Advanced Higher Biology 2016/17

Yeah, I do AH chemistry as well. So will have to check both documents. Thanks for letting me know!

No problem! Like to be helpful

In the course notes it says " Describe the fluid mosaic model of membrane structure"

What would this require us to describe exactly if that makes sense? Do we just talk about the fluid mosaic model's structure like phospholipid bilayer or anything more as well?

Talk about structure of phospholipid - draw an example chemical structure?

Talk about how they are arranged as a bilayer, with reference to hydrophilic and hydrophobic forces.

Talk about what makes this fluid

Talk about the "mosaic" part - other components e.g. proteins, cholesterol

Hey, thanks very much!

I came across this in the course notes from the SQA: "Nerve transmission is a wave of depolarisation of the resting potential of a neuron."

Now, FROM THIS ONLY my teacher says I am expected to define both : 'resting potential' and depolirisation'. However the only possible definition I see is that of a Nerve transmission? Am I correct? Am I missing something. I don't need the actual definitions if they are not from there.

You are expected to know what depolraisation and what a resting potential is.

Basically the nerve cell is at resting potential when it is not firing, so the resting potential is the normal potential difference across the membrane when the nerve cell is at rest.

When the neruotransmitter/ligand binds to the ligand gated ion channels, and lets Na+ ions in, the cell begins to depolarise i.e become more positive inside the cell as positive ions are flooding in. Normally the cells electrical gradient would be negative inside and positive outside. Eventually when the potential difference across the membranes reaches a point called the threshhold, the VOLTAGE gated ligand channels begin to open and flood the nerve cell with Na+ ions at a faster rate, causing a wave of depolarisation along the nerve cell.

So basically to answer your Q - depolarisation is when the inside of the cell rises slowly to be more positive than the resting potential and the resting potential is the normal potential difference of the nerve cell at rest when it is not firing/ preparing to fire.

You are expected to know what depolraisation and what a resting potential is.

Basically the nerve cell is at resting potential when it is not firing, so the resting potential is the normal potential difference across the membrane when the nerve cell is at rest.

When the neruotransmitter/ligand binds to the ligand gated ion channels, and lets Na+ ions in, the cell begins to depolarise i.e become more positive inside the cell as positive ions are flooding in. Normally the cells electrical gradient would be negative inside and positive outside. Eventually when the potential difference across the membranes reaches a point called the threshhold, the VOLTAGE gated ligand channels begin to open and flood the nerve cell with Na+ ions at a faster rate, causing a wave of depolarisation along the nerve cell.

So basically to answer your Q - depolarisation is when the inside of the cell rises slowly to be more positive than the resting potential and the resting potential is the normal potential difference of the nerve cell at rest when it is not firing/ preparing to fire.

Hey,

thanks a bunch! So then what is the action potential? Is that just a wave of depolarisation?

Yes an action potential is a wave of depolarisation that can propagate down an axon of a neuron. This means when one part of a neuron depolarises it triggers the adjacent part to depolarise and so on until the synapse is reached.

With regards to the flashacrd, it could be something like "describe how nerves transmit information"

Thanks!

Why do you keep getting banned? What is it you do?

Why do you keep getting banned? What is it you do?

I was going to ask the same question lol

Hahaha I don't know!!! I was speaking to someone (nothing bad) and I got banned and I was like da f.

Hahaha I don't know!!! I was speaking to someone (nothing bad) and I got banned and I was like da f.

I was wondering if anyone here was well into their projects and if anyone was doing something similar to Catechol Oxidase in apples. Really struggling to get the information I am searching for. Any advice would be greatly appreciated.