THE CELL AND ITS FUNCTIONS markers, or cell adhesion molecules
responsible for the adhesion of one cell to
another.
OUTLINE
I. Introduction V. Physical Structure of the Cell
II. Organization of the Cell VI. Locomotion of the Cells
III. Basc Ingredients of the VII. References
Protoplasm
IV. Glycocalyx
I. ORGANIZATION OF THE CELL
● 2 Major parts:
o Nucleus
▪ Nuclear membrane – protect the nucleus from
the rest of the structures of the cytoplasm Figure 1. Types of Proteins
o Cytoplasm
▪ Cytoplasmic membrane – protects the
● Lipids
cytoplasm of the cell from the extracellular
o Phospholipids are the most abundant lipid count
environment
in the cell.
● Protoplasm – everything that makes up the cell
▪ Lipid bilayer – pattern/arrangement of
(cytoplasm + nucleus)
phospholipids.
o Sterols/ Cholesterols – interspersed within the
II. BASIC INGREDIENTS OF THE PROTOPLASM phospholipid bilayer. Sterols give a degree of
fluidity
● Water o Triglycerides or neutral fats – storage form of
o Principal fluid medium EXCEPT for fat cells lipids. This is another form of lipids aside from
o Comprises 70-85% those in the cell membrane, found in adipose
● Ions cells.
o Consists abundantly of sodium & potassium
o Important in chemical reactions and passage of ● Carbohydrates
electrical impulses o Mostly found in the cell membrane and is usually
● Proteins in contact with proteins (glycoproteins)
o Constitute 10-20% of cell mass o Functions of glycoproteins:
o Types: ▪ Receptors
▪ Structural Proteins – are stable and/or fixed. ▪ Attachment
These proteins give structure to the o Another form of carbohydrates aside from those
extracellular and intracellular part of the found in cell membranes would be the storage
human body (found outside and inside the cell) form (glycogen) found in the liver and muscles
▪ Intracellular Structural Proteins – are proteins
inside the cell that mostly maintain the shape III. GLYCOCALYX
of the cell and are also very important in ● Carbohydrates found on the surface of the cell
mitosis. Examples of intracellular proteins: membrane can be seen outside, mostly found in the GI
microtubule networks, spindles tract.
▪ Extracellular Structural Proteins – provides ● Functions of Glycocalyx:
structural scaffolding to surrounding cells. o Attachment of the cell to another (negative
Extracellular structural proteins: collagen, charge repels other objects)
elastic fibers (mostly found in connective o Facilitates the cell to cell interaction and
tissues) recognition
o Protects the cell from outside substances
▪ Functional proteins – could be motile or
adhere to membranous structures. It acts as
enzymes, catalysts of reactions, or those that IV. PHYSICAL STRUCTURE OF THE CELL
are used as passages or channels within the
● The cell is composed of highly organized intracellular
cell membrane. Also serves as identifying
organelles that are interrelated to each other
, ▪ Act as receptors, ligands, or secondary
Cell membrane messengers
● A very fluid bilayer that is thin, pliable, and elastic ▪ Serves as anchor for the cytoskeleton extra-
● Transport proteins are interspersed within the and intracellularly to make it stable
phospholipid bilayer (mostly made up of proteins in o Peripheral Proteins
terms of mass) ▪ Some are attached at the periphery of the
● The lipid bilayer is very permeable to: membrane while some are closely related
a. Oxygen with the integral proteins.
b. Carbon dioxide ▪ Primarily function as enzymes and
c. Alcohol controllers of transport.
Figure 2. The lipid bilayer and its components
Figure 3. The structure of a phospholipid found in the cell membrane
Figure 4. Integral and Peripheral membrane proteins with their
● Hydrophilic phosphate groups are found in the exterior locations; in relation to the cell membrane
Figure 5. Diagram depicting how the endomembrane system
works
Endoplasmic Reticulum (ER)
● Functions
o Protein Synthesis – the template for protein
and interior of the cell.
o Hydrophobic layer
▪ Because of this layer, the substances
can//cannot pass through the cell membrane
▪ Some substances are big and aren’t
permeable to the hydrophobic layer which is
why there is a need for a transport protein synthesis comes from the nucleus and the
o Cholesterol/ sterols are found interspersed structure of the ER, therefore interrelated to it.
between the phospholipid bilayers. o Lipid Synthesis – once synthesized, lipids are
o Sterols give the cell membrane fluidity; the incorporated in the endoplasmic membrane. If a
more fluid it is, the more cholesterol inside the cell is actively synthesizing lipids, the ER is very
cell membrane; it also determines the
permeability of the hydrophobic layer to
substances.
