VCE Biology Question Thread

[Biology24123]

Do we need to know how to draw glucose

[cosine]

Do we need to know how to draw glucose

Yes, you should know the general structure of glucose and the elements involved, however, there is no need to know how to draw the types of different glucose isomers (alpha glucose, beta glucose).

[vox nihili]

If you're really stuck with natural selection/super interested in it, buy Darwin's book. You can get it as a popular penguin. Fascinating read and he does explain it really well

[StupidProdigy]

Why did neaderthals have larger cranial capacity than homo sapiens but weren't more advanced? I looked online and it said that it may have been because more of the brain was devoted to vision and body control, is that right? A yes or no answer is fine! Thanks!

[cosine]

It has come to my attention that phospholipids are composed of a glycerol backbone with 1 phosphate group attached and 2 fatty acid chains attached. So when we are writing the constituent sub units of phospholipids, must we include the glycerol backbone? Cheers.

[vox nihili]

Why did neaderthals have larger cranial capacity than homo sapiens but weren't more advanced? I looked online and it said that it may have been because more of the brain was devoted to vision and body control, is that right? A yes or no answer is fine! Thanks!

Sounds about right. Larger cranial capacity doesn't necessarily mean smarter. It's actually a pretty poor correlation (think elephant vs human for instance)

It has come to my attention that phospholipids are composed of a glycerol backbone with 1 phosphate group attached and 2 fatty acid chains attached. So when we are writing the constituent sub units of phospholipids, must we include the glycerol backbone? Cheers.

Yes

[warya]

Does glycolysis occur in both aerobic and anaerobic respiration?

[cosine]

Does glycolysis occur in both aerobic and anaerobic respiration?

That is correct, glycolysis can occur in both aerobic and anaerobic conditions. At first, glycolysis occurs without the presence of oxygen, in the cytosol of cells. If oxygen is present, the pyruvate will be transported to the mitochondria and aerobic respiration reactions will occur. If oxygen is not present in the organism, the pyruvate will undergo the anaerobic reactions.

[warya]

Thanks!

What are the inputs to Krebs Cycle? Is it just pyruvate and CO2?

[BakedDwarf]

Thanks!

What are the inputs to Krebs Cycle? Is it just pyruvate and CO2?

I thought CO2 is an output of the Krebs cycle since pyruvate is broken down to 3 CO2 molecules, 1 ATP molecule and 5 loader acceptor molecules.

[cosine]

Thanks!

What are the inputs to Krebs Cycle? Is it just pyruvate and CO2?

The inputs and outputs of the Krebs cycle include:

Inputs:
- Pyruvate
- Coenzyme A (CoA)
- NAD+
- ADP + Pi
- FAD+

Outputs:
-CO2
- ATP
- NADH
- FADH2

Quick rundown:

Pyruvate enters the mitochondrial matrix and reacts with Coenzyme A to produce one molecule of CO2, Acetyl CoA and one molecule of NADH. This Acetyl CoA goes on to react and produce another two molecule of CO2 and one molecule of ATP is released. Another 3 NADH and 1 FADH2 are also produced. Note this is only one molecule of pyruvate, but we know one molecule of glucose produces two molecules of pyruvate.

Hope this helped

[vox nihili]

Does glycolysis occur in both aerobic and anaerobic respiration?

No, it doesn't. Glycolysis is a form of anaerobic respiration. It is such because it does not require oxygen.

Aerobic respiration relies on the products of glycolysis, however, glycolysis is not considered a part of it.

I get what you're trying to ask, but the definitions are a little bit tricky. Aerobic means that it uses oxygen and anaerobic means that it doesn't. At the end of glycolysis, which is a process that produces energy (therefore respiration) but doesn't need oxygen (anaerobic) pyruvate can converted into lactic acid or go on to aerobic respiration (a process that needs oxygen [therefore aerobic] to produce energy [therefore respiration])

[cosine]

No, it doesn't. Glycolysis is a form of anaerobic respiration. It is such because it does not require oxygen.

Aerobic respiration relies on the products of glycolysis, however, glycolysis is not considered a part of it.

I get what you're trying to ask, but the definitions are a little bit tricky. Aerobic means that it uses oxygen and anaerobic means that it doesn't. At the end of glycolysis, which is a process that produces energy (therefore respiration) but doesn't need oxygen (anaerobic) pyruvate can converted into lactic acid or go on to aerobic respiration (a process that needs oxygen [therefore aerobic] to produce energy [therefore respiration])

My bad for saying that it does, forgive me warya!

So does that mean because it does not require oxygen, it is anaerobic, then the other two stages in cellular respiration require oxygen? When exactly is oxygen utilised in the Krebs cycle? Cheers

[mahler004]

My bad for saying that it does, forgive me warya!

So does that mean because it does not require oxygen, it is anaerobic, then the other two stages in cellular respiration require oxygen? When exactly is oxygen utilised in the Krebs cycle? Cheers

Oxygen isn't (directly) used in the citric acid cycle.

Oxygen is used in the electron transport chain/oxidative phosphorylation. This oxidises electron carriers, which may then be reduced again in the Krebs cycle.

[cosine]

Oxygen isn't (directly) used in the citric acid cycle.

Oxygen is used in the electron transport chain/oxidative phosphorylation. This oxidises electron carriers, which may then be reduced again in the Krebs cycle.

Oh so according to Mr T rav then krebs cycle is also anaerobic as oxygen is not used? Im confused.. :/