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Biology - Coggle Diagram
Biology
Gram staining
invented by Hans Christian Gram in 1882
procedure
a group of cells is being applied a crystal violet dye
then iodine
after it's washed with alcohol
in the end safranin dye is applied
two types of cells
Gram positive
have a outer thck cell wall and one cell membrane
the crystal violet stays on the cell wall and doesn't get washed away
gram negative
have two cell membrane and between one thin cell wall
the crystal violet it's harder to get to the cell wall so it washes off more easily
so they'll be dyed by just the safranin
more resistant to antibodies for the double cell membrane
can gain resistance to antibodies more easily
some cells don't responde as intended
acid fast cells
appear purple but aren't similar to Gram positive
Gram-variable cell
show a mix of pink and purple stain
Synapse
it's the junction between neurons an the next cell
types of connection
sensory receptor cells
receive sensory stimulus
other neurons
passes the stimulus
it's in the brain and spinal cord
interneurons
effector cells
it's the final neuron and sends the signal to a cell of the body, like muscle cells
the passage of the stimulus from start to end it's called a reflex arc
the nerve impulse reaches the axon terminal
calsium ions enter into the cell through channels
vescicles with neurotransmitter inside migrate to the membrane and release the chemical to the synaptic cleft by exocytosis
the synaptic cleft is the space between the two cells and it's 20nm wide
the neurotransmitters bind with the receptor in the post-synaptic membrane
sodium ion channels are triggered and sodium ions enter into the membrane
the action potential is then propagated along the cell
the neurotransmitters are broken down in the synaptic cleft and removed after
if there aren't enough neurotransmitters, the channles won't open up
the neurotransmitters are broken down and restored by the potassium channels
types of neurotransmitters
exciting
excites the dendrites receptors
Acetylcholine
most common
synapses who uses it are called cholinergic
in muscles
inhibiting
inhbits the post synaptic receptors
dopamine
for gratification
smooths movements
lack of it causes Parkingson's disease
L-Dopa drug helps with getting more dopamine in the brain
it's the precursor of the hormone, so when it enters the brain, it's processed into dopamine
serotonin
makes feel happy
found in blood and digestive tract
lack of it causes depression
serotonin reuptake inhibitors are used to treat it
limit serotonin breakdown, so it's more present in the synaptic cleft
Prokaryotic cells
characteristics
single celled
no nucleus
no membrane
so no membrane bound organelles
from the prokaryotic kingdom
can be bacteria and cyanobacteria
simpler than eukaryotic cells
smaller
Eukaryotic cells
characteristics
compose multicellular organisms
have nucleus
have membrane
plasma membrane
phospholipid bilayer
hydrophilic head
hydrophobic tail
lipid chain
the heads cover the extern and intern of the membrane
the tails remain on the inside of the membrane, away from water
channel proteins
help communicating from the inside and the outside of the cell
two types
animal cell
plant cell
organelles of the plant cell
vacuole
contains water
cell wall
keeps the cell protected and turgid
chloroplast
does photosynthesis
tonoplast
it's the vacuole membrane and helps with transpassing substances
pits
allowswater enter through cells
plasmodesmata
helps extracellular transport
similarities
have membrane bound genetic material
have a cell membrane to contain organelles
mithocondria helps with cell respiration
Action Potential
it's the movement of an impulse across the neuron
resting potential
when there's no action
it stands at -70mV
an event hapens and the mechanical gates open up
positive sodium ions enter
the membrane potential needs to be more than -55mV to activate the sodium channels activate and more ions enter
the potential goes up to 40mV
the potential triggers the channels nearby, so the signal goes through the axon to the synapses
at the action potential, the potassium channels open up, which takes to the cell two potassium ions and releases three sodium ions, so the membrane has a repolerisation
the membrane briefly hyperpolarizises and goes down to -75mV, but the potassium channels at the end balance the potential and goes back to -70mV
from the action potentialand the resting potential period of time, the axon can't act on another stimulus to prevent signals gong in opposite direction
refractory period
Calculating Magnification
it's how large the image compared to reality
magnification= image size / actual size
M=I/A
each value has to have the same unit