Official AQA Biology Unit 3 14th May 2013 NEW SPEC

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- how does the kidney filter?

The kidney filters the blood into the kidney tubule, meaning that the protein molecules (which are too large) stay in the blood. Selective reabsorption then occurs in the kidney tubule, all the glucose is reabsorbed into the blood by active transport. The water and mineral ions needed are then also reabsorbed. All the urea and excess mineral ions and water are then released as urine into the bladder

Reply 161

jonathanparkes

Original post by issie1234

- what is the process of ventilation?

Ventilation is breathing, it keeps the concentration gradient in the lungs high so that the most oxygen is diffused into the blood and the most carbon dioxide is diffused out of the blood.

Reply 162

Quantaˌ

Jonathan, try to edit your posts instead of double/triple-posting. Thanks!

Original post by issie1234

- what is the process of producing biogas?

Jonathan answered the others but anaerobic fermentation produces biogas in a generator.

By the way, the current question is still:

QUESTION: Compare a biogas generator and a mycoprotein fermenter. [2]

Reply 163

veniceswan

1. If the blood sugar is too high, pancreas will release a hormone called insulin which converts glucose in blood to glycogen in muscle cells and liver. If the blood sugar is too low, the hormone glucagon will be released from pancreas to convert glycogen in liver to glucose back into blood.

2. Kidney first filters blood. It reabsorb all glucose. It reabsorb water and ions. All urea is removed along with the excess ions and water as urine.

3. Inhaling - the rib cage will move out and up, making the diaphragm contract and becomes flat. It will be in lower pressure than outside so air is forced into lungs.
Exhaling - the rib cage will move down and in, making the diaphragm relax and becomes a dome shape. This forces air out as it is in higher pressure than outside.

4. Biogas is produced by anaerobic fermentation. Microorganisms converts carbon-rich materials into glucose and they respire to release energy, which is methane.

Sorry I am not really good at explaining, please tell me if I am wrong.

Original post by issie1234

You guys are all so good at answering the questions! I have most of the knowledge but under exam pressure I can hardly string a sentence together :/

Anyway, I'm confused about a few things and I was wondering if someone could explain them?

- can you give me a simple explanation of the whole glycogen/glucagon thing? What releases what from where?

- how does the kidney filter?

- what is the process of ventilation?

- what is the process of producing biogas?

Sorry for being annoying, I'm just a bit overwhelmed!

Thank you :smile:

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Reply 164

jonathanparkes

Original post by Quantaˌ

Jonathan, try to edit your posts instead of double/triple-posting. Thanks!

Jonathan answered the others but anaerobic fermentation produces biogas in a generator.

By the way, the current question is still:

QUESTION: Compare a biogas generator and a mycoprotein fermenter. [2]

Sorry,
Biogas generator is under anaerobic conditions while the mycoprotein fermenter allows the fusarium to respire. The mycoprotein fermenter is monitored and controlled while the generator is left and cleaned out if it is in batch.

What have I missed?

Reply 165

nicola12345

I'm new here so I'm not sure if this has already been mentioned...but in how much detail do we need to know about stents? My school booklet has everything from what they are , what they do, the benefits and the risks and how they are inserted etc in quite a lot of detail... but my revision guide only has a small section on them just briefly about what they do???

Reply 166

Captain Anonymous

if you do not mind could you please post the benefits and risks of them - as the books have limited detail. I think the more you know, the better it is :wink:

Reply 167

lolface32

Good luck on Tuesday people! :smile:

Anyone wanna play the revision game later?( doing French revision now)

Reply 168

Quantaˌ

Original post by lolface32

Anyone wanna play the revision game later?( doing French revision now)

What's the revision game? I might be play it- I've got some time.

Original post by jonathanparkes

No problem. Just reminding you.

You've not missed anything except writing another question. :wink:

The question was only two marks- you only needed to talk about the difference of respiration and fermentation.

Reply 169

lolface32

Original post by Quantaˌ

What's the revision game? I might be play it- I've got some time.

No problem. Just reminding you.

You've not missed anything except writing another question. :wink:

The question was only two marks- you only needed to talk about the difference of respiration and fermentation.

Not really a game, just asking questions back and forth :colondollar:

Wanna play later? If your on :redface:

Reply 170

georgemarsh203

I think the six marker may be on artificial hearts, stents and artificial heart valves? lots of advantages and disadvantages.

Reply 171

Quantaˌ

Original post by lolface32

Not really a game, just asking questions back and forth :colondollar:

Wanna play later? If your on :redface:

Sure. I've been trying to do it now- look at the last few threads. But there's not enough people interested and they don't always ask new questions once they've answered one.

Reply 172

techno836

can somebody give me a detailed answer to this question so I understand it ..

describe/explain negative feedback ? :smile:

Reply 173

MsFahima

Can I join this question game thing?

Reply 174

jonathanparkes

Original post by Quantaˌ

Sure. I've been trying to do it now- look at the last few threads. But there's not enough people interested and they don't always ask new questions once they've answered one.

Explain the effect of acid rain on trees [2]

Reply 175

Quantaˌ

Original post by MsFahima

Can I join this question game thing?

Sure! One person posts a question, anyone can answer but they need to make a question for the next person. You do need to say how many marks the question is worth.

Original post by jonathanparkes

Explain the effect of acid rain on trees [2]

I not sure about this one but I'll give it a shot: acid rain is slightly acidic and is absorbed by the trees via diffusion in the root hair cells. The acidic rain is transported to the leaves via the xylem and goes to the leaves. The acid denatures the enzymes in the leaves and stops photosynthesis from occurring. Therefore, the leaves fall and eventually the tree dies.

Explain how blood glucose is controlled [6]

(edited 10 years ago)

Reply 176

megan1997

All of the new things will definitely come up I think such as fishing, the small intestine and biogas. I am so worried for Tuesday, biology is my best science but I don't understand active transport or the lungs at all. Also does anyone know any ways of remembering which way certain blood is carried?

Reply 177

lolface32

Original post by Quantaˌ

Sure! One person posts a question, anyone can answer but they need to make a question for the next person. You do need to say how many marks the question is worth.

I'll start: Explain how blood glucose is controlled [6]

Let's roll :cool:

Blood glucose is controlled through the use of hormones secreted by the Pancreas. Where there is to much glucose, insulin is released by the pancreas and, through blood flow, is bought to our liver. The liver will convert glucose to glycogen. Likewise, where there is little glucose the pancreas secretes glucagon which then goes to the liver and converts Glycogen to Glucose :biggrin: