A bunch of random Bio Questions

[onedirection]

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So did a quick notes review just wanted to clarify some random stuff

I have

If solute concentration is greater outside a cell, osmotic pressure on outside is low, vacuole will not remove water from its inside? Did I mess that up. Should it be osmotic pressure on outside is high, vacule WILL remove water from its inside?

How do you determine if interphase finishes and Mitosis starts. I know it has something to do with the DNA:Cytoplasm ratio but what was it exactly?

MHC I --> Viruses/cancers/things inside the cell already; MHC II things outside the cell/pathogens right?

Are both MHC I and MHC II present at the same time on a cell?

Centromeres are the organizing center for each chromosome is all I have for them. Anything else?

Is the Amino end of a Polypeptide the 3' or 5' end. What about the Carboxylic end?

Double checking increase temp, increase PCO2, physical exertion, decrease pH, decrease BPG leads to a rightward shift of Oxygen dissociation cure?

Fetal Hb is a leftwards shift as a result?

I have this written:
"Distension: increased pressure from water on lungs" is that right?
Also stretch receptors of lungs stimulated by distention. An inhibition of stretch receptors lead to a decrease in depth and rate of breathing right?


I also have this written. Lungs have cillia. Is that right?
I also have cillia is needed for air to enter fallopian tube in my respiration section...is that true. I know cilla is involved with eggs to eject. I think i just miswrote egg there

What exactly is the purpose of an endosom? I have clathrin coated pits are means of forming endosomes and that's it

I have this wrttein. Unsure if it's correct
The more plasma therefore filtered out into Bowman's capsule and will icnrease solute concentration in glomerulus; this will decrease rate of filtration due to the loss of normal gradient.

That did not make sense to me. Wouldn't it be the opposite?


What is segmentation exactly in digestion? I have mixing of intestinal contents, breaking large particles to smaller ones. Allows for alternating contractions. But what does that mean?

What are the Haverisan canals exactly in bones? Is that just where everything is stored. It is analagous to the kidney's nephrons?

Tetanus vs Rigor Mordus
Tetanus is lack of Calcium and Rigor Mordus is lack of ATP right
Are both sustained contractions?


Ligae/Lyase aren't they basically the same thing? Except Lyase can also deal with removal of a bond?


Opsonization with immunology? I couldn't read my handwriting

 

[monkeyvokes]

So did a quick notes review just wanted to clarify some random stuff

I have

If solute concentration is greater outside a cell, osmotic pressure on outside is low, vacuole will not remove water from its inside? Did I mess that up. Should it be osmotic pressure on outside is high, vacule WILL remove water from its inside?
If there are no penetrating particles, tonicity is the same as osmolarity (both hyper or both hypo). If a solution is hypoosmotic, it is always hypotonic. If there are penetrating particles and a solution is isoosmotic or hyperosmotic, then it is hypotonic.

How do you determine if interphase finishes and Mitosis starts. I know it has something to do with the DNA:Cytoplasm ratio but what was it exactly? Hadn't read about a DNA/cytoplasm ratio, what about levels of cdk rising and MPF forming?

MHC I --> Viruses/cancers/things inside the cell already; MHC II things outside the cell/pathogens right? yes MHCI are present on all nucleated cells (so no RBCs). They are histocompatibility complexes (appropriately named), and if something is foreign like a virus or cancer then they will present foreign peptides to call attention.
MHII - yeah, and those are on antigen presenting cells, macrophages dendritic cells and B cells. These do foreign peptides because they can phagocytize them, prepare them in a phagolysosome, and present them on MHCII.

Are both MHC I and MHC II present at the same time on a cell? Only for cells that have MHCII and are presenting something I believe.

Centromeres are the organizing center for each chromosome is all I have for them. Anything else?
Centromeres are the "center" of a chromosome. They can be metacentric (in the middle), sub metacentric (just below middle), acrocentric (end), or telocentric (very end). They are the middle portion where, following S phase, you've got two strands of DNA connected by cohesin protein at the centromere.
The microtubule organizing center is called the centrosome, and is composed of centriole paires. The microtubule structure is similar to that of a basal body (flagella). They orient the cell. Microtubules are found in flagella and cilia, used during mitosis and meiosis, and are used for axonal transport (kinesin and dynein) of vesicles.

Is the Amino end of a Polypeptide the 3' or 5' end. What about the Carboxylic end?
peptides are translated from mRNA 5' to 3' end. 5' is amino, 3' is carboxy terminus. So, the very first amino acid (methionine, AUG) will stick out its amino terminis while the second amino acid is attached to its carboxy terminus.

Double checking increase temp, increase PCO2, physical exertion, decrease pH, decrease BPG leads to a rightward shift of Oxygen dissociation cure?
A right shift is indicative of decreased affinity for oxygen on hemoglobin. If CO2 rises, hemoglobin's affinity drops (makes sense). Physical exertion would also cause this, due to a rise in respiration. Increased CO2 decreases pH via carbonic anhydrase. 2,3-BPG increases the O2 affinity. This is commonly discussed in the context of high altitudes.

