14 Flashcards
How many cells are in our body?
37 Trillion
how many different cell types are in our body?
210
What are two diff microscopes that can be used with their magnification?
Light microscopy (2,000x)
Electron microscopy (>500,000 x)
What are the two main types of imaging techniques for cells?
Immunocytochemistry: using antibodies to pick up proteins in cell.
Immunohistochemistry: Using antibodies to identify cell structures within whole tissue cells
What are the two main forms of chromatins? and their characteristics?
Euchromatin: loosely packed so electron light so doesn’t show well on electron microscope –> transcribed
Heterochromatin: tightly packed electron dense so shows well on electron microscope
What is the function of the nucleolus?
The nucleolus makes ribosomal subunits from proteins and ribosomal RNA, also known as rRNA. It then sends the subunits out to the rest of the cell where they combine into complete ribosomes.
What diseases are linked with failure in structure of nucleus
Laminopathies ( Emery Dreifuss muscular dystrophy, hutchinson Gilford progeria syndrome)
What disease is linked with problems in the RER
Cystic fibrosis. CFTR synthesis happens in RER. CFTR protein is misfiled in the RER –> not translocated to PM.
What is the function of the smooth ER
Makes (Synthesis of) lipids and carbohydrates
Storage site for calcium (in muscle par example)
Detoxification- ER enzymes detoxify absorbed drugs toxins (liver and kidney have hgiher number of smooth than rough ER)
What is the difference between exocytosis an secretory vesicles
Exocytosis is constitutive secretion (not regulated by cell signalling)
e.g. Extra cellular matrix proteins by fibroblasts
Secretory vesicles-regulated by cellular signals e.g. Insulin-b cells in islets of Langerhans
What diseases are linked with lysosomal storage deficiencies=
Tay Sachs. Failure to break down gangliosides (lipids) so cell is clogged up –> dysfunctional.
Lysosomes function
Originate at Golgi
Contain digestive enzymes
Defense against disease (bacteria engulfed by macrophage are then taken up by lysosomes
Autophagy-cleanup of cell organelles (bc organelles have limited life expectancy)
Autolysis after cell death
Peroxisome function
originate at rough ER
metabolism of fatty acids (lipids)
detoxifying (contains enzymes that break down free radicals from normal metabolic processes, H2O2, alcohol)
Liver and Kidney
What diseases are linked to peroxisome deficiencies?
Leukodystrophies (Zellweger syndrome –> accumulate high levels of long chain fatty acids
What are some mitochondrial diseases
mitochondrial myopathies
What are the 3 key types of skeletal components of the cell with their sizes
Microfilament (3-6 nM)
Intermediate filaments (10 nM)
Microtubules (20-25 nM)
What are some diseases linked with gamma actin mutation
congenital deafness
What are some diseases linked with muscle actin mutation
myopathies
What are some diseases linked with intermediate filament mutation
EB, laminopathies
characteristics of Microtubules
cell scaffold
tracks for movement of cell organelles and vesicles (motors)
mitotic spindle fibres
cilia and flagella – locomotion
Drug targets - eg taxane anti- cancer drugs, stop cell division
characteristics of microfilaments
actin proteins polymerize in all cells-cell movement
cell cytoskeleton – control cell shape (stress fibers)
cell movements with myosin (e.g. cytokinesis)
cell organelle and vesicle transport
Actin can polymerize with myosin to allow cell movement and migration
Actin filaments act as highways in the cell for organelles and vesicles
alpha actin thin filaments with myosin in muscle movement
Actin filaments are important for cell division. At cytokinesis, actin ring forms around the cell to constrict the two daughter cells.
characteristics of intermediate filaments
Intermediate filaments, 10 nm, e.g. keratins in skin and hair, neurofilaments, lamins in nuclear envelope, muscle desmin
Intermediate in size between microfilaments (3-6 nM) & Microtubules (20-25nM)
Main role is to provide cell with tensile strength
Diseases e.g. keratin mutations in congenital epidermal blistering diseases – e.g. Epidermalysis Bullosa, Laminopathies
