cell biology + neuroscience
Created @December 6, 2022 1:00 PM
Reviewed
Cell types and subcellular structures
describe the concept of the cell
defining features = membrane, genetic info, metabolism
cell theory = new cells come from existing cells dividing, smallest basic
unit of life, all living organisms one or more cells
classify different types of cells: prokaryotes, eukaryotes, bacteria, archaea,
fungi, plants, animals
prokaryotes - bacteria (including cyanobacteria) and archaea (extreme
environments eg. halophiles high salt, thermoacidophiles hot/sulfur) =
unicellular, no nucleus
eukaryotes - plants (including algae), animals, fungi (including yeast),
protozoa) = can be multicellular, nucleus
outline the basic organisation of eukaryotic cells and give a brief description
of the major eukaryotic cell organelles and the specialised cellular processes
that take place in them: plasma membrane, nucleus, rough and smooth
endoplasmic reticulum, Golgi apparatus, lysosomes and peroxisomes,
mitochondria and chloroplasts, cytosol, cytoskeleton
plasma membrane
structure - amphipathic phospholipid bilayer, transmembrane proteins,
cholesterol for fluidity, dynamic lipid rafts
roles - communication, barrier, import/export, cell shape, electrical
capacitor
nucleus
cell biology + neuroscience 1
, structure - pored, double-layer lipid membrane (aka envelope) + nucleolus
(location of ribosome and SRP synthesis, gene regulatory protein
capture/detention) + nucleoplasm
roles - holds genetic info in form of DNA as chromosomes/histones/gene
regulatory proteins, site of RNA synthesis/processing
endoplasmic reticulum
structure - interconnected vesicles (cisternae) consistent with nuclear
membrane
a. rough - ribosomes embedded in membrane = site of secreted and
transmembrane protein synthesis, stained by nissl, abundant in secretory
cells
b. smooth - lipid/cholesterol/steroid hormones synthesis, detox and release
of glucose (in liver)
golgi apparatus
structure - flattened membrane bound stack of vesicles
roles - proteins modified and packaged into vesicles for export
(secretion/transmembrane embedding)
lysosomes (animal cells only)
structure - membrane bound vesicles, acidic pH (4.5) optimum for
degradative hydrolytic enzymes
roles - degrade unwanted proteins/membrane/organelles/pathogens (act
as macrophages)
perioxisomes
roles - oxidative degradation of non proteins: fatty acids (into precursors
and H2O2 - neutralised by catalase) and toxins eg. ethanol
mitochondria
structure - double membrane, inner membranefolded into cristae with
more transmembrane proteins embedded, 1um thick, circular DNA
(alternative genetic code to nuclDNA) and ribosomes in matrix, make up
up to 25% cytoplasm
cell biology + neuroscience 2
, roles - respiration (oxidative phosphorylation/TCA cycle), heat production,
apoptosis, Ca 2+ regulation/storage
chloroplasts
similar to mitochondria but only in plants - photosynthesis
cytoskeleton
structure - protein fibre network = intermediate filaments + microtubules +
actin/micro filaments
roles - structure/shape, movement within cell and of whole cell, cell
division, transport in cell
cytosol
structure - aqueous solution, set pH 7.2 and ion conc
contains - ions, ribosomes, tRNAs, transport proteins, enzymes,
messengers, glycogen, inclusion bodies
Cells in their environment
speculate on the origins of cellular life forms on earth
timeline: ancestral prokaryotes 4bill yrs ago > 1.5bill yrs bacteria, archaea
(no organelles, only one cell compartment, extreme environments and
energy sources, fast inaccurate reproduction, variety and specialisations
eg. flagella) > anaerobic ancestral eukaryote
origins of last universal common ancestor: chemicals + minerals (HCHO,
HCN, cyanamide, glyceraldehyde, PO4) acting as catalysts + high temp >
formed simple RNA > increased complexity and ribozymes for self
replication > stabler DNA to pass genetic info down generations >
