Bmed 3100 unit 1

What is the function and make up of the cell membrane?

it is a selective barrier that acts as a physical protectant from outside contaminants. It is lipid based so allows hydrophobic materials to pass through. Polar outer layers with non polar fatty inner tails

What do we know about the nucleus?

manages DNA through transcription. Contains nucleotides (basic units of DNA), genes (sequences of nucleotides that code specific proteins), and chromatin (DNA and its associated proteins)

What do we know about the cytoskeleton?

In charge of cell shape and internal organization, intracellular transport, assembly of cells into tissues, and cell signaling

what do we know about the mitochondria?

Produce ATP, mitochondrial matrix is unique DNA that codes specific proteins for cellular respiration and ATP production, Parkinson’s disease is a mitochondrial disease

What do we know about metabolism?

can involve oxidation processes, kidney and brain use mainly Na and K ATPase while heart uses mainly Ca ATPase

What do ligands do and what are the 3 types?

Bond to receptors on cells, shape must match. Primary ligand and agonists activate the cell, antagonists block the cell receptors

What do we know about connective tissue?

3 types: proper (fat, tendon), dense (cartilage and bone), and loose. Function is for support, defense, transport, repair, and structure

What do we know about Muscular tissue?

3 types are skeletal, smooth, and heart. Functions are moving and maintaining posture(skeletal), voluntary and involuntary contractions (smooth and heart).

What do we know about nervous tissue?

Involves connection with the brain and the outside world. Types are central and peripheral. Functions are communication and regulation

What do we know about epithelial tissue?

Functions are protection, absorption, and secretion. Skin is an example

What are lumen?

spaces between tubes, tracts, and air cavities within the body. Air and substances move through the lumina.

What is the difference between electrical and chemical signals?

Electrical involves changes in the membrane potential of cell, where chemical signals are secreted by cells into the Extracellular fluid. Most signals in the body are chemical

What are the four types of close range signaling within the body and are th4ey each electrical or chemical?

Contact-dependent is chemical physical contact between the cells to transfer chemicals, Paracrine is also chemical but the cells need to be close together but not physically touching, Autocrine is electrical and the cell sends a signal to itself, and gap junction is also electrical where the cells come in contact and form a tunnel between them to pass signals.

What are the two long-range cell signaling processes?

Synaptic is chemical and involves axons delivering signals to far parts of the body (neurotransmitters), endocrine is electrical and travels through the blood entering cell membranes (Hormones)

What are the pieces in the cell signaling process in order?

1st messenger, membrane receptor protein, 2nd messengers, target proteins, response

What does a kinase vs a phosphatase do?

A kinase phosphorylates/activates, a phosphatase de phosphorylates/ deactivates

How do ion channel receptors work?

They bind water soluble messengers that open ion channels for ions to enter. Electrical process because it alters the membrane

How do enzyme coupled receptors work?

binds the first messenger, then a kinase phosphorylates proteins (ATP or energy is needed for this). Chemical process

How do G-protein receptors work?

they activate ion channels or enzymes through a complex of alpha, beta, and gamma cells.

What is the main function of integrin receptors?

to alter the shape of the cytoskeleton

How do we know from a graph if a cell is depolarizing or hyperpolarizing?

It depolarizes if the graph moves towards 0, and hyperpolarizes if the graph moves away from 0

What does it mean for a membrane to become more permeable?

More ions can pass through it easier

Should a cell always be in osmotic equilibrium (concentration) or chemical equilibrium?

osmotic equilibrium

What is the net charge of a protein?

negative

What does V_m represent?

permeability

What is thre goldman hodgkin katz equation?

permeability = 61 log (sum of permeability constants times concentration of positive ions out or negative in/ sum of permeability constants times concentration of positive ions in or negative ions out)

What are the three types of gated channels for graded potential?

Chemically gates channels respond to neurotransmitters/ligands (ex: insulin), voltage gated channels respond to voltage, mechanically gated channels respond to forces (involve cytoskeleton) (ex: stretch or pressure)

Where does graded potential vs action potential come from?

graded potential from the soma, action potential from the trigger zone at top of axon by soma

What is saltatory conduction?

when action potential jumps from one node to the next along myelinated axons. (voltage insulation keeps potential moving through the axons

Describe the parts of a neuron and where they are located with respect to each other

The soma is the cell body containing the nucleus and organelles, dendrites come off of the soma, the axon hillock is between the long axon tail and the soma and it where action potential is initiated, the axon terminal is where the axon meets the target cell, and the synapse is where the neurotransmission signal is sent

where are different chemically gated ion channels located along a neuron?

Cl- in the soma, K+ in soma and axon, Na+ in axon, Ca2+ in axon terminal

is synaptic transmission more ionotropic or metabotropic?

ionotropic

Describe the process of neurotransmitter release through synaptic transmission

neurotransmitters are synthesized and stored in vesicles, action potential arrives at presynaptic terminal and voltage gated Ca2+ ion channels open, Ca2+ allows vesicle docking and neurotransmitter release through exocytosis, neurotransmitters bind to receptors on postsynaptic cell and are then either metabolized or released, then postsynaptic potential is generated

what are the three types of postsynaptic cells?

neurons, muscles, glands

List the 4 methods of neurotransmitter deactivation

they are transported back into presynaptic terminal, uptake into glial cells (brain support cells), enzyme mediated degradation outside post synaptic terminal, or less likely but could be diffused out of the synaptic cleft.

How do ionotropic and metabotropic signaling work and which is faster.

Ionotropic / ligand- gated ion channels are faster and they involve ligands binding to ion channel receptors opening the channel, metabotropic/ g-protein coupled receptors work slower and involve neurotransmitters binding to g-protein coupled receptors which releases the alpha, gamma, beta cells and the alpha cells reach the gated channel to open it

which neurotransmitter is both excitatory and inhibitory but is excitatory on muscle cells?

Acetylcholine (Ach)

what deactivates Ach turning it into acetyl and choline

Acetylcholinesterase (AchE)

What is an acetylcholine receptor (AchR)?

cholinergic receptor that ionotropic or metabatropic

What is glutamate?

An excitatory neurotransmitter involving AMPA receptors (ionotropic) and NMDA receptors (ionotropic and metabotropic involving chemical and electrical signals), activation of both AMPA and NMDA leads to plasticity which when couples with Ca2+ allowing potentiation leads to long term potentiation or memory formation

What is GABA?

an inhibitory neurotransmitter that ionotropic chloride GABAa and metabotropic GABAb, and GABA transporters GAT that are symporters that transfer GABA, sodium, and chloride into neurons and glia

what are the different effects of presynaptic vs postsynaptic modulation?

presynaptic modulation affects the amount of the neurotransmitter released, postsynaptic modulation affects cell responsiveness through number of receptors, affinity, and identity of receptors