BIOCHEMISTRY LECTURE / FIRST SEMESTER
THE CELLS AND ITS CHEMISTRY
LEARNING OBJECTIVES
I. Define Cell A SCALE OF VISIBILITY
II. Identify the parts and understand the functions
of each part
III. Identify the constituents of a cell
IV. Describe how buffers function to maintain a
constant physiological pH
WHAT IS CELLS?
Cells are the structural and functional units of all living
organisms
Smallest organisms consist of single cells.
Cells arise only by division of a previously existing cell.
Cells vary in size and shapes. TWO MAJOR CLASSES OF CELL
CELL THEORY
Cell theory is a scientific theory first formulated in the mid-
nineteenth century, that living organisms are made up of
cells, that they are the basic structural/organizational unit of
all organisms, and that all cells come from pre-existing cells
Cells are the basic unit of structure in all organisms and also
the basic unit of reproduction.
The three tenets to the cell theory are as described below:
All organism (living things) are made up of one or more
cells
Matthias Schleiden – plants are made up of cells
Theodor Schwann – animals are made up of cells
Rudolf Virchow stated that “Cells arise from pre-existing
cells.”
CELL REQUIREMENTS
GENETIC MATERIAL
- Single circular molecule of DNA in prokaryotes
- Double helix located in nucleus in eukaryotes
CYTOPLASM
- Fills cell interior (sugars, amino acids, proteins,
organelles)
PLASMA MEMBRANE
- Encloses the cell
CELL SIZES
Most cells are relatively small because as
size increases, volume increases much more
rapidly.
Cell size and shape are related cell function SOPHIA NICOLE POSERIO MACAM
UNIVERSIDAD DE MANILA
BSN- 14
, BIOCHEMISTRY LECTURE / FIRST SEMESTER
THE CELLS AND ITS CHEMISTRY
ANIMAL CELL
A lipid bilayer forms spontaneously whenever a
collection of phospholipids is placed in water
The interior of the lipid bilayer is completely nonpolar
- no water – soluble molecules can freely cross
PLANT CELL through it
- cholesterol is also found in the interior
→ it affects the fluid nature of the membrane
→ its accumulation in the walls of blood vessels can
cause plaques
→ plaques lead to cardiovascular disease
Another major component of the membrane is a collection of
membrane proteins
- some proteins form channels that span the
membrane
→ these are called transmembrane proteins
- other proteins are integrated into the structure of the
membrane
→ for example, cell surface proteins are attached to
the outer surface of the membrane and act as markers
THE PLASMA MEMBRANE PROTEINS ARE EMBEDDED WITHIN
The plasma membrane is conceptualized by the THE LIPID BILAYER
fluid mosaic model
- a sheet of lipids with embedded proteins
→ the lipid layer forms the foundation of the
membrane
→ the fat molecules comprising the lipid layers
are called phospholipids
A phospholipids has a
polar head and two
non-polar tails.
The polar region
contains a phosphate
chemical group and is
water- soluble.
The non-polar region
is comprised of fatty
acids and is water-
SOPHIA NICOLE POSERIO MACAM
insoluble. UNIVERSIDAD DE MANILA
BSN- 14
THE CELLS AND ITS CHEMISTRY
LEARNING OBJECTIVES
I. Define Cell A SCALE OF VISIBILITY
II. Identify the parts and understand the functions
of each part
III. Identify the constituents of a cell
IV. Describe how buffers function to maintain a
constant physiological pH
WHAT IS CELLS?
Cells are the structural and functional units of all living
organisms
Smallest organisms consist of single cells.
Cells arise only by division of a previously existing cell.
Cells vary in size and shapes. TWO MAJOR CLASSES OF CELL
CELL THEORY
Cell theory is a scientific theory first formulated in the mid-
nineteenth century, that living organisms are made up of
cells, that they are the basic structural/organizational unit of
all organisms, and that all cells come from pre-existing cells
Cells are the basic unit of structure in all organisms and also
the basic unit of reproduction.
The three tenets to the cell theory are as described below:
All organism (living things) are made up of one or more
cells
Matthias Schleiden – plants are made up of cells
Theodor Schwann – animals are made up of cells
Rudolf Virchow stated that “Cells arise from pre-existing
cells.”
CELL REQUIREMENTS
GENETIC MATERIAL
- Single circular molecule of DNA in prokaryotes
- Double helix located in nucleus in eukaryotes
CYTOPLASM
- Fills cell interior (sugars, amino acids, proteins,
organelles)
PLASMA MEMBRANE
- Encloses the cell
CELL SIZES
Most cells are relatively small because as
size increases, volume increases much more
rapidly.
Cell size and shape are related cell function SOPHIA NICOLE POSERIO MACAM
UNIVERSIDAD DE MANILA
BSN- 14
, BIOCHEMISTRY LECTURE / FIRST SEMESTER
THE CELLS AND ITS CHEMISTRY
ANIMAL CELL
A lipid bilayer forms spontaneously whenever a
collection of phospholipids is placed in water
The interior of the lipid bilayer is completely nonpolar
- no water – soluble molecules can freely cross
PLANT CELL through it
- cholesterol is also found in the interior
→ it affects the fluid nature of the membrane
→ its accumulation in the walls of blood vessels can
cause plaques
→ plaques lead to cardiovascular disease
Another major component of the membrane is a collection of
membrane proteins
- some proteins form channels that span the
membrane
→ these are called transmembrane proteins
- other proteins are integrated into the structure of the
membrane
→ for example, cell surface proteins are attached to
the outer surface of the membrane and act as markers
THE PLASMA MEMBRANE PROTEINS ARE EMBEDDED WITHIN
The plasma membrane is conceptualized by the THE LIPID BILAYER
fluid mosaic model
- a sheet of lipids with embedded proteins
→ the lipid layer forms the foundation of the
membrane
→ the fat molecules comprising the lipid layers
are called phospholipids
A phospholipids has a
polar head and two
non-polar tails.
The polar region
contains a phosphate
chemical group and is
water- soluble.
The non-polar region
is comprised of fatty
acids and is water-
SOPHIA NICOLE POSERIO MACAM
insoluble. UNIVERSIDAD DE MANILA
BSN- 14