Fetal Hb is a leftwards shift as a result?
yes fetal Hb has a higher affinity for O2 than the mother's adult hemoglobin does. Adult is 2 alpha 2 beta, I believe fetal is 2 alpha 2 gamma.

I have this written:
"Distension: increased pressure from water on lungs" is that right?
Also stretch receptors of lungs stimulated by distention. An inhibition of stretch receptors lead to a decrease in depth and rate of breathing right?
Not sure about the distension/water thing. But, increasing pressure activates baroreceptors. Baroreceptors are reflexive and mediate blood pressure in the short term, like if you stand up to fast and experience orthostatic hypotension.


I also have this written. Lungs have cillia. Is that right?
I also have cillia is needed for air to enter fallopian tube in my respiration section...is that true. I know cilla is involved with eggs to eject. I think i just miswrote egg there
I do not believe that lungs have cilia. However, our throat does (ciliated pseudostratified columnar epithelium). I don't know why air would enter the fallopian tube or how this would be facilitated by cilia, but fallopian tubes do use cilia/fimbriae to guide eggs.

What exactly is the purpose of an endosom? I have clathrin coated pits are means of forming endosomes and that's it
If I remember correctly, those are little pits in the membrane on prokaryotes. They are little special environments that can be used for a variety of functions, analogous to cellular respiration.

I have this wrttein. Unsure if it's correct
The more plasma therefore filtered out into Bowman's capsule and will icnrease solute concentration in glomerulus; this will decrease rate of filtration due to the loss of normal gradient.

That did not make sense to me. Wouldn't it be the opposite?
Not sure if increasing GFR will necessarily increase solute concentrate in the glomerulus, seems likely though. There's a basement membrane with ions, pyramidal cells (i think that's what theyre called), and one other layer that filters the fluid entering the nephron. Some stuff gets left behind, so it seems likely that concentration would increase following removal of fluid.

What is segmentation exactly in digestion? I have mixing of intestinal contents, breaking large particles to smaller ones. Allows for alternating contractions. But what does that mean?
Think of the large intestine, it looks segmented. peristaltic contractions in large and small can mix chyme.

What are the Haverisan canals exactly in bones? Is that just where everything is stored. It is analagous to the kidney's nephrons?
I believe haversian canals are small hollow structures in bones where blood vessels traverse. They are surrounded by concentric circles (lammelae- sp?) and I believe connected by canaliculi canals. There is probably a good picture of this structure in one of your anatomy or bio books.. or google.
The nephron is the functional unit of the kidney. What is the function unit of the skeletal system? not sure, but the functional unit is what can perform the operations of that system, like a neuron for nervous. I believe the haversian canal is just a void where vessels travel, cos bone is vascular tissue.

Tetanus vs Rigor Mordus
Tetanus is lack of Calcium and Rigor Mordus is lack of ATP right
Are both sustained contractions?
Tetanus is usually temporary and results from continuous stimulation/summation.
Yeah rigor mortis is when you are no longer making ATP and myosin heads can no longer be released from actin (because this processes utilizes the hydolysis of ATP - sliding filament theory).

Ligae/Lyase aren't they basically the same thing? Except Lyase can also deal with removal of a bond?
A ligase is an enzyme that binds two molecules together. For instance, DNA ligase will connect two pieces of DNA during replication. Just as a ligand will bind to a receptor (greek root word is ligandum, i believe, and it means "to bind").
a lyase is an enzyme that separates two molecules. I believe this one is nonhydrolitic, as hydrolitic lyases are usually called hydrolases. Root word here is lyse, like if a cell lyses it breaks apart.

Opsonization with immunology? I couldn't read my handwriting
opsonization is when something is tagged by an opsonin. For instance, a function of antibodies is to act as opsonins, they can bind to foreign peptides and "tag" them so the rest of the immune system notices.

 

[onedirection]

Another random thing

What is the coelom exactly

and the primitive streak

Also

Dorsal Root, Ventral Root
White Matter/Gray matter, I understand the myelinated vs not myleinated part

I think white is myleinated but what else should we know

 

[monkeyvokes]

Another random thing

What is the coelom exactly

and the primitive streak

coelom is internal body cavity, one of the halmarks of chordates i believe.
the primitive streak is basically a line that first begins to form during early embryological stages. The line sets up bilateral symmetry in the developing organism.

 

[sps27]

Awesome! This is too good, and very helpful. You guys are ready! I think. Some of my thoughts and questions here.....

What is a vacuole? Plant cell, correct, vascular bundles, xylem, pholem that kind of thing. Ah now I remember, Temp storage of food in a plant cell. ?

How do you determine if interphase finishes and Mitosis starts? Related to judgement points at the end of G1 phase, where a cell decides if it is going to divide. Correct?

MHC I v/s MHC II --> I couldn't tell if MHC 1 was in plasma cell only and MHC II was in T helper cell only.

Centromeres, mictrotubles etc. ??? Did not know there were so many. Thanks monkeyvotes....

