session 3-cell ultrastructure and organelles Flashcards
what is the limit of resolution for an electron microscope?
-0.002nm
what is an endosome, peroxisome and cytosol?
- endosome=membrane bound. assists in transport pathway from plasma membrane to lysosome
- peroxisome=small organelle in cytoplasm which contains catalase and oxidases
- cytosol=aqueous part of cytoplasm
in terms of the phospholipid bilayer, what does amphipathic mean?
having both hydrophilic and phobic parts
what is the limit of resolution for light microscopes?
-0.2um
what is the glycocalyx?
cell ‘coat’ made up of oligosaccharides (a couple of monosaccharides) and polysaccharide side chains on outside of plasma membrane-side chains give cell SPECIFICITY
give 3 functions of the plasma membrane (plasmalemma)
- selective permeability
- exo/endocytosis
- signalling
- transport of materials
what is the role of the nucleus?
- stored cells DNA
- CO ORDINATES cell activities-metabolism,mitosis, protein synthesis
- contains chromatin
what is chromatin?
-unstructured DNA that will organise to form chromosomes in mitosis
what is the nuclear envelope attached to?
-a network of tubules (AKA endoplasmic reticulum)
what does the nucleolus synthesise?
ribosomes
name 3 places the smooth ER is found
liver, mammary glands, ovaries/testes
when vesicles bud off from the RER to be moved to the golgi, what face do they attach to?
-cis face of golgi (convex side) then to concave (trans) side
what is the function of the golgi?
-modify, package,sort and concentrate proteins
what happens to some vesicles?
become lysosomes
where are lysosomes generated?
golgi
what do you call lysosomes that have digested their contents but contain indigestible remnants?
residual bodies
what is produced in peroxisomes?
-H2O2
what enzyme uses h2o2 to oxidise things such as phenols, formaldehyde and alcohol?
catalase
what are the 2 main substrates of ATP production in the mitochondria?
glucose and fatty acids
which 2 places would you find many mitochondria?
- liver
- skeletal muscle cells
in terms of mitochondria, what does female lineage mean?
-inheriting all mitochondria from mother
name the 3 types of cytoskeleton (maintains or changes cell shape)
-microfilaments, microtubules and intermediate filaments
give 3 roles of the cytoskeleton
- supports plasma membrane and organelles
- helps constituents move
- helps muscles contract
what is the diameter of microfilaments?
5nm
what are microfilaments made up of?
-2 strings of actin twisted together (associated with ATP)
what is the diameter of intermediate filaments?
10nm
where would you find intermediate filaments?
nerves and some epithelia-form tough network
what are microtubules made up of?
-13 alpha and beta subunits form wall of hollow microtubules
where are microtubules found?
-near structures that move e.g. nerve fibres, mitotic spindle, cores of cilia and flagella
Can mitochondria divide on their own because they have their own genetic info?
Yes
What is the role of the nucleolus?
Make rRNA
