Seatwork No.2
Protein
Name: Rizaga, Carlos Benedict C.
Section: BSN – 1N
Score: ______________
Date: 12/13/2022
Place your answers in MS Word. Submit the file in pdf format.
I. Discuss Briefly.
1.
All protein contains which elements and their percentage amount?
 Proteins contain the elements carbon, hydrogen, and oxygen just as carbohydrates
and lipids do, but proteins are the only macronutrient that contains nitrogen.
Carbon – 50 %
Hydrogen – 7 %
Oxygen – 23 %
Nitrogen – 16 %
Sulfur – 0-3 %
Phosphorus – 0-3 %
2.
Differentiate essential and non –essential amino acid.
 Essential amino acids, also known as "indispensable amino acids", are those that must
come from a person’s diet because the human body lacks the metabolic pathways
required to synthesis these amino acids. The amino acids that are not essential for the
human body (also known as “dispensable amino acids”) can be synthesized by the
body. In other words, the body can produce them without needing dietary help.
3.
Describe the type of protein structures.
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Primary - The primary structure of a protein is the amino acid sequence of the chain.
Amino acids are linked by peptide bonds to form polypeptides chain. By convention,
the amino end (N terminal) is the beginning of the polypeptide chain and the carboxyl
(C-terminal) is the opposite end
Secondary - It refers on the regularly repeating local structures stabilized by hydrogen
bonds. most common examples are alpha helix and beta sheet. Because secondary
structures are local, many regions of different secondary structure can be present in
the same protein.
Tertiary - Refers to the specific folding and bending of the coils into specific layers and
gives proteins their specific biologic activity. The overall shape of a single protein
molecule; the spatial relationship of the secondary structures to one another
Quaternary - The shape or structure that results from the interaction of more than one
protein molecule, usually called protein subunits in this context, which function as part
of the larger assembly or protein complex. This occurs when two or more protein units,
each with own primary, secondary & tertiary structure; combine to form a more
complex unit.
4.
Which is better to eat before taking an exam – a piece of cheese or a glass of milk?
Why?
 Before and examination, it would be better to eat a piece of cheese instead of a
glass of milk. Cheese contains high amounts of tyramine which mimics the
neurotransmitter epinephrine. Epinephrine has a stimulatory effect and stimulates the
brain to be more alert
Chapter 4: Proteins
Page 1