spontaneous lipid bilayers, ribosomes to make proteins
endosymbiotic theory - bacteria engulfed by ancestral eukaryotic cell =
mitochondria (chloroplast in plants), bacteria protected and in return
eukaryote gets energy
chlorophyll photosynthesis: type 1 (green sulfur and heliobacteria), 2
(purple/green filamentous), cyanobacteria
explain the concept of cellular specialisation in the context of multicellularity
cell biology + neuroscience 3
, within multicellular organism, specialisation = different roles of different
cells
‘ex ovo omnia’ - everything from egg
colonial green alga = two cell types, differentiated somatic and germ
provide an overview of cellular and subcellular pathogens
cellular - bacteria (cholera, MRSA, cyanobacteria), fungi (candida,
athletes foot, cryptococcus, valley fever), protozoa (eg. malaria,
toxoplasmosis, giardiasis) (not archaea)
subcellular - virus = DNA/RNA + protein coat (sometimes lipid envelope) -
require host cell to reproduce (outside = virion), need electronmicroscope
to see, can lie dormant (herpes, varicella) or be retro/lenti (HIV)
protozoa = single cell eukaryotes, roles in motility/predation
Cytoskeleton
the terms microtubule, microfilament, intermediate filament
microtubule - 25nm hollow tubes
transport within cell, mitotic spindle, cilia
IF - 10nm filaments in bundles through cell
cytoplasmic = vimetin (connective, muscle, glia), neurofilaments
(nerves), keratins (epithelia, a helices coiled coil
dimers>tetramers>eight in filament, mutations = EB blisters)
or nuclear (nuclear lamins, in all animals)
microfilaments - 7nm coils
movement and shape of cell (eg. microvilli), force, cell division
the structure and polymerisation of actin and the function of myosin
actin structure = 375 AAs, 55kDa monomer with 2 domains, g globular,
binds ATP, fibres near membrane, all eukaryotes, most abundant protein
mutations = muscular dystrophy, haemolytic anemia
cell biology + neuroscience 4
Created @December 6, 2022 1:00 PM
Reviewed
Cell types and subcellular structures
describe the concept of the cell
defining features = membrane, genetic info, metabolism
cell theory = new cells come from existing cells dividing, smallest basic
unit of life, all living organisms one or more cells
classify different types of cells: prokaryotes, eukaryotes, bacteria, archaea,
fungi, plants, animals
prokaryotes - bacteria (including cyanobacteria) and archaea (extreme
environments eg. halophiles high salt, thermoacidophiles hot/sulfur) =
unicellular, no nucleus
eukaryotes - plants (including algae), animals, fungi (including yeast),
protozoa) = can be multicellular, nucleus
outline the basic organisation of eukaryotic cells and give a brief description
of the major eukaryotic cell organelles and the specialised cellular processes
that take place in them: plasma membrane, nucleus, rough and smooth
endoplasmic reticulum, Golgi apparatus, lysosomes and peroxisomes,
mitochondria and chloroplasts, cytosol, cytoskeleton
plasma membrane
structure - amphipathic phospholipid bilayer, transmembrane proteins,
cholesterol for fluidity, dynamic lipid rafts
roles - communication, barrier, import/export, cell shape, electrical
capacitor
nucleus
cell biology + neuroscience 1
, structure - pored, double-layer lipid membrane (aka envelope) + nucleolus
(location of ribosome and SRP synthesis, gene regulatory protein
capture/detention) + nucleoplasm
roles - holds genetic info in form of DNA as chromosomes/histones/gene
regulatory proteins, site of RNA synthesis/processing
endoplasmic reticulum
structure - interconnected vesicles (cisternae) consistent with nuclear
membrane
a. rough - ribosomes embedded in membrane = site of secreted and
transmembrane protein synthesis, stained by nissl, abundant in secretory
cells
b. smooth - lipid/cholesterol/steroid hormones synthesis, detox and release
of glucose (in liver)
golgi apparatus
