Things I Don't Know Part 2 Flashcards
Where can translation occur?
In the cytoplasm, or on the surface of the endoplasmic reticulum.
Describe what causes the neuronal disorder Lishencephaly.
A defect in the gene lis1, a regulator of dyenin.
What is the main role of dyenin?
Moves nuclei in humans and fungi.
Name the components of the endomembrane system.
- Endoplasmic reticulum
- Golgi
- Lysosomes
- Endosomes (late, early, recycling)
- Peroxisomes
- Lipid droplets
What is exocytosis?
The release of material into the extracellular space.
What are other names for the Biosynthetic pathway?
- Exocytic pathway
- Secretion pathway
Name the organelles/cellular compartments involved in endocytosis.
- Early endosomes
- Late endosomes
- Lysosomes
Give a function of lysosomes in specialised cells.
Participate in the secretion of hydrolases.
Describe the inner environment of lysosomes.
Acidic (pH 5.0)
What is pinocytosis?
The uptake of liquid into a cell.
What is phagocytosis?
The uptake of large particles, e.g. prokaryotes
Describe the ‘fast recycling pathway’.
1) Endocytic vesicles form at plasma membrane
2) Endocytic vesicles fuse with early endosome
3) Ligands and receptors separate
4) Receptors are recycled
Describe the ‘slow recycling pathway’.
1) Material is transported from the early to the recycling endosome
2) Material is transported back into the plasma membrane.
What are the roles of the lysosome?
- Receives material from the endocytic pathways
- Fuses with autophagosomes
Where are lipid droplets formed?
The smooth endoplasmic reticulum (ER)
What are v-SNAREs?
Proteins in transport vesicles that allow the vesicles to fuse with specific target membranes by recognising t-SNAREs on the membrane.
What do nuclear pores consist of?
What do they do?
Nuclear pores consist of nucleoporins (proteins).
They form a selective gate, allowing free passage of small molecules (e.g. ions), and restricting transport of larger proteins and complexes.
What is the nuclear lamina?
Interaction between the nuclear ropes and intermediate protein filaments.
In which organisms is the nuclear lamina found?
In animal cells only.
What does the nucleolus make?
Ribosomal subunits
Describe heterochromatin.
Densely-packed, transcriptionally inactive DNA form.
Describe euchromatin.
Loosely organised, transcriptionally active DNA form.
Name the enzyme that transcribes DNA into mRNA.
RNA polymerase II
What is the role of RNA polymerase I?
Makes up ribosomal RNA (rRNA).
