Biology

im Egyptian chemist and microbiologist and i want to ask who is the person that have license to open clinical laboratory and make the experiments in clinical lab in egypt the law give license to chemists or biochemists if they take post graduated diploma of biochemistry after bsc to open clinical lab for chemistry only aslo the law give license to microbiologists if they take post graduated diploma of microbiology after bsc to open clinical lab for microbiology only aslo the law give license to physicians if they take master degree of clinical pathology after bachelor of medicine( although the physician dont know any thing about biochemistry or chemistry o…

This is the action potential duration of a normal cardiac myocyte Here are the potential pace makers. * SA node: 80 - 100 bpm * Atrial foci: 60 - 80 bpm * Junctional foci: 40 - 60 bpm * Ventricular foci: 20 - 40 bpm 1. First of all let's say ventricular foci is the pacemaker. Why does it give a low heart beat? Is it because it decreases the duration of the action potential or frequency of the signal? 2. When heart rate is increased by nerves, the action potential duration decreases, I want to know how this occurs? How can nerves control the ions in the extracellular medium? or do they control the sodium channels? I'm just interested in how an acti…

What is the precise trigger for a cat to go into heat or come out of it? I understand the basics. What I am looking for specifically is the physiological reactions and brain chemistry changes. Does anyone know this or know where I can find it?

What makes it release back into the synpatic cleft? Also in other scenarios I have seen some ligand or something attaches to a receptor and then get released without any mention why it happened? If anyone can help. It would be great. Thanks

Hello guys, I know they are dead cells, but how come all the dead cells don't fall and only some do. If these cells are attached by cell adhesion molecules how do they fall? Are these adhesion molecules broken or something? Thank you

Hi I have to do a biology write up and it seems to be going OK so far. The title of the essay is "The Effect of Changing the Concentration of an Enzyme on the Rate of an Enzyme Catalysed Reaction". Obviously in this case, the increased concentration of enzyme results in an increased rate of reaction, up to a given point, when finally all of the active sites of the enzyme are used up. However the question that occurred to me (and one not asked in the essay) is what would happen if you just kept adding more substrate and simply replenished the substrate as it was used up? In other words, would the enzymes continue to work indefinitely? Would they never stop working? And if …

We've had the bird flu possibly mutating into a human concern, and now the swine flu. Why don't our pets -- which spend way more time near us (i.e. humans) -- get a flu that spreads with the potential for mutating into something that affects humans? Why only birds and swine? Is this going to be a regular occurrence now, with every few year a new animal might transfer a new flu strain to us? Maybe chicken flu, or hamster, garden snakes, etc.

Hello guys, Although the response of a motor unit is all-or-none, the strength of the response of the entire muscle is determined by the number of motor units activated. Nerve impulses passing down a single motor neuron will thus trigger contraction in all the muscle fibers at which the branches of that neuron terminate. and this is a motor unit. 1.My question is some organs are supplied only with one motor neuron, is it impossible for them to control the strength of their contraction? 2.Also this is just about the central nervous system. Since CVS has many nerves which are branches of other nerves, when an action potential is sent how come this action potential…

Hello guys, So there are hydrogen ions inside the cell which is pumped out in cellular respiration. Now my question is when they say hydrogen ions are inside the cell are these actually dissolved in water, ions can not exist without being dissolved right, why is that they are so reactive otherwise. Also in diffusion when they say hydrogen ions are taken in by the cell, does water come with it because they are dissolved. So does osmosis and ion diffusion occur together. Thanks

Hello. Just wanting some info re preparing samples for permanant slides. 'dry' things I have no problem with, since they are not at risk of mould attack or decay etc. my question is this: - if I want to do a permanant slide of something living eg bacteria or other cells, how do I prepare them? - do I need to do anything in particular to make them more visable eg stain, and in what situations would I use what stains? - do I have to allow food for the little guys, or can I just seal down the cover slip as is? - how do I preserve the little bacteria or whatever on the slide so I can continue to admire them in a years time? Ta thanks for any help with this …

Hello guys, So is tetany repeated involuntary contractions or just one smooth contraction? If the rate of action potential is rapid wouldn't that give repeated contractions? Also cardiac muscle doesn't have tetany for some reason? Thanks for anyone who can improve my understanding of tetany. Thanks!!