structure - flattened membrane bound stack of vesicles
roles - proteins modified and packaged into vesicles for export
(secretion/transmembrane embedding)
lysosomes (animal cells only)
structure - membrane bound vesicles, acidic pH (4.5) optimum for
degradative hydrolytic enzymes
roles - degrade unwanted proteins/membrane/organelles/pathogens (act
as macrophages)
perioxisomes
roles - oxidative degradation of non proteins: fatty acids (into precursors
and H2O2 - neutralised by catalase) and toxins eg. ethanol
mitochondria
structure - double membrane, inner membranefolded into cristae with
more transmembrane proteins embedded, 1um thick, circular DNA
(alternative genetic code to nuclDNA) and ribosomes in matrix, make up
up to 25% cytoplasm
cell biology + neuroscience 2
, roles - respiration (oxidative phosphorylation/TCA cycle), heat production,
apoptosis, Ca 2+ regulation/storage
chloroplasts
similar to mitochondria but only in plants - photosynthesis
cytoskeleton
structure - protein fibre network = intermediate filaments + microtubules +
actin/micro filaments
roles - structure/shape, movement within cell and of whole cell, cell
division, transport in cell
cytosol
structure - aqueous solution, set pH 7.2 and ion conc
contains - ions, ribosomes, tRNAs, transport proteins, enzymes,
messengers, glycogen, inclusion bodies
Cells in their environment
speculate on the origins of cellular life forms on earth
timeline: ancestral prokaryotes 4bill yrs ago > 1.5bill yrs bacteria, archaea
(no organelles, only one cell compartment, extreme environments and
energy sources, fast inaccurate reproduction, variety and specialisations
eg. flagella) > anaerobic ancestral eukaryote
origins of last universal common ancestor: chemicals + minerals (HCHO,
HCN, cyanamide, glyceraldehyde, PO4) acting as catalysts + high temp >
formed simple RNA > increased complexity and ribozymes for self
replication > stabler DNA to pass genetic info down generations >
spontaneous lipid bilayers, ribosomes to make proteins
endosymbiotic theory - bacteria engulfed by ancestral eukaryotic cell =
mitochondria (chloroplast in plants), bacteria protected and in return
eukaryote gets energy
chlorophyll photosynthesis: type 1 (green sulfur and heliobacteria), 2
(purple/green filamentous), cyanobacteria
explain the concept of cellular specialisation in the context of multicellularity
cell biology + neuroscience 3
, within multicellular organism, specialisation = different roles of different
cells
‘ex ovo omnia’ - everything from egg
colonial green alga = two cell types, differentiated somatic and germ
provide an overview of cellular and subcellular pathogens
cellular - bacteria (cholera, MRSA, cyanobacteria), fungi (candida,
athletes foot, cryptococcus, valley fever), protozoa (eg. malaria,
toxoplasmosis, giardiasis) (not archaea)
subcellular - virus = DNA/RNA + protein coat (sometimes lipid envelope) -
require host cell to reproduce (outside = virion), need electronmicroscope
to see, can lie dormant (herpes, varicella) or be retro/lenti (HIV)
protozoa = single cell eukaryotes, roles in motility/predation
Cytoskeleton
the terms microtubule, microfilament, intermediate filament
microtubule - 25nm hollow tubes
transport within cell, mitotic spindle, cilia
IF - 10nm filaments in bundles through cell
cytoplasmic = vimetin (connective, muscle, glia), neurofilaments
(nerves), keratins (epithelia, a helices coiled coil
dimers>tetramers>eight in filament, mutations = EB blisters)
or nuclear (nuclear lamins, in all animals)
microfilaments - 7nm coils
movement and shape of cell (eg. microvilli), force, cell division
the structure and polymerisation of actin and the function of myosin
actin structure = 375 AAs, 55kDa monomer with 2 domains, g globular,
binds ATP, fibres near membrane, all eukaryotes, most abundant protein
mutations = muscular dystrophy, haemolytic anemia
cell biology + neuroscience 4