Fetal Hb is a leftwards shift as a result? Thanks! Once again, no clue on this one. Have to read it. What is 2 alpha, 2 beta, gamma etc ?

I don't know why air would enter the fallopian tube or how this would be facilitated by cilia, but fallopian tubes do use cilia/fimbriae to guide eggs????? Cilia is like a forward stroke for egg like rowing bars in rowing.....

What exactly is the purpose of an endosom? I have clathrin coated pits are means of forming endosomes and that's it..... Could be wrong but TBR has something on this, esp., how insulin acts via cathrin coated pits etc....chapter on endocrine... and endosome, is it related to pinocytocis....

What is the function unit of the skeletal system? Called an Osteon. It is basically Haversian canal and lamella and canaculi and blood vessels and cells like osteocytes, osteoblasts etc.

Opsonization with immunology? Never heard of Opsonization, so thanks on that.

 

[monkeyvokes]

Awesome! This is too good, and very helpful. You guys are ready! I think. Some of my thoughts and questions here.....

What is a vacuole? Plant cell, correct, vascular bundles, xylem, pholem that kind of thing. Ah now I remember, Temp storage of food in a plant cell.
I believe vacuoles take different forms. I got a question about vacuoles wrong once lol so hopefully it stuck with me now. They can be central vacuoles that usually get large over a plants lifetime and I think are mostly water. They can also be food vacuoles, which as you said store "food" for the plant. They can also be contractile I believe.

How do you determine if interphase finishes and Mitosis starts?
Related to judgement points at the end of G1 phase, where a cell decides if it is going to divide. Correct?
yeah are you talking about the checkpoints?
also a good sign that mitosis has begun is that prophase begins. Prophase involves condensing chromosomes, nucleolus fractures, and microtubule spindle forms. These three are due to the actions of MPF, so beginning mitosis correlates with MPF levels. Interestingly, the exact opposite happens in telophase when MPF drops off (chromosomes uncoil, nucleus reforms, and spindle fibers disassemble)


MHC I v/s MHC II --> I couldn't tell if MHC 1 was in plasma cell only and MHC II was in T helper cell only.
Wha? MHCI should be in all cells except RBCs. MHC-II is more for antigen presenting following phagocytosis. Antigen presenting is really interesting, it's like our cells will chop up the invader and hang pieces of it outside of itself. Sounds like something a pirate ship would do.

Centromeres, mictrotubles etc. ??? Did not know there were so many. Thanks monkeyvotes....yeah. telocentric doesn't occur in humans fyi

Fetal Hb is a leftwards shift as a result? Thanks! Once again, no clue on this one. Have to read it. What is 2 alpha, 2 beta, gamma etc ? those are the subunits. Think quaternary structure. Hemoglobin is a tetramer, so there are four sub units. Four chains of amino acids that connect to form hemoglobin.
Adult hemoglobin can also be written as alpha2beta2, because two of the sub units are of the alpha form and two are of the beta form. Fetal hemoglobin contains two gamma instead of two beta, the gamma must translate to better o2 affinity.

I don't know why air would enter the fallopian tube or how this would be facilitated by cilia, but fallopian tubes do use cilia/fimbriae to guide eggs????? Cilia is like a forward stroke for egg like rowing bars in rowing.....

What exactly is the purpose of an endosom? I have clathrin coated pits are means of forming endosomes and that's it.....Could be wrong but TBR has something on this, esp., how insulin acts via cathrin coated pits etc....chapter on endocrine... and endosome, is it related to pinocytocis....
I believe an endosome-like structure would form during initial stages of pino and phagocytosis.

I have discussed the endosome in a microbiology class as being a little compartment with a slightly unique environment. Prokaryotes don't have organelles like we do, so this is a form of compartmentalization for them (as I understand it).

What is the function unit of the skeletal system?
Called an Osteon. It is basically Haversian canal and lamella and canaculi and blood vessels and cells like osteocytes, osteoblasts etc.
Ah yes, that's right. nice

Opsonization with immunology? Never heard of Opsonization, so thanks on that.
Yeah, antibodies do have several otehr functions as well though

 

[sps27]

Thanks bud! How the heck do you remember all of this? I would go crazy. And yes I did mean checkpoints. What is MPF btw? And you are correct about MHC I and II as well. I do need some revision there, with the cell mediated immunity stuff. Thanks for the other clarifications as well. Somehow Biology is much better remembered via discussions and clarifications as opposed to just plain reading, at least for me.

 

[monkeyvokes]

Thanks bud! How the heck do you remember all of this? I would go crazy. And yes I did mean checkpoints. What is MPF btw? And you are correct about MHC I and II as well. I do need some revision there, with the cell mediated immunity stuff. Thanks for the other clarifications as well. Somehow Biology is much better remembered via discussions and clarifications as opposed to just plain reading, at least for me.

no problem, I love talking about this stuff. I probably remember because for the last few years I have worked at a walk-in tutoring center at my university. MPF is maturation promoting factor. MPF forms when levels of cyclin increase when prophase begins. I believe it's a complex of cyclin and cyclin-dependent kinase (or something like that).

yes discussing biology is great.