adverse effects of temperature changing.
The proteins taking part in transport across cell membrane are known as
transport proteins. There transport proteins can be found in two or three types, which
are channel protein and carrier protein. The transport proteins play key roles in
transporting molecules across cell membrane by both active transport and passive
transport (Shpilka et al., 2015).
Part C- Proteins
1. Proteins help in digesting food by acting on the food as enzymes such as lipase.
Proteins like actin build up the cytoskeleton structure thus, providing a structural
integrity. Proteins carry out the coordination of various body systems by acting as
hormone like insulin. Protein molecules like haemoglobin are circulated throughout
the body to perform various related functions. Protein molecule such as
immunoglobulin functions as the defense mechanism of human body. Protein like
albumin provides nourishment to the human body and facilitates growth.

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2. The structure of glutathione is made up of three amino acids, which include cysteine,
glutamic acid and glycine that form a tripeptide.
3. a. Lysozyme, an enzyme gets denatured by the action of high temperature. High
temperature greater than equal to 100°C causes the enzyme to denature with an
irreversible effect. During the initial stage of heating, the structure of protein gets
altered through unfolding from the tertiary structure to secondary structure. Water
acts as a stabilizing agent for the two dimensional structure of the protein. During
heating, the hydrogen bond gets dissociated. This causes the enzyme to lose its
catalytic activity because the catalytic subunit changes its structure.
b. Physical denaturing agents apart from heat includes ultraviolet ray and high
pressure. Chemical denaturing agents include acids and alkalis.
4. Competitive inhibition of enzyme is a process in which the reaction of enzyme is
inhibited. It is reversible in nature. The enzyme only functions properly when it binds
to a substrate. However, in competitive inhibition, the substrate and an inhibitor
which is structurally similar to the substrate competes for binding to the enzyme
active site and on binding to the enzyme inhibits its function. Examples of
competitive inhibitor include malonate and oxaloacetate (Singh et al., 2017).
Part D- Nucleic acids/ cells/ transport
1. Adenosine Triphosphate or ATP is made up of an adenosine ring attached to a ribose
sugar and three phosphate groups attached to the ribose ring. ATP molecules are the
main source of energy for the body. It also takes part in each and every metabolism
and normal body functions.
2. a. Deoxyribonucleic acid or DNA is the basic nucleic acid structure present in every
cell of the body which contains all the genetic and hereditary information necessary
for proper functioning of the body, growth and development.

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b. DNA replication is the process by which a DNA replicates and produces an exact
copy of itself during the cell division. The two daughter cells produced from division
of a mother cell contains two copies that was replicated from a single DNA.
c. Helicase is specific class of enzymes enables the DNA double helix to get
separated in two single strands during replication. Another class of enzymes DNA
polymerase facilitates creation of double helix DNA strand by incorporating
complementary nucleotides with respect to the nucleotides present in the single strand
of DNA (National Human Genome Research Institute, 2020).
3. Simple diffusion is a mode of transport in which solutes transported from a higher
concentration region to a lower concentration region via a semipermeable membrane.
Facilitated diffusion is a process of passive transport in which ions or molecules move
across the cell membrane by the action of transmembrane proteins. Active transport
can be defined as the movements of molecules or ions from a lower concentration to
a higher concentration region via cell membrane.
4. The main components of eukaryotic cells are nucleus, cell membrane, ribosome and
different cell organelles. Mitochondria is known as the powerhouse of the cell as it
supplies ATP for whatever function it is needed for and also performs cellular
respiration (Archibald, 2015).

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REFERENCES
Adeva-Andany, M. M., González-Lucán, M., Donapetry-García, C., Fernández-Fernández,
C., & Ameneiros-Rodríguez, E. (2016). Glycogen metabolism in humans. BBA
clinical, 5, 85-100.
Archibald, J. M. (2015). Endosymbiosis and eukaryotic cell evolution. Current
Biology, 25(19), R911-R921.
National Human Genome Research Institute. (2020). Deoxyribonucleic Acid (DNA).
Retrieved 31 March 2020, from
https://www.genome.gov/genetics-glossary/Deoxyribonucleic-Acid
Shpilka, T., Welter, E., Borovsky, N., Amar, N., Mari, M., Reggiori, F., & Elazar, Z. (2015).
Lipid droplets and their component triglycerides and steryl esters regulate
autophagosome biogenesis. The EMBO journal, 34(16), 2117-2131.
Singh, M., Weerathunge, P., Liyanage, P. D., Mayes, E., Ramanathan, R., & Bansal, V.
(2017). Competitive inhibition of the enzyme-mimic activity of Gd-based nanorods
toward highly specific colorimetric sensing of l-cysteine. Langmuir, 33(38), 10006-
10015.