Samenvatting celbiologie
Les 5 en 6
Describe a signal transduction pathway.
Sequence of changes in a series of molecules
resulting in a response.
A steroid hormone binds to an intracellular receptor.
When it does, the resulting complex is able to do
which of the following?
Act as a transcription factor in the nucleus.
What is an example of signal amplifcation?
Activation of 100 molecules by a single signal
binding event.
, Les 6
Cell division
- In unicellular organisms, division of one cell reproduces the entire
organism.
- Multicellular organisms depend on cell division for:
Development from a fertilized cell
Growth
Repair/Renewal
- Cell division (cytokinesis) is an integral part of the cell cycle, the life
of a cell from formation to its own division.
Cellular Organization of the Genetic Material
- All the DNA in a cell constitutes the cell’s genome (nucleus vs
nucleoid).
- A genome can consist of a single DNA molecule (prokaryotic cells) or
a number of DNA molecules (eukaryotic cells).
- DNA molecules in a cell are packaged into chromosomes.
Chromosomes
- Every eukaryotic species has a characteristic number of
chromosomes in each cell nucleus.
- Somatic cells (nonreproductive cells) have two sets of chromosomes (2n).
- Gametes (reproductive cells: sperm and eggs) have half as many
chromosomes as somatic cells (n).
- Eukaryotic chromosomes consist of chromatin, a complex of DNA
and protein that condenses during cell division.
Mitosis is not the same as the cell cycle.
- Eukaryotic cell division consists of:
Mitosis, the division of the nucleus.
Cytokinesis, the division of the cytoplasm.
The cell cycle
The mitotic phase alternates with interphase in the cell cycle
- The cell cycle consists of:
Mitotic (M) phase (mitosis and cytokinesis).
Interphase (cell growth and copying of chromosomes in preparation
for cell division).
Les 5 en 6
Describe a signal transduction pathway.
Sequence of changes in a series of molecules
resulting in a response.
A steroid hormone binds to an intracellular receptor.
When it does, the resulting complex is able to do
which of the following?
Act as a transcription factor in the nucleus.
What is an example of signal amplifcation?
Activation of 100 molecules by a single signal
binding event.
, Les 6
Cell division
- In unicellular organisms, division of one cell reproduces the entire
organism.
- Multicellular organisms depend on cell division for:
Development from a fertilized cell
Growth
Repair/Renewal
- Cell division (cytokinesis) is an integral part of the cell cycle, the life
of a cell from formation to its own division.
Cellular Organization of the Genetic Material
- All the DNA in a cell constitutes the cell’s genome (nucleus vs
nucleoid).
- A genome can consist of a single DNA molecule (prokaryotic cells) or
a number of DNA molecules (eukaryotic cells).
- DNA molecules in a cell are packaged into chromosomes.
Chromosomes
- Every eukaryotic species has a characteristic number of
chromosomes in each cell nucleus.
- Somatic cells (nonreproductive cells) have two sets of chromosomes (2n).
- Gametes (reproductive cells: sperm and eggs) have half as many
chromosomes as somatic cells (n).
- Eukaryotic chromosomes consist of chromatin, a complex of DNA
and protein that condenses during cell division.
Mitosis is not the same as the cell cycle.
- Eukaryotic cell division consists of:
Mitosis, the division of the nucleus.
Cytokinesis, the division of the cytoplasm.
The cell cycle
The mitotic phase alternates with interphase in the cell cycle
- The cell cycle consists of:
Mitotic (M) phase (mitosis and cytokinesis).
Interphase (cell growth and copying of chromosomes in preparation
for cell division).
