Kim Janxent P.
Berlon
Grade 9 STE-Platinum (CMT)
Part I
1. Define Biochemistry.
Biochemistry is the study of chemical processes within and relating to living organisms. By controlling
information flow through biochemical signaling and the flow of chemical energy through metabolism,
biochemical processes give rise to the complexity of life. Over the last 40 years, biochemistry has become
so successful at explaining living processes that now almost all areas of the life
sciences from botany to medicine are engaged in biochemical research. Today, the main focus of pure
biochemistry is in understanding how biological molecules give rise to the processes that occur within
living cells, which in turn relates greatly to the study and understanding of whole organisms.
2. Biopolymers are the many large molecules in living systems formed from polymers of much smaller
molecules.
a. Name and described the tree (3) broad categories.
Polynucleotide - which are long polymers, composed of 13 or more nucleotide monomers.
Polypeptides- which are short polymers of amino acids
Polysaccharides- which are often linear bonded polymeric carbohydrate structures
b. Give/ draw the molecular formula of how each category was formed.
3. a. What are proteins?
Proteins are large bio molecules, or macromolecules, consisting of one or more long chains of amino
acid residues. Proteins perform a vast array of functions within living organisms, including catalyzing
metabolic reactions, replication, responding, and transporting molecules from one location to another.
b.1. What are amino acids?
Amino acids are biologically important organic compounds composed of amine (-NH2)
and carboxylic acid (-COOH) functional groups, along with a side-chain specific to each amino acid. The key
elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen, though other elements are found in
the side-chains of certain amino acids. About 500 amino acids are known and can be classified in many
ways.
2. How are they formed?
Amino acids were formed by carbon, hydrogen, oxygen, and nitrogen
3. How do they work?
The twenty-three amino acids are the molecular building blocks of protein. The amino acids can be
divided into two groups: essential amino acids and non-essential amino acids. The nine essential amino
acids are so designated because they must be supplied by the foods we eat. The twelve non-essential
amino acids are so designated based on the body's ability to synthesize them from other amino acids. After
it is transported to the liver is highly dependent upon the body's needs at that moment. Immediately after
exercise, when the muscle is receptive to nutrients and the blood flow to the exercise muscles remain high;
a window of opportunity exists to aid muscular growth and recovery.
4. Describe the primary, secondary and tertiary structures of proteins.
Primary-The primary structure of a protein refers to the linear sequence of amino acids in the polypeptide
chain. The primary structure is held together by covalent bonds such as peptide bonds, which are made
during the process of protein biosynthesis or translation.
Secondary-the most common type of secondary structure in proteins is the alpha-helix. Linus Pauling was
the first to predict the existence of alpha-helices, which was confirmed with the determination of the first
three-dimensional structure of a protein, myoglobin (by Max Perutz and John Kendrew).
Tertiary-The tertiary structure will have a single polypeptide chain "backbone" with one or more protein
secondary structures, the protein domains. Amino acid side chains may interact and bond in a number of
ways. The interactions and bonds of side chains within a particular protein determine its tertiary structure.
5. Describe the role of hydrogen bonding in determining the a-helix structure of a protein.
The role of hydrogen bonding in determining a-helix structure of a protein is those hydrogen bonds
between backbone amino and carbonyl group.
Kim Janxent P. Berlon
Grade 9 STE-Platinum (CMT)
Part II
1. Describe carbohydrates.
Carbohydrate is a biological molecule consisting of carbon (C), hydrogen (H) and oxygen (O)
atoms, usually with a hydrogen: oxygen atom ratio of 2:1 (as in water); in other words, with the empirical
formula Cm(H2O)n .Some exceptions exist; for example, deoxyribose, a sugar component of DNA, has the
empirical formula C5H10O4. Carbohydrates are technically hydrates of carbon; structurally it is more accurate
to view them aspolyhydroxy aldehydes and ketones.
2. a. Distinguish between a monosaccharide and a disaccharide
Monosaccharides are the most basic units of carbohydrates. They are the simplest form of sugar and
are usually colorless, water-soluble, crystalline solids. Some monosaccharides have a sweet taste.
Examples of monosaccharide include glucose (dextrose), fructose (levulose) and galactose.
Monosaccharides are the building blocks of disaccharides (such as sucrose and lactose) and
polysaccharides (such as cellulose and starch). While disaccharide is a sugar (a carbohydrate) composed of
two monosaccharides. It is formed when two sugars are joined together and a molecule of water is removed.
For example, milk sugar (lactose) is made from glucose and galactose whereas cane sugar (sucrose) is
made from glucose and fructose.
b. Name and describe sugars which belong to a monosaccharide and a disaccharide
3 Common Monosaccharides:
Galactose
Present in mammals' milk
(see also the disaccharide Lactose,
which is composed of glucose and
galactose)
Fructose
("Fruit Sugar")
Also known as "Fruit Sugar"
Main sources are many kinds of fruits,
as well as honey.
Glucose
Very important in animal (including
human) physiology, diet and nutrition because glucose is the form of sugar
that is used by the body for energy.
All other carbohydrates, including all
other sugars, are converted into
glucose within the digestive
system (digestive processes)
Present in various forms of vegetation
including many ripe fruits as well as
onions and beetroot.
3 Common Disaccharides:
Lactose
Maltose
Sucrose
Chemically, Lactose (molecule) =
Glucose (molecule) + Galactose
(molecule)
Present in mammals' milk, hence
associated with diary products
Provides mammilian infants with a
source of energy
Chemically, ONE Maltose molecule
consists of TWO Glucose molecules
attachedtogether
Present in cereals e.g. barley
Also known as "Malt Sugar"
Chemically, Sucrose (molecule) =
Glucose (molecule) + Fructose
(molecule)
Common form of sugar obtained from
sugar cane or sugar beet
Also present in some fruits and
vegetables
3. What are polysaccharides? How are they formed?
Polysaccharides are polymeric carbohydrate molecule composed of long chains
of monosaccharide units bound together by glycosidic linkages and on hydrolysis give the
constituent monosaccharides or oligosaccharides. They range in structure from linear to highly branch. They
are formed through enzyme-catalyzed condensation (joining of two molecules with water being a byproduct) reactions between other saccharide units.
The reaction involves the removal of an OH- group from one saccharide and H+ from another. The two units
join through a glycosidic bond to form the di/oligo/poly saccharide and the OH- and H+ join to form water.
This reaction is catalysed by enzymes. In an alpha or beta (1, 4) condensation reaction the glycosidic bond
is between carbons 1 and 4 of the subunits, alpha and beta refer to the orientation of the bond (i.e. above or
below the plane of the sugar ring).
4. Name and describe important polysaccharides which are formed from repeating glucose units.
Nutrition polysaccharides are common sources of energy. Many organisms can easily break down
starches into glucose; however, most organisms cannot metabolize cellulose or other polysaccharides like
chitin and arabinoxylans. These carbohydrate types can be metabolized by some bacteria and protists.
Ruminants and termites, for example, use microorganisms to process cellulose. Even though these
complexes to carbohydrates are not very digestible, they provide important dietary elements for humans.
Called dietary fiber, these carbohydrates enhance digestion among other benefits.
