BIOL 1030H Lecture Notes - Lecture 4: Anaerobic Glycolysis, Myoglobin, Titin
26 Jun 2018
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Electrical charge of the membrane is approximately -70mV
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When the surrounding neurons send messages, they send positive charges and then once it
hits the threshold, it fires and gets to about 40mV, and then the potassium channels remain
open and sodium channels close.
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The potassium continues to leak out until it actual dips below resting potential
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Potassium channels then close and sodium channels open again
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Neurons communicate at specialied junctions called synapses
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You do not always need a chemical signal (ex. Gap junctions)
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Electrical signal (action potential) is converted to a signal then back to an electrical signal
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When you open the channel, calcium comes in and activates the vessicles that have the
neurotransmitters, which then make their way down to the membrane
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Synaptic transmissions begins with action potential conduction to the axon terminal
1.
Depolarization of the axon terminal opens voltage gated Ca2+ channels
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Vesicles respond by fusing with the presynaptic membrane releasing neurotransmitters into
the synaptic cleft
3.
Neurotransmitters bind with receptors on the post synaptic cell that are ligand-gated
channels, causing a charge in membrane potential
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After inactivation, neurotransmitters are reabsorbed into the presynaptic terminal and stored
in vesicles until the next action potential arrives
5.
Where does the initial stimulus come from?
Mechanoreceptors respond to pressure, by the protein deforming it sends an action potential
Animal Movement- Chapter 37
Biological motors that generate force
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Composed of multinucleated muscle fibers
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Use ATP generated through cellular respiration
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Contain contractile proteins (actin and myosin)
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Production of Movement
Categorization
Skeletal and cardiac muscle
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Actin and myosin arranged regularly, repeating pattern
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Striated- appear striped
Walls of arteries, digestive and excretory system
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Actin and myosin appear in an irregular pattern
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Smooth - appear uniform
Muscle belly has blood vessels running through it
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Muscle bundle is covered into connective tissue
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Inside of the muscle bundle, is the muscle fibre (cell)
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Nuclei are all over muscle fibre/cell
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Mitochondria are throughout the muscle cell
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Myofibrils make up the cell
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Organization of Skeletal Muscle
Thin (actin filament)- thin helix of actin
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Tropomyosin surrounds the thin filament, has another protein on it called troponin. Because
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Myofibrils contain thick and thin filament
Lecture 4
January 31, 2018
5:07 PM
Biology 1030 Page 1
Document Summary
Electrical charge of the membrane is approximately -70mv. When the surrounding neurons send messages, they send positive charges and then once it hits the threshold, it fires and gets to about 40mv, and then the potassium channels remain open and sodium channels close. The potassium continues to leak out until it actual dips below resting potential. Potassium channels then close and sodium channels open again. Electrical signal (action potential) is converted to a signal then back to an electrical signal. You do not always need a chemical signal (ex. Synaptic transmissions begins with action potential conduction to the axon terminal. When you open the channel, calcium comes in and activates the vessicles that have the neurotransmitters, which then make their way down to the membrane. Depolarization of the axon terminal opens voltage gated ca2+ channels. Vesicles respond by fusing with the presynaptic membrane releasing neurotransmitters into the synaptic cleft.
