Plant Cell Chemistry
and Physiology
BOT 1P: Lecture 4
Classification of Chemical
Substance
I. Inorganic substances
II. Organic substances
Inorganic Substances
• Compounds that do not contain
carbon (except CO2, CO, carbonates
and cyanide)
• With ionic bond
• (An ion is an atom or molecule which
has lost or gained one or more
valence electrons, giving it a positive
or negative electrical charge)
Ex. Sodium, potassium, calcium
Ionic Bond
Inorganic Substances
A. Water
• The most abundant inorganic
compound
• Solvent that dissolves ions and
molecules and leaving the cell
• One of the raw materials needed for
photosynthesis
• Provides pressure needed for the
maintenance of cell form
• Absorbs heat
B. Gases
• CO2 – raw material for
photosynthesis
• O2 – raw material for cellular
respiration
• Cellular Respiration- an essential
biological process that extracts
energy from foods in a usable,
chemical form known as adensosine
triphosphate, or ATP.
C. Mineral Salts
• Compounds formed when an acid is
combined by a base
• Serves as raw material together with
CO2 and water that are used to
synthesize the many complex
organic materials in the cell
• Maintains osmotic pressure and acidbase balance
Organic Substances
• Carbon-containing compounds
• With covalent bond
Example:
A.Carbohydrates
B.Lipids
C.Proteins
D.Nucleic acids
Covalent Bond
The Macromolecules within
Cells
A. Carbohydrates
• Main source of cellular energy
• Organic compound containing C, H,
and O atoms with the general formula
CH2ON
• Types of Carbohydrates:
1.Monosaccharides
A. Glucose
B. Fructose
C. Galactose
2. Disaccharides
a. Sucrose
b. Maltose
3. Polysaccharides
a. Cellulose
b. Starch
B. Lipids
• Storage form of energy
• Composed of fatty acids and glycerol
• Examples:
a.Suberin
b.Cutin
c.Waxes
Hormones
• Chemical messengers present in very
small amounts that bring about
important changes in growth and
development
• Examples:
1. Auxin
2. Cytokinin
3. Gibberellic acid
4. Abscisic acid
5. ethylene
C. Proteins
• Composed of amino acids
• Example: Enzymes and Pigments
Enzymes
• Any of various proteins, as pepsin
originating from living cells and capable of
certain chemical changes in organic
substances by catalytic increase, the rate
of a chemical reaction as in digestion.
• Pigments
Types of pigments:
A. Water-soluble pigments found in the
vacuoles like anthocyanin ( may appear
red, purple, or blue according to the pH)
and anthoxanthin (clear, white to yellow
counterparts)
B. Lipid-soluble pigments found in the
plastids like chlorophyll (green),
carotenes (orange) and xanthophylls
(yellow)
Other pigments are:
• Phytochrome - is a photoreceptor,
a pigment that plants use to detect
light
• Riboflavin (yellow)- vitamin found in
eggs, liver, green vegetables, milk and
yeast
• Cytochromes- carry out electron
transport
D. Nucleic acids
• Made up of nucleotides
• Kinds:
1. DNA
2. RNA
Physiological Processes
Occurring in Plant Cells
1. Absorbing the material such as
water, mineral, salts and gases
from the environment while
simultaneously losing material to it
by means of some processes like
imbibition, osmosis and
plasmolysis
2. Building foods from the materials and
light energy it absorbs through a
process called photosynthesis.
3. Changing complex foods to simple form
by digestion.
4. Releasing the energy in the food for its
varied activities through a process
called respiration.
6.Incresing in size or growth by
intussusception.
7. Producing new cells by cell
division.
Study Hard! God bless!
Thank you for listening 