Membrane Definition and 167 Threads

im meant to design an experiment (at AS level) and perform it to see how the pH can affect beetroot cell membrane permeability. i don't know where to start. anyone have any experiments?? thanks :biggrin:

I am currently looking into membrane biophysics as an area of research, and I will start doing some undergraduate research with one of my professors in his biophysic's labs. But I am curious how is the theory end of Biophysics looking, particularly for graduate programs. I have bumped into a...

Why exactly does the cell membrane become more fluid in higher temperatures than lower? Does it have anything to do with the degree of saturation?

You are accostumating me bad. I never find good sites for what I am looking for and you always find. This time I am looking for the various theories about the structure of the cell membrane till the fluid mosaic. Thank you one more time. :biggrin:

Hello there; In class we learn that "cholesterol increases membrane fluidity at low temperatures, and decreases membrane fluidity at high temperatures." I can see how it would increase fluidity at low temperatures since it attachs to the lipid tails of the membrane, which would push them...

hi, this is the last question I'm having trouble with.. the question is: Fine sand is sprinkled on the horizontal membrane, which vibrates in the vertical direction with frequency f = 500 Hz. The sand particulates bounce at the height of 3 mm over the level of the position of equilibrium of...

This is about membrane potentials in a nerve membrane. I've already studied the Nernst equation and the Goldmann equation, but I have found its significance in explaining the resting potential. The Nernstian potential occurs at equlibrium, when concentration gradient = opposing electric...

I have this question I need to answer and I am confused. I've checked my notes and book and can't find an answer. Here is the question: "Even though the beta barrel configuration for a transmembrane protein channel would seem an ideal channel, most of the channel proteins have multipass alpha...

cell membrane---please help me...--- :confused: What kind of molecules make up the majority of the cell's membrane? :confused: Can anyone help me?

The membrane of a cell is electrically equivalent to a parallel plate capacitor. A typical cell has a spherical shape with a radius 10 μm and it has a potential of −60 mV with respect to outside. The thickness of the membrane is about 0.01 μm, and it has a dielectric constant of 2. Find: (a)...

hi, my textbook shows how cholesterol sort of patches the cell membrane together, keeps it at optimal fluidity... I was just wondering how cholesterol is able to do this... I am in grade 11 biology I am not being tested on this or whatever I was just wondering if anyone knew...

there are 2 probs here. 1) The inner and outer surfaces of a cell membrane carry a negative and positive charge, respectively. Because of these charges, a potential difference of about 0.0680 V exists across the membrane. The thickness of the membrane is 7.95×10-9 m. What is the magnitude of...

Suppose you have a tube made of nylon. It is filled with air. Obviously, the cross-section is a circle. Now, suppose that on the top and bottom of the tube, a length of rigid sheet metal is attached and does not permit curvature, so that the cross-section after inflation looks like this...

http://www.google.ca/search?q=cache:0j8NdYaQ3L4J:www.foodsafetynetwork.ca/biotechres/activityextraction.pdf+Kiwi+DNA+Extraction+Lab&hl=en The above url is a lab that states that to do a DNA extraction of kiwi the cell membrane is eliminated through liquid detergent and mechincal mashing -...

i learned in my cellular biology class today that hydrophillic molecules don't diffuse through the membrane easily, since the inside of the membrane is hydrophobic. my question is that water easily diffuses through the cell membrane, and water isn't just hydrophillic, it is hydro! so why can...

Greetings. According to my textbook (again, this might not be really accurate because of translation): Now, here is my question : If proteins are just molecules (big ones i guess), how do they 'know' what the cell needs at a certain time (to let it into the cell) ? Thanks in advance.

I have noticed while looking at my cat that there is a secondary membrane (first beign the mucus membrane covering his eye it is a little har do expsplain so if you have a cat pick it up and look at it's eye you will notice a white area beteen his outside eye and the side of it's nose. It it...