● Cell membrane proteins
o Integral Proteins
▪ Transverse the whole cell
responsible for the adhesion of one cell to
another.
OUTLINE
I. Introduction V. Physical Structure of the Cell
II. Organization of the Cell VI. Locomotion of the Cells
III. Basc Ingredients of the VII. References
Protoplasm
IV. Glycocalyx
I. ORGANIZATION OF THE CELL
● 2 Major parts:
o Nucleus
▪ Nuclear membrane – protect the nucleus from
the rest of the structures of the cytoplasm Figure 1. Types of Proteins
o Cytoplasm
▪ Cytoplasmic membrane – protects the
● Lipids
cytoplasm of the cell from the extracellular
o Phospholipids are the most abundant lipid count
environment
in the cell.
● Protoplasm – everything that makes up the cell
▪ Lipid bilayer – pattern/arrangement of
(cytoplasm + nucleus)
phospholipids.
o Sterols/ Cholesterols – interspersed within the
II. BASIC INGREDIENTS OF THE PROTOPLASM phospholipid bilayer. Sterols give a degree of
fluidity
● Water o Triglycerides or neutral fats – storage form of
o Principal fluid medium EXCEPT for fat cells lipids. This is another form of lipids aside from
o Comprises 70-85% those in the cell membrane, found in adipose
● Ions cells.
o Consists abundantly of sodium & potassium
o Important in chemical reactions and passage of ● Carbohydrates
electrical impulses o Mostly found in the cell membrane and is usually
● Proteins in contact with proteins (glycoproteins)
o Constitute 10-20% of cell mass o Functions of glycoproteins:
o Types: ▪ Receptors
▪ Structural Proteins – are stable and/or fixed. ▪ Attachment
These proteins give structure to the o Another form of carbohydrates aside from those
extracellular and intracellular part of the found in cell membranes would be the storage
human body (found outside and inside the cell) form (glycogen) found in the liver and muscles
▪ Intracellular Structural Proteins – are proteins
inside the cell that mostly maintain the shape III. GLYCOCALYX
of the cell and are also very important in ● Carbohydrates found on the surface of the cell
mitosis. Examples of intracellular proteins: membrane can be seen outside, mostly found in the GI
microtubule networks, spindles tract.
▪ Extracellular Structural Proteins – provides ● Functions of Glycocalyx:
structural scaffolding to surrounding cells. o Attachment of the cell to another (negative
Extracellular structural proteins: collagen, charge repels other objects)
elastic fibers (mostly found in connective o Facilitates the cell to cell interaction and
tissues) recognition
o Protects the cell from outside substances
▪ Functional proteins – could be motile or
adhere to membranous structures. It acts as
enzymes, catalysts of reactions, or those that IV. PHYSICAL STRUCTURE OF THE CELL
are used as passages or channels within the
● The cell is composed of highly organized intracellular
cell membrane. Also serves as identifying
organelles that are interrelated to each other
, ▪ Act as receptors, ligands, or secondary
Cell membrane messengers
● A very fluid bilayer that is thin, pliable, and elastic ▪ Serves as anchor for the cytoskeleton extra-
● Transport proteins are interspersed within the and intracellularly to make it stable
phospholipid bilayer (mostly made up of proteins in o Peripheral Proteins
terms of mass) ▪ Some are attached at the periphery of the
● The lipid bilayer is very permeable to: membrane while some are closely related
a. Oxygen with the integral proteins.
b. Carbon dioxide ▪ Primarily function as enzymes and
c. Alcohol controllers of transport.
Figure 2. The lipid bilayer and its components
Figure 3. The structure of a phospholipid found in the cell membrane
Figure 4. Integral and Peripheral membrane proteins with their
● Hydrophilic phosphate groups are found in the exterior locations; in relation to the cell membrane
Figure 5. Diagram depicting how the endomembrane system
works
Endoplasmic Reticulum (ER)
● Functions
o Protein Synthesis – the template for protein
and interior of the cell.
o Hydrophobic layer
▪ Because of this layer, the substances
can//cannot pass through the cell membrane
▪ Some substances are big and aren’t
permeable to the hydrophobic layer which is
why there is a need for a transport protein synthesis comes from the nucleus and the
o Cholesterol/ sterols are found interspersed structure of the ER, therefore interrelated to it.
between the phospholipid bilayers. o Lipid Synthesis – once synthesized, lipids are
o Sterols give the cell membrane fluidity; the incorporated in the endoplasmic membrane. If a
more fluid it is, the more cholesterol inside the cell is actively synthesizing lipids, the ER is very
cell membrane; it also determines the
permeability of the hydrophobic layer to
substances.
● Cell membrane proteins
o Integral Proteins
▪ Transverse the whole cell
