Biology Unit 3 Questions Megathread

[Russ]

in cells?

They're often stored in vesicles (phospholipid membrane bubbles basically). This prevents them from reacting with anything else. A good example of this is lysosomes - basically vesicles within certain immune cells which are used to  to digest pathogens. If the contents of these just floated around everywhere (lipases, proteases, nucleases etc.),  the cell would practically eat itself.

Probably also worth mentioning that they can also be stored on the vesicle membranes and when needed, the vesicle fuses with the cell membrane to insert the protein (eg GLUT4 transporters + insulin)

[Kaille]

in cells?

They're often stored in vesicles (phospholipid membrane bubbles basically). This prevents them from reacting with anything else. A good example of this is lysosomes - basically vesicles within certain immune cells which are used to  to digest pathogens. If the contents of these just floated around everywhere (lipases, proteases, nucleases etc.),  the cell would practically eat itself.

Probably also worth mentioning that they can also be stored on the vesicle membranes and when needed, the vesicle fuses with the cell membrane to insert the protein (eg GLUT4 transporters + insulin)

so are they found as amino acids there? or do they needed to be converted to enzymes or hormones first before being stored? also do plants store protein? don't legumes like lentils have heaps of protein?

[shinny]

in cells?

They're often stored in vesicles (phospholipid membrane bubbles basically). This prevents them from reacting with anything else. A good example of this is lysosomes - basically vesicles within certain immune cells which are used to  to digest pathogens. If the contents of these just floated around everywhere (lipases, proteases, nucleases etc.),  the cell would practically eat itself.

Probably also worth mentioning that they can also be stored on the vesicle membranes and when needed, the vesicle fuses with the cell membrane to insert the protein (eg GLUT4 transporters + insulin)

so are they found as amino acids there? or do they needed to be converted to enzymes or hormones first before being stored? also do plants store protein? don't legumes like lentils have heaps of protein?

They would have already been translated to their functional form. There's no point storing amino acids because when the cell needs that particular enzyme or hormone, it won't be readily available. The point of storage is so that such proteins can be released en masse at demand. And yeh, I'd assume plants would. Obviously my knowledge of botany isn't as good as my knowledge of the human body, but I can't see any reason why they wouldn't. Well more so, I see a necessity why they would need to.

[lbeste12]

hey guys.

i was just wondering if there was a particular structure to answering a question in biology.
like, 3 marks = 3 points.
and do you answer it in a structure of like answer, explanation etc.

adding a structure to my answers i think would really help!!

[lbeste12]

also. what would a couple of errors be in an enzyme SAC.

liver cubes in a test tube, with added detergent and different concentrations of hydrogen peroxide.

[Russ]

hey guys.

i was just wondering if there was a particular structure to answering a question in biology.
like, 3 marks = 3 points.
and do you answer it in a structure of like answer, explanation etc.

adding a structure to my answers i think would really help!!

Three marks = three points, yes. My structure is basically to make a statement answering the question (1mark) and then provide either examples or further reasoning for 1 mark each until I reach the required amount. If it's a broader discussion questions (eg for 10marks) then I write structured paragraphs rather than 10 individual points. If you post a question I'll give you an example answer.

also. what would a couple of errors be in an enzyme SAC.

liver cubes in a test tube, with added detergent and different concentrations of hydrogen peroxide.

Experimental error (always) and insufficient time for reactions to occur are the two biggest ones I can think of

[pi]

also. what would a couple of errors be in an enzyme SAC.

liver cubes in a test tube, with added detergent and different concentrations of hydrogen peroxide.

This is copied directly from my SAC, we did a similar/same SAC:

One of the major factors that contribute to the rate of reaction is the concentration of the enzyme and substrate in the solution. The concentration of the substrate, hydrogen peroxide, was measured fairly equally. However, the amount of enzyme (catalase) wasn’t controlled accurately. Some pieces of liver were bigger than others, corresponding to varying amounts of enzyme quantity. If I have a chance to redo this experiment, I will be more careful in cutting up my pieces of liver to exact sizes.

[lbeste12]

thank you!

but...
how would you structure a question asking you to outline or describe an experiment you should design.

[Drunk]

What happens to the cell wall on a beetroot cell when the membrane gets damaged by an acidic solution? Pigment leaks out, so does that mean that the cell wall is penetrated as well?

[Kaille]

What happens to the cell wall on a beetroot cell when the membrane gets damaged by an acidic solution? Pigment leaks out, so does that mean that the cell wall is penetrated as well?

I'm pretty sure that the cell wall is quite porous. I know that the proteins will be denatured by the high acidity but i think that only affects its function, not its structure.

[dooodyo]

By penetrated if you mean that the pigment leaks out
of the cell wall, then yes. Remember that the cell wall
is permeable to everything, including solutions carrying
solutes as well.

[HERculina]

Why is it that wen you put a potato strip in a solution thats 5 % sodium chloride for 30 minutes the potato ends up losing more mass than one that was put in a solution that was 20% sodium choloride? (both hypertonic solutions)

[dooodyo]

Experimental error perhaps?

[HERculina]

nah it wasnt. my teacher sed its suppose to happen. I was thinking of something along the lines of greater concentration gradient = increased rate of diffusion? o.o

[HERculina]

are all coenzymes (the temporarily bound cofactors) organic?