Olguera, Pauline Anne G.
BSCP 3-3
ANATOMY AND PHYSIOLOGY
Prof. Adrian Guinto
1. A. What is Chemistry?
Chemistry is the science of composition, structure, properties, and
reactions of matter especially of atomic and molecular systems. It is the science
dealing with the composition of matter and the changes in composition that
matter undergoes. It is concerned also with the energy and the energy changes
associated with matter.1
b. Why is it important in biology?
Chemistry is closely related to biology, not only because living
organisms are made of material substances but also because life itself is
essentially a complicated system of interrelated chemical processes. Biological
processes are chemical in nature. The metabolism of food to provide energy ti
living organisms is a chemical process.1
2. Differentiate the meaning of atoms, elements and molecules. Providing the
examples to substantiate your answers.
A. Atoms – is the smallest particle in a substance. It is the fundamental
unit of matter where all substances are formed. It is made of nucleus
which contains protons, neutrons and electrons. Ex. Hydrogen atom
and carbon atom.
B. Elements – An element is a is made of a central nucleus containing
protons (positively-charged) and neutrons (with no charge). The
electrons (negatively-charged with negligible mass) revolve around the
nucleus in different imaginary paths called orbits or shells. Ex. Sulfur,
chlorine
C. Molecules - is formed when atoms of the same or different elements
combine. Ex. Carbon dioxide, Oxygen
1 College Chemistry: An Introduction to General, Organic, and Biochemistry by Hein, Morris; Bert, Reo R.; Pattison, Scott;
Susan Arena, 1993 by Wadworth, Inc. Belmont, California

3. What is the difference of inorganic and organic chemistry?
Inorganic chemistry deals with all other elements as well as with
some carbon compounds. Substances classified as inorganic are derived mainly
from mineral sources rather than form animal or vegetable sources. While
Organic Chemistry is concerned with compounds containing the element carbon.
The term organic was originally derived from the chemistry of living organisms:
plants and animals.
4. What are the 3 types of carbohydrates? Provide a graphical representation of
each.
a. Monosaccharide - used for energy, stored as glycogen, or reacted to
produce fat. This is usually found in honey and fruits. Digestion breaks complex
carbohydrates down to monosaccharide, which are small enough to be
absorbed.2
b. Disaccharide – usually found in milk sugar, cane sugar, beet sugar and
molasses. Simple carbohydrates include this.2

c. Polysaccharide – complex carbohydrates include this which has starch
from plant food and glycogen from meats. Foods containing starch and glycogen
usually have many other nutrients, including valuable vitamins and minerals.2
5. What are the 4 types of proteins according to structure? Briefly describe each
of them and name at least 2 examples of each.
a. Primary Structure – is established by the number, kind, and sequence
of amino acid units composing the polypeptide chain or chains making up the
molecule. The primary structure determines the alignment of side-chain
characteristics, which in turn, determines the three-dimensional shape into which
the protein folds. In this sense the amino acid sequence is of primary importance
in establishing protein shape. Example is the insulin.3
B. Secondary Structure – characterized as a regular, three-dimensional
structure held together by hydrogen bonding between the oxygen an the
hydrogen groups in the polypeptide chains. The helical and pleated-sheet
structures of Pauling and Corey are two examples of secondary structure.4
2 Holes human anatomy and physiology by Shier, David; Buttes, Jackie and Lewis, Ricky, 2004, MCgrawhill.
3 Brocchieri L, Karlin S (2005-06-10). "Protein length in eukaryotic and prokaryotic proteomes". Nucleic Acids Research
33 (10): 3390-3400. doi:10.1093/nar/gki615. PMID 15951512.

4 Pauling L, Corey RB, Branson HR (1951). "The structure of proteins; two hydrogen-bonded helical configurations of the
polypeptide chain". Proc Natl Acad Sci USA 37 (4): 205-211. doi:10.1073/pnas.37.4.205. PMID 14816373.
C. Tertiary Structure – refers to the distinctive and characteristic
conformation, or shape, of a protein molecule. This overall three-dimensional
conformation is held together by a variety of interactions between amino acid
side chains. The tertiary structure depends on the number and location of these
interactions, variables that are fixed when the primary structure is synthesized.
Thus, the tertiary structure depends on the primary structure. Examples are
myoglobin which has a folded sausage structure, and hair which is rich in
disulfide bonds.
d. Quaternary Structure – it is found in some complex proteins. These
proteins are made up of two or more smaller protein subunits. The quaternary
structure refers to the shape of the entire complex molecule and is determined by
the way in which the subunits are held together by noncovalent bonds. Examples
are Triose phosphate isomerase which is an enzyme used in glucose
metabolism, and flavodoxin which is a conjugated protein found in some
bacteria.5
5 Chiang YS, Gelfand TI, Kister AE, Gelfand IM (2007). "New classification of supersecondary structures of
sandwich-like proteins uncovers strict patterns of strand assemblage.". Proteins. 68 (4): 915–921.
doi:10.1002/prot.21473. PMID 17557333.