Login

Welcome, Guest. Please login or register.

March 29, 2024, 06:02:45 pm

Author Topic: VCE Biology Question Thread  (Read 3571394 times)  Share 

0 Members and 14 Guests are viewing this topic.

MM1

  • Victorian
  • Forum Obsessive
  • ***
  • Posts: 213
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #210 on: January 13, 2014, 08:07:30 pm »
0
What is the purpose of excitatory & inhibitory neurotransmitters? Thanks in advance.

alondouek

  • Subject Review God
  • Honorary Moderator
  • ATAR Notes Superstar
  • *******
  • Posts: 2903
  • Oh to be a Gooner!
  • Respect: +316
  • School: Leibler Yavneh College
  • School Grad Year: 2012
Re: VCE Biology Question Thread
« Reply #211 on: January 13, 2014, 08:19:44 pm »
+1
What is the purpose of excitatory & inhibitory neurotransmitters? Thanks in advance.

Well, consider the words 'excite' and 'inhibit'. They're opposites, right? It follows that excitatory and inhibitory neurotransmitters have opposite functions - that is to say, they both activate receptors (as is the function of any neurotransmitter) but the effect that follows can be unique. Excitatory neurotransmitters elicit an increased chance of the firing of an action potential by a receiving neuron (I'm assuming you know what this is, let me know if you need me to elaborate), while an inhibitory neurotransmitter does the opposite: it reduces the chance of a neuron firing an AP.
2013-2016
Majoring in Genetics and Developmental Biology

2012 ATAR: 96.55
English [48] Biology [40]

Need a driving instructor? Mobility Driving School

MM1

  • Victorian
  • Forum Obsessive
  • ***
  • Posts: 213
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #212 on: January 13, 2014, 08:30:54 pm »
0
Well, consider the words 'excite' and 'inhibit'. They're opposites, right? It follows that excitatory and inhibitory neurotransmitters have opposite functions - that is to say, they both activate receptors (as is the function of any neurotransmitter) but the effect that follows can be unique. Excitatory neurotransmitters elicit an increased chance of the firing of an action potential by a receiving neuron (I'm assuming you know what this is, let me know if you need me to elaborate), while an inhibitory neurotransmitter does the opposite: it reduces the chance of a neuron firing an AP.

Why would an inhibitory neurotransmitter reduce the chance of a neuron firing an AP?

grannysmith

  • Victorian
  • Part of the furniture
  • *****
  • Posts: 1303
  • Crisp and juicy.
  • Respect: +66
Re: VCE Biology Question Thread
« Reply #213 on: January 13, 2014, 08:40:15 pm »
+2
Why would an inhibitory neurotransmitter reduce the chance of a neuron firing an AP?

I believe inhibitory neurotransmitters bind to receptors in the post synaptic cell which make either chloride ions flood into the cell, or potassium ions move out of the cell. That is, chloride/potassium protein channels are opened.
Either way, the neuron becomes hyperpolarised and its membrane potential is made even more negative than the resting threshold.
In effect, the chance of generating an action potential (impulse) is decreased.

MM1

  • Victorian
  • Forum Obsessive
  • ***
  • Posts: 213
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #214 on: January 13, 2014, 08:45:47 pm »
0
I believe inhibitory neurotransmitters bind to receptors in the post synaptic cell which make either chloride ions flood into the cell, or potassium ions move out of the cell. That is, chloride/potassium protein channels are opened.
Either way, the neuron becomes hyperpolarised and its membrane potential is made even more negative than the resting threshold.
In effect, the chance of generating an action potential (impulse) is decreased.

I totally get what you mean, but I'm wondering what's the biological purpose/significance of having inhibitory neurotransmitters? Or maybe I shouldn't delve that far into it. Thanks though!

vox nihili

  • National Moderator
  • Great Wonder of ATAR Notes
  • *****
  • Posts: 5343
  • Respect: +1447
Re: VCE Biology Question Thread
« Reply #215 on: January 13, 2014, 08:48:05 pm »
+1
I totally get what you mean, but I'm wondering what's the biological purpose/significance of having inhibitory neurotransmitters? Or maybe I shouldn't delve that far into it. Thanks though!

