Cells and organelles Flashcards
what constitutes a cell?
cells consist of various organelles and a membrane
what are the sizes of cells found in the body?
typical cell - 25µm
nerve cell - 10cm
muscle cells are bigger
what is the function of the nucleus?
contains the majority of the cell’s genetic material
what is the function of the nucleolus
site of synthesis of ribosomal subunits
what is the function of the nuclear envelope
keeps nucleoplasm separate from cytoplasm
what is the function of the mitochondrion
production of ATP
what is the function of the RER
synthesis and export of proteins and glycoproteins
what is the function of the SER
production of hormones and lipids
what is the function of the ribosome
protein synthesis
what is the function of the golgi apparatus
- modifying, sorting and packaging proteins
- transport of lipids
- synthesis of lysosomes
what is the function of the secretory granule
where neuropeptides/hormones are packaged and stored for secretion
what is the function of the plasma membrane
regulation of which molecules can exit/enter the cell
what is the function of the cytoskeletal components
important structural framework for the movement of organelles around the cytoplasm
what are the predominant types of molecules found in a cell?
- soluble proteins
- ions
- sugars
- nucleotides
- amino acids
- mRNA
- tRNA
- lipids
- peptides
(all dissolved in the cytoplasm)
define the essential characteristics of prokaryotic cells
- no membrane bound organelles
- may have photosynthetic pigments
- may have flagella for locomotion or pili for adhesion
- come in multiple shapes
describe the multiple shapes that prokaryotic cells can come in
- cocci: round
- bacilli: rods
- spirilla: helical cells
define the essential characteristics of eukaryotic cells
- membrane bound organelles, resulting in a higher degree of organisation
- no flagella/pilli
how important is the movement of molecules and organelles within cells, and of cells themselves?
essential
what is cancer?
a disorder of cell division
what mutations can cause cancer?
- switch on of oncogenes
- switch off of tumour suppressor genes
- loss of correction mechanism on DNA copying
- loss of control keeping cell within tissue boundaries (metastasis)
what helps cancer develop?
- ability to evade body defence mechanisms
- ability to recruit blood vessels to growing tumour
- ability to migrate into blood stream/lymph vessels
