Week 1 Cells and Organelles Flashcards
What is the function of carbohydrates?
It exists outside of bilayer in charge of cell recognition, especially during embryogenesis, glycocalyx (carb type) that covers cell membranes of bacteria, endothelial cells, cancer cells
What is the nuclear laminas formed from??
Intermediate filaments (keratin, lamins) –> strength)
What is the nucleus?
Double membrane that separates cytoplasm as nucleoplasm. Outer membrane is continuous with ER , inner membrane supported by nuclear lamina (movement happens in pores)
What is the function of smooth ER?
Lipid synthesis, calcium storage, steroid hormone synthesis (hepatocyte, leydig cell)
What is the function of the rough ER
Ribosome synthesis for proteins used outside the cell (plasma cell), immunoglobulin production
What is the function of cytochrome C in mitochondria?
Cell apoptosis
What is the function of golgi apparatus?
Protein modification. It undergoes enzymatic modifications for specific destination (mannose-6-phosphate marks protein headed for lysosome)
What is the structure and function of mitochondria?
A site of ATP production, integral for development, has 4 compartments: outer, inner membranes, matrix, intermembrane space
(cell with loads of mitochondria: ovum)
What are endosomes?
They have the early and late phases, and form lysosomes for degradation of molecules. This process involves M6P. (They either leave the cell as proteins/ lysosomes)
What are peroxisomes?
They are oxidases, catalyses, used for detoxification, biosynthesis of bile acid)
What are lipid rafts?
Compartmentalise cellular processes, involve in signalling
What are the different types of junctions?
GAP, tight, adherens, desmosomes, hemidesmosomes, focal adhesion
What types of junctions have actin cytoskeletons?
GAP, tight, adherens, focal adhesion
What are the cytoskeletons of desmosome and hemidesmosomes?
Intermediate filaments.
What are the functions of GAP?
Metabolic and electrical coupling (cardiac tissue)
What are the functions of tight junctions?
Forming barriers, selective permeability, cell polarity
What are the functions of adherens junctions?
Tissue integrity, contractility, motility
What are the functions of desmosomes?
Strong adhesion, resist chemical stress
What are the functions of hemidesmosomes?
Cell anchorage
What are the functions of focal adhesions?
Cell anchorage, mechanical and biochemical signalling
What is the function of cytoskeletons?
Support fragile plasa membrane, organise cell structure, resist mechanical stress, transports intracellular cargo, facilitates movements of organelles (i.e. for cell division)
What are the potential components of cytoskeletons?
- Intermediate filaments (keratin): twists into strong rope-like structures, high tensile strength, withstand pressure and stretching
- Microtubules (tubilin): dynamic cylindrical tubes that shrink and grow
- Microfilaments (actin, myosin): Cell projections (microvilli, stereocilia (long microvilli)
What is a lysosomal disorder?
Tay Sachs (build up of lipids)
What is a disorder of mitochondria?
Mitochondrial cytopathies
What is a microtubule (dynein) disorder?
Kartagener syndrome (immotile cilia, infertility in men)
What is a result of faulty gap junctions (mutation in Cx26)
Hearing loss
What is a mutation in IF/ hemidesmosomes?
Epidermolysis bullosa (fragile skin)
What are lamellipodia and filopodia?
Microspikes made from actin (cross linked), helpful in migrating cells
