Cells and Organelles Flashcards
What causes Hutchinson-Gilford progeria?
A mutation in a gene that codes for the nuclear envelope.
What causes myoclonic epilepsy with ragged red fibres (MERF Syndrome)?
A mutation in the mitochondrial gene.
What causes Tay-Sachs disease?
A mutation in the gene coding an lysosomal enzyme.
What is a normal human cell size?
30 micrometers
What is a normal cell nucleus size?
3-10 micrometers
What is a normal peroxisome size?
0.5-1.5 micrometers
What is a normal bacteria size?
1 micrometer
What is a normal lysosome size?
80-800 nanometers
What is a normal virus size?
50 nanometers
What is a normal light microscope resolution?
200 nanometers
What is a normal electron miscroscope resolution?
0.2 nanometers
Give an example of a non-membrane bound organelle?
Ribosomes
Name X3 ways a prokaryote differs from a eukaryote.
1) single celled
2) chromosomes in a circular strand, no nucleus to house this
3) no membrane bound organelles
What is the cell theory?
That all living organisms are composed of cells, which arise through the division of pre-existing cells
What can you and can’t you see via light microscopy?
Up to the cellular level but not sub-cellular (e.g. no organelles, maybe nucleus).
What are the X2 types of electron microscope?
How do each of these work?
1) scanning = looks at cell surface only as electrons are scattered off of the surface due to a heavy metal coating (gold = Au)
2) transmission = electrons travel through the specimen and therefore can look inside the cell
What is a downside to electron microscopy?
It can only look inside dead cells due to requiring long and elaborate preparation
What are features specialised cells can have to overcome diffusion distance difficulties?
1) thin processes = large and thin cells in shape
2) giant multinucleate cells
3) gap junctions between cells
What is a benefit of an organelle being membrane bound?
It allows them to create specific conditions that they may require for optimal function such as differing pH’s
What are the X3 different types of proteins that make u0 the cytoskeleton?
Which is the thinnest and which is thickest?
1) actin = thinnest
2) intermediate filaments (IF’s)
3) microtubules = thickest
In what state is DNA in the nucleus during interphase?
Wound around his tone proteins as well as nom-his tone proteins as chromatin. It condenses into chromosomes during mitosis.
What are X3 structural elements to the nucleus?
1) nuclear envelope = phospholipid bi-layer for organelle regulation
2) nuclear pores = allow transport into and out of the cell
3) nucleolus = where rDNA is transcribed and ribosome subunits are assembled
What does the smooth ER do?
Synthesises lipids and steroids and packages them into vesicles before sending them to the Golgi.
What does the rough ER do?
Is studded with ribosomes which carry out translation (synthesis of proteins). These are also packaged into vesicles and sent to the Golgi.
