CPS103: The drug and the cell
Summary
1
,1. Characteristics of the Human cell
Human cells are typical eukaryotic cells, surrounded by a plasma membrane. In general, the
cells range from 1-100 m in size. Within tissue the cells are bound together by an
intracellular matrix filled with collagen.
1.1 All cell organelles and their properties.
For each organelle the following questions are answered below:
1. What is the function?
2. What is the structure?
3. Why is it needed?
4. What are typical proteins related to the organelle?
Nucleus (6 m)
What is the function?
The nucleus holds all of the genetic code of the cell, contained in DNA. It serves to protect
and regulate (via the Nuclear pores) the gene expression an DNA replication.
What is the structure?
Chromatin is a complex of proteins with DNA. The nuclear envelope is a protective layer
passable for water-soluble molecules/certain RNA strands/ribosome subunits. Nucleoplasm
is similar to cytoplasm. Nucleolus contains rDNA and it’s a ribosome creation site.
2
, Why is it needed?
The nucleus serves the important function of protecting DNA, the basis of the cell. It is
absolutely necessary for survival as it enables gene expression, cell division and repairs.
What are typical proteins?
• Chromatin: a complex of DNA and proteins.
• Nucleoporins: transport proteins with the structure of nuclear pores.
• Enzymes:
o Helicases – unwinds double stranded DNA
o Polymerases – create mRNA from DNA precursors
Nuclear Pores (0.2 m) and Nuclear Envelope
What is the function?
The nuclear envelope (NE) is a barrier layer that contains the nucleolus, chromatin and
nucleoplasm. It keeps the genetic material safe. The separation allows replication in the
nucleus to occur prior to nuclear division and to produce different types of RNA. A nuclear
pore (NP) is a miniscule opening through the NE. It regulates the import/export of
macromolecules such as proteins, mRNA, tRNA, ribosome subunits and viruses.
What is the structure?
See next page.
Why is it needed?
It protects the nucleolus (and genetic material) and regulates import/export.
What are typical proteins?
Nucleoporins and phospholipids.
Rough ER, smooth ER and Ribosomes (7 nm)
What is the function?
The rough ER has ribosomes attached to it; hence the name. It is adjacent to the nucleus
and is involved with production and modification of proteins. Proteins produced via the
rough ER have a specific destination
The smooth ER doesn’t have ribosomes attached to it. It is involved with the synthesis of
lipids and steroid hormones as well as detoxification.
Ribosomes consist of about 60% RNA and 40% protein. There are small and large ribosomal
subunits as well as free and membrane-bound ones. They are involved with translation.
3
Summary
1
,1. Characteristics of the Human cell
Human cells are typical eukaryotic cells, surrounded by a plasma membrane. In general, the
cells range from 1-100 m in size. Within tissue the cells are bound together by an
intracellular matrix filled with collagen.
1.1 All cell organelles and their properties.
For each organelle the following questions are answered below:
1. What is the function?
2. What is the structure?
3. Why is it needed?
4. What are typical proteins related to the organelle?
Nucleus (6 m)
What is the function?
The nucleus holds all of the genetic code of the cell, contained in DNA. It serves to protect
and regulate (via the Nuclear pores) the gene expression an DNA replication.
What is the structure?
Chromatin is a complex of proteins with DNA. The nuclear envelope is a protective layer
passable for water-soluble molecules/certain RNA strands/ribosome subunits. Nucleoplasm
is similar to cytoplasm. Nucleolus contains rDNA and it’s a ribosome creation site.
2
, Why is it needed?
The nucleus serves the important function of protecting DNA, the basis of the cell. It is
absolutely necessary for survival as it enables gene expression, cell division and repairs.
What are typical proteins?
• Chromatin: a complex of DNA and proteins.
• Nucleoporins: transport proteins with the structure of nuclear pores.
• Enzymes:
o Helicases – unwinds double stranded DNA
o Polymerases – create mRNA from DNA precursors
Nuclear Pores (0.2 m) and Nuclear Envelope
What is the function?
The nuclear envelope (NE) is a barrier layer that contains the nucleolus, chromatin and
nucleoplasm. It keeps the genetic material safe. The separation allows replication in the
nucleus to occur prior to nuclear division and to produce different types of RNA. A nuclear
pore (NP) is a miniscule opening through the NE. It regulates the import/export of
macromolecules such as proteins, mRNA, tRNA, ribosome subunits and viruses.
What is the structure?
See next page.
Why is it needed?
It protects the nucleolus (and genetic material) and regulates import/export.
What are typical proteins?
Nucleoporins and phospholipids.
Rough ER, smooth ER and Ribosomes (7 nm)
What is the function?
The rough ER has ribosomes attached to it; hence the name. It is adjacent to the nucleus
and is involved with production and modification of proteins. Proteins produced via the
rough ER have a specific destination
The smooth ER doesn’t have ribosomes attached to it. It is involved with the synthesis of
lipids and steroid hormones as well as detoxification.
Ribosomes consist of about 60% RNA and 40% protein. There are small and large ribosomal
subunits as well as free and membrane-bound ones. They are involved with translation.
3
