Term
Name the cellular property which corresponds to the electrical component
Resister
Capacitor
Conductor
Battery |
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Definition
Closed channel
Cell membrane
Open membrane
Membrane voltage protential |
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Term
| What is the driving force? |
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Definition
DF = Vm - Ex
desire for the ion (x) to flow into or out of the cell |
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Term
Nernst equation?
What does it mean? |
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Definition
Ex = -RT/(ZxF) ln([X]i/[X]o)
means the potential of the ion is dependent on ratio of concentrations of ion (x) in log scale |
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Term
Which way does an inward current flow? What is it's charge?
Which way does an outward current flow? What is it's charge? |
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Definition
Inward = (+) into cell, negative
Outward = (+) out of cell, positive |
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Term
What is the resting cell's membrane potential?
What is Nernst for most cells for the following ions...
Na+
K+
Ca+2 |
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Definition
At rest = -90mV
+67 mV
-95 mV
+123 mV |
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Term
| What ion is the outward rectifier in the cell? What one is the inward rectifier? |
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Definition
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Term
| Describe the phases of an action potential and what ion channels open and close and inactivate during? |
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Definition
| V-gated Na+ open first and causes sharp upshoot of Vm. They inactivate immediately. Vm gets more (-) again when K+ open. They are slower to open and to close--causes hyperpolarization undershoot before Vm returns to normal. Ca+2 channels can cause plateau in AP. |
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Term
| Define absolute and relative refractory periods. |
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Definition
Absolute = can't trigger another AP no matter how much stimulus.
Relative = can have another AP at extra cost to cell |
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Term
| Describe structure of V-gated K channels |
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Definition
> made of 4 identical units with 6 domains in each unit that come together to make one channel.
> S4 domain is voltage sensor and has (+) lys and arg residues
> S6 makes up part of channel, size of pore matches ion. Ion will bind alpha carbonyls
> also accessory units to regulate folding/function |
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Term
Low Ca+2 outside makes Na+ channel opening ______ likely
and the tissues __________
It ___________ the voltage threshold |
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Definition
more likely
hyperexcitable
reduces |
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Term
| Along with voltage, increasing Ca+2 inside cells will _____ probability of K+ channel opening. |
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Definition
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Term
| Describe what osteoblasts and osteoclasts do in bone remodeling. |
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Definition
Osteoblasts build bone
Osteoclasts break it down. |
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Term
| What is intramembranous ossification and what bones do it |
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Definition
| Bone forms from mesenchymal cells which migrate out and spread out. No template needed. Done in flat bones. |
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Term
What is endochondral ossification and what bones do it.
What is primary and secondary? |
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Definition
Method of making bone where hyaline cartilage forms the template first which is replaced with bone. Long bones are made this way.
Primary = middle of cartilage out
Secondary = at epiphyseal plates in ends of long bones. |
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Term
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Definition
| has type III collagen, found in fetal bone and damaged healing bone. should never be found in adults or else there's a problem |
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Term
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Definition
| when osteoblasts seal themselves inside bone and become osteocytes. |
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Term
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Definition
also called Haversian system. consists of type I collagen concentric ringed canal formed around a blood vessel. rings run in opposite directions to make bone stronger.
compact bone. |
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Term
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Definition
no osteons, arranged in trabeulae
seen in short, flat, and irregular bones
lighter and has red bone marrow |
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Term
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Definition
| increased osteoclast activity in postmenopausal women as result of estrogen withdrawal |
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Term
| what 2 control loops regulate bone remodeling? |
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Definition
hormonal to maintain Ca+ levels
mechanical/gravitational on skeleton |
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Term
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Definition
vitamin D deficiency characterized by inadequeate mineralization of bone
get Rickets in kids and Osteomalacia in adults |
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Term
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Definition
| inability of osteoblasts to make collagen due to low vitamin C |
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Term
| what happens when there's too much PTH? |
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Definition
| too much osteoclastic activity, too much Ca+2 resorption, brittle bones, muscles hypotonic. |
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Term
| what happens when there is too much VitD? |
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Definition
| too much inhibition of PTH, too little Ca+2 in the blood |
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Term
| Name the purines and pyrimidines |
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Definition
Purine = adenine and guanine
double ring structure
Pyrimidine = cytosine and thymine
single ring structure |
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Term
| what is a nucleoside? nucleotide? |
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Definition
nucleoside = base+sugar
Nucleotide = base+sugar+phosphates |
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Term
| what base pairing is more stable? |
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Definition
| C-G because they have 3 H bonds |
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Term
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Definition
> constricted region to which mitotic spindle fibers bind during mitosis and meiosis
>at the ends of chromosomes, sequences which are repeated to limit DNA shortening during replication |
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Term
Heterochromatin
Euchromatin |
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Definition
>DNA tightly wrapped around histones, not mitotic
>DNA is loose, site of active DNA replication |
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Term
define mutation
somatic
germline |
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Definition
cellularly heritable alteration in DNA sequence.
> arise in tissues not involved in gamete production
> arise in cells whose genes are carried to gametes |
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Term
| What causes Xeroderma Pigmentosum |
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Definition
mutation in ability to remove DNA pyrimidine dimers.
causes freckles which are linked to skin CA |
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Term
| Name the 4 major mechanisms of DNA repair |
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Definition
Nucleotide excision
Base excision
Mismatch repair
Direct repair |
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Term
| Define homologous recombination, translocation, and transposon |
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Definition
homologous recombination=similar strands of dsDNA interact and exchange
translocation=exachange of large chromosomal fragments usually caused by chemical or radiation
can be reciprocal or not
transposons=discrete DNA segments which move from one location on genome to another. |
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Term
| Define Robertsonian Translocation |
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Definition
| translocations between 2 acrocentric chromosomes which can give single metacentric chromosome and oos of the 2 short arms. |
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