Hello guys, I always thought it did but it seems that it is actually a consequence of acidosis. According to this article http://www.unm.edu/~lkravitz/Article%20folder/lactate.html The article sounds right. So I was thinking the wrong thing all the time. Thanks

One way muscle grows is muscle hypertrophy where sarcoplasmic fluid increases inside the muscle cell. Wouldn't this burst the cell membrane, I can understand how organelles can replicate but what about the cell membrane. I know this sounds like a stupid question but please help. Thanks

I am currently a junior enrolled in High School and had a school project on cloning. I wrote up ten interview questions and contacted a local Medical college and got in touch with a cloning expert. I e-mailed him the questions but recieved no response. That was two weeks ago and now I am without answers to these questions and at the edge of the due date. Quick Responses please! If you could please take the time to answer some/all of my questions it would be immensely appreciated 1. In your own words could you please describe the cloning process. What does the cloning process involve? 2. How difficult is it to successfully clone someone? Does it become more difficul…

If your skin is cut deeply, meaning a cut to dermis why is that we can see scar tissue. I mean if the cut region in the dermis would be replace by scar tissue, but the epidermis region above that would have normal epithelial cell because they can divide easily. So if the epidermis grows back normally how can we see scar tissue? Thanks

Is the spongy bone covered by compact bone? I mean is it only when you cut the top bit(compact bone) you can see the spongy bone? I know the pics are self explanatory but just like to clarify. I hope you don't mind. Thanks Merged post follows: Consecutive posts mergedYes it is. Compact bone tissue forms the external layer of all bones . Sorry guys I take responsiblity for not doing research before hand. I actually did but only now did I find it.

Some of you might know I ask similar question under the thread of Animal testing, right or wrong... but I since I think probably it is well off that topic, so I start another thread Ok, here is the question, Indeed scientists do test cosmetics and medicines on animals, but how do they determine whether it will be accurate result??? Some ppl say Animal testing does save alot of life, on cotradictory, some said it does not obtain you a reliable result So, from an scientific point of view, is there any info on Internet could tell about the accuracy potential in animal testing controlled by scientists??? thx alot for ANY respond Albert

My question is just stated on title, in the course of hemoglobin isolation from blood sample, why protease inhibitors don't need to be added? Wouldn't proteases degrade the Hb after cell burst? (I was told that proteases are activated after cell burst, though I don't know the actual mechansim)

In the eye of a mammal, lets say a human or a primate, is it the rods and stuff in the eye or the brain itself that cannot process infrared and ultraviolet electromagnetic frequencies?

Can Chemosynthetic organisms create a sustainable oxygen atmosphere in subterranean Mars?

Have you ever had fish? Would you ever take your fish to the vet? Do you think fish have a three second memory? As part of a PhD research study at The University of Western Australia, we are now seeking volunteers to complete a simple, short online survey. This study aims to give us a better understanding of why people keep fish and what factors can influence the welfare of aquarium fish. It doesn't matter if you are an expert aquarist, just starting out, or have never even owned fish. All answers will be appreciated. The survey takes just 10-15 minutes, is totally anonymous, confidential and can be completed online. For more information and to take pa…

If say we can survive on Mars and there's oxygen and food and water, I wonder what kind of effects will there be on the human body. Since Mar's gravity is weaker than Earth.

It has been a routine practice to estimate a protein's amount by preparation of a standard calibration curve by BSA and with a spectrophotometer, followed by comparison with absorption of the sample protein. But I have been confused if this technique is to determine the concentration of protein (in molar) or the amount of protein (in milligram per litre). I have heard of both approaches. When I check how the component Coomassie blue in Bradford reagent work, it is found that this dye binds to protein molecules proportionally (not dependent on protien length), so I would then think using this technique to deduce protein concentration would be a suitable one, but I coul…

Hello guys, I checked coagulation but I can't find the explanation of how blood (serum) suddenly turn into solid? How does this occur? Thank you!!

Nerve and muscle tissue don't grow back much but epithelial cells in the skin grow very quickly. Why is that some tissues find it difficult to grow back and are replaced by fibrous scar tissue. Can't they do some mitosis and regrow? Thank you