CYTO311: CYTOGENETICS
WEEK 3: CELLS
CELLS PLASMA MEMBRANE
• All cells are surrounded by a plasma
CELLS membrane, a covering that defines cell
- Cells are highly varied and highly organized boundary
structures • The plasma membrane actively controls the
- Their forms and functions are dependent on movement of materials in and out of the
the genetic expression by each cell type cell
- Bone, blood, nerve and muscle cells are
somatic cells, also called as body cells GLYCOCALYX OR CELL COAT
• Most animal cells have glycocalyx or cell
Somatic cells have two copies of the genome coat
and are said to be diploid • The glycocalyx provides biochemical identity
at the surface of cells, and the components
Sperm and egg cells have only one copy of the of the coat that establish cellular identity are
genome and are said to be haploid under genetic control.
PROKARYOTES VS. EUKARYOTES NUCLEUS
- is a membrane bound structure that houses
PROKARYOTES the DNA, which is complex with protein into
- lack nucleus as opposed to the nucleated thin fibers.
cells of the eukaryotes
- Specialized organelles are also present in CHROMATIN
eukaryotic cells. - During the non-divisional phases of the cell
cycle, the fibers are uncoiled and dispersed
CHEMICAL CONSTITUENT OF THE CELL into chromatin.
• Cells are composed of macromolecules CHROMOSOMES
important in biological processes. The major - During mitosis and meiosis, chromatin fibers
groups of these substances are: coil and condense into chromosomes.
carbohydrates, lipids, proteins and nucleic
acids. NUCLEOLUS
- present inside the nucleus, is where
Carbohydrates- provide energy ribosomal RNA is synthesized.
Lipids form membranes and hormones - provide • In prokaryotes, the genetic material is
insulation and store energy compacted into an unenclosed region called
the nucleoid.
Proteins - have many diverse functions in the
body, and are important in blood clotting, nerve • The DNA in prokaryotes is not associated with
transmission, muscle contraction, and immunity, proteins as is the case with eukaryotes.
while others serve and catalysts
CYTOPLASM
Most important in genetics are the nucleic acids - The remainder of the cell within the plasma
DNA and RNA membrane, excluding the nucleus, is called as
the cytoplasm and includes a variety of
organelles.
ENDOPLASMIC RETICULUM
- The endoplasmic reticulum appears smooth
in places where it serves as site for synthesis
of fatty acids and phospholipids, and in
other places, appears rough as it is studded
with ribosomes
RIBOSOMES
- Ribosomes are sites of protein synthesis,
guided by the information contained in the
mRNA.
1
M.M.
WEEK 3: CELLS
CELLS PLASMA MEMBRANE
• All cells are surrounded by a plasma
CELLS membrane, a covering that defines cell
- Cells are highly varied and highly organized boundary
structures • The plasma membrane actively controls the
- Their forms and functions are dependent on movement of materials in and out of the
the genetic expression by each cell type cell
- Bone, blood, nerve and muscle cells are
somatic cells, also called as body cells GLYCOCALYX OR CELL COAT
• Most animal cells have glycocalyx or cell
Somatic cells have two copies of the genome coat
and are said to be diploid • The glycocalyx provides biochemical identity
at the surface of cells, and the components
Sperm and egg cells have only one copy of the of the coat that establish cellular identity are
genome and are said to be haploid under genetic control.
PROKARYOTES VS. EUKARYOTES NUCLEUS
- is a membrane bound structure that houses
PROKARYOTES the DNA, which is complex with protein into
- lack nucleus as opposed to the nucleated thin fibers.
cells of the eukaryotes
- Specialized organelles are also present in CHROMATIN
eukaryotic cells. - During the non-divisional phases of the cell
cycle, the fibers are uncoiled and dispersed
CHEMICAL CONSTITUENT OF THE CELL into chromatin.
• Cells are composed of macromolecules CHROMOSOMES
important in biological processes. The major - During mitosis and meiosis, chromatin fibers
groups of these substances are: coil and condense into chromosomes.
carbohydrates, lipids, proteins and nucleic
acids. NUCLEOLUS
- present inside the nucleus, is where
Carbohydrates- provide energy ribosomal RNA is synthesized.
Lipids form membranes and hormones - provide • In prokaryotes, the genetic material is
insulation and store energy compacted into an unenclosed region called
the nucleoid.
Proteins - have many diverse functions in the
body, and are important in blood clotting, nerve • The DNA in prokaryotes is not associated with
transmission, muscle contraction, and immunity, proteins as is the case with eukaryotes.
while others serve and catalysts
CYTOPLASM
Most important in genetics are the nucleic acids - The remainder of the cell within the plasma
DNA and RNA membrane, excluding the nucleus, is called as
the cytoplasm and includes a variety of
organelles.
ENDOPLASMIC RETICULUM
- The endoplasmic reticulum appears smooth
in places where it serves as site for synthesis
of fatty acids and phospholipids, and in
other places, appears rough as it is studded
with ribosomes
RIBOSOMES
- Ribosomes are sites of protein synthesis,
guided by the information contained in the
mRNA.
1
M.M.
