Biology Unit 3 Questions Megathread

[Russ]

I have written a few so far, things got busy.
I will try to get some more done over the weekend.

Protein A is responsible for catalysing the transformation of reactant B into product C. If A is bound by another protein (D), which of the following is not a possible outcome:

A. The rate of reaction decreases
B. The amount of product at completion decreases
C. The rate of reaction increases
D. Protein A is degraded

Lipids are comprised of:
A. Hydrophobic heads and hydrophobic tails
B. Hydrophobic heads and hydrophilic tails
C. Hydrophilic heads and hydrophobic tails
D. Hydrophilic heads and hydrophilic tails

Production of ATP during aerobic respiration:
A. Is the same as the amount of ATP produced  anaerobic respiration
B. Always produces the same amount of ATP
C. Is slower than anaerobic respiration
D. Is less efficient than anaerobic respiration

Which of the following cell organelles contain hydrolytic enzymes:
A. Golgi apparatus
B. Lysosome
C. Mitochondrion
D. Endoplasmic reticulum

Where is the electron transport chain located:
A. mitochondrial outer membrane
B. mitochondrial matrix
C. mitochondrial inter membrane space (IMS)
D. mitochondrial inner membrane

[WhoTookMyUsername]

Thanks Russ

SPOILER ALERT:



Not sure by your first question if you mean they are inhibited but
C is the odd one out

2.C
3. C i think

4: B

5: B

[dooodyo]

Haha lol I concur, I had the same solutions.

However q1 is a bit iffy 
But C is probs the safest bet

[HERculina]

SPOILER ALERT TOO  
hm i got slightly different answers:
1.d (can protein D be a co enzyme? i dont know wat degraded means. it sounds like it means falling apart and enzyme A can become disfunctional but i dont think it can actuall fall apart physically...  :laugh:)
2. a (dont fats and oils have hydrophobic heads and tails - thought this was best answer cause phospholipids are conjugated lipids)
3. c (anaerobic respiration happens faster cause it doesnt need to undergo krebs cycle and ETC)
4. b (lysosomes contain enxymes that break down stuff... i rmb 'hydrolytic' = describing breaking bonds between molecules using water)
5.d (doesnt ETC happen in mitochondiral cristae which = inner membrane of mitochondria)

these q.s are a bit tricky. thanks Russ for making these q.s up for us
EDIT: waitttt changed my answer to 1. protein D cant be a coenzyme cause its a protein! so i choose c now)

[dooodyo]

Hey PhilDunphy,

Haha q 5 would be D, haha silly me

And for 2 I think its C since fats and oils are lipids, and a usually have a triglyceride structure and hence the hydrophobic fatty acid tails and hydrophilic glyerol head.

[Russ]

This thread has taught me I really need to proof read my questions. Never appreciated how hard it was for the VCAA lol

I did mean phospholipids (I think of them synonymously), so 2C
Everyone got 3C and 4B
5 could have been more specific and stated it was the proteins of the ETC I was asking about, but inner membrane was correct so 5D

And now for 1. Looking back, this is a slightly confusing question

I was intending for the answer to be B, on the principle that an enzyme won't change the final equilibrium (hence the at completion). Options A and C are both possible if protein D is an allosteric regulator, whilst option D is possible if protein D has some sort of proteolytic activity.
I was hoping people would be convinced that C couldn't be possible because we usually think of enzymes already being at the optimal efficiency.

Thoughts?

[WhoTookMyUsername]

I thought 1 implied it was an allosteric regulator but relooking at it that's not necessarily the case. I guess C is unlikely as all enzymes would have to be altered which usually does not occur so B is the best option.

5 ) i really need to cover the course before school starts, we are so far behind!

Thanks again russ

[WhoTookMyUsername]

Hydrolysis is the addition of a water molecule resulting in the release of energy (exergonic).
Why then is respiration, in which Water is a product, not a condensation reaction?

[Russ]

At a guess, because condensation is a specific subset of chemical reaction where you combine two small molecules into one large molecule and produce water as a byproduct, which isn't the case in respiration.

[HERculina]

also cellular respiration is catabolic and condensation reactions are anabolic. you cant have a reaction that is both

hm i reviewed biomolecules again (specifically lipids). i dont get this:
do fats and oils have a hydrophilic head? then why isnt it amphipathic?

and wat does conjugated specifically mean? i made a mistake before, phospholipids arent conjugated xD

[WhoTookMyUsername]

also cellular respiration is catabolic and condensation reactions are anabolic. you cant have a reaction that is both

hm i reviewed biomolecules again (specifically lipids). i dont get this:
do fats and oils have a hydrophilic head? then why isnt it amphipathic?

and wat does conjugated specifically mean? i made a mistake before, phospholipids arent conjugated xD

Thanks Russ, again !


 it seemed like they release water molecules and yet were hydrolytic which is also impossible

fats and oils do not have a hydrophilic head. Glycerol loses polarity when in a triglyceride an has only a small amount of polarity (insignificant to 3/4) when in a mono/di glyceride

Conjugated refers to 2 or more groups of biomacromolecules joined together , which a phosphate group IS NOT

[HERculina]

ahh i see

Russ can you plz please give us more q.s if you have time to

[WhoTookMyUsername]

I looked in my text and i don't actually know where Kreb's cycle occurs.

Glycolysis is in the cytosol
and the
ETC is ? on or in? the cristae

but i don't know where  Kreb's occurs :S

Somebody help

[Russ]

The matrix of the mitochondrion, the products are passed straight to the ETC in the inner membrane

Russ can you plz please give us more q.s if you have time to

I'll pick some from my tutoring collection and post a holiday sample work thread tonight.

[pi]

I looked in my text and i don't actually know where Kreb's cycle occurs.

I think Biozone has some nice spreads on these details