They're circuit breakers of sorts. Otherwise the action potential would start in one corner of the brain and spread to all corners of the brain, creating a flurry of activity. Inhibitory neurones make it more controlled, they give the brain its finesse I guess.
2013-15: BBiomed (Biochemistry and Molecular Biology), UniMelb
2016-20: MD, UniMelb
2019-20: MPH, UniMelb
2021-: GDipBiostat, USyd

alondouek

  • Subject Review God
  • Honorary Moderator
  • ATAR Notes Superstar
  • *******
  • Posts: 2903
  • Oh to be a Gooner!
  • Respect: +316
  • School: Leibler Yavneh College
  • School Grad Year: 2012
Re: VCE Biology Question Thread
« Reply #216 on: January 13, 2014, 08:48:53 pm »
+1
I totally get what you mean, but I'm wondering what's the biological purpose/significance of having inhibitory neurotransmitters? Or maybe I shouldn't delve that far into it. Thanks though!

We can't have every neuron firing at once! That would overwhelm our system pretty badly - in fact, that what happens when epileptics have a seizure; their neurons are firing uncontrollably and they therefore can't consciously control their actions.

As such, inhibitory neurotransmitters "dampen" neurons so they can't fire all the time.
2013-2016
Majoring in Genetics and Developmental Biology

2012 ATAR: 96.55
English [48] Biology [40]

Need a driving instructor? Mobility Driving School

MM1

  • Victorian
  • Forum Obsessive
  • ***
  • Posts: 213
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #217 on: January 13, 2014, 08:57:42 pm »
0
We can't have every neuron firing at once! That would overwhelm our system pretty badly - in fact, that what happens when epileptics have a seizure; their neurons are firing uncontrollably and they therefore can't consciously control their actions.

As such, inhibitory neurotransmitters "dampen" neurons so they can't fire all the time.

Oh :P Now I get it haha! Cheers! So, would it be true to say that messages sent my these inhibitory neurotransmitters are of less importance; not that urgent?

vox nihili

  • National Moderator
  • Great Wonder of ATAR Notes
  • *****
  • Posts: 5343
  • Respect: +1447
Re: VCE Biology Question Thread
« Reply #218 on: January 13, 2014, 09:00:36 pm »
+1
Oh :P Now I get it haha! Cheers! So, would it be true to say that messages sent my these inhibitory neurotransmitters are of less importance; not that urgent?

Not at all. Brain activity is determined by circuits of neurones, not just individual neurones. So inhibitory neurones, very importantly, control the circuits. Failures in inhibitory neurones play a role in most mental illnesses and a number of neuronal diseases (as already mentioned by alon)
2013-15: BBiomed (Biochemistry and Molecular Biology), UniMelb
2016-20: MD, UniMelb
2019-20: MPH, UniMelb
2021-: GDipBiostat, USyd

Chang Feng

  • Victorian
  • Forum Obsessive
  • ***
  • Posts: 218
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #219 on: January 13, 2014, 10:13:00 pm »
0
heyy, just wondering if anyone knew if we need to know the specific types of bonds like peptide bonds. Because VCAA says this " The names for the specific types of bonds (for example, glycosidic, peptide) or bonding (for example hydrogen, covalent, disulfide) in carbohydrates, lipids, proteins and nucleic acids are not required." But during the 2014 unit 3 Biology summer lecture Mr Mac said we needed to know peptide bonds and some others also in the notes they provided us. So just confused if i need to know them or not. if you know???
thanks.

vox nihili

  • National Moderator
  • Great Wonder of ATAR Notes
  • *****
  • Posts: 5343
  • Respect: +1447
Re: VCE Biology Question Thread
« Reply #220 on: January 13, 2014, 10:31:01 pm »
0
heyy, just wondering if anyone knew if we need to know the specific types of bonds like peptide bonds. Because VCAA says this " The names for the specific types of bonds (for example, glycosidic, peptide) or bonding (for example hydrogen, covalent, disulfide) in carbohydrates, lipids, proteins and nucleic acids are not required." But during the 2014 unit 3 Biology summer lecture Mr Mac said we needed to know peptide bonds and some others also in the notes they provided us. So just confused if i need to know them or not. if you know???
thanks.

Despite TSFX's grandstanding, the VCAA do know their course better than them. Trust the VCAA :)
2013-15: BBiomed (Biochemistry and Molecular Biology), UniMelb
2016-20: MD, UniMelb
2019-20: MPH, UniMelb
2021-: GDipBiostat, USyd

RazzMeTazz

  • Victorian
  • Forum Leader
  • ****
  • Posts: 673
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #221 on: January 14, 2014, 09:22:41 am »
0
Hey guys,

Sorry I am not really sure in which thread this question belong, but I guess it relates to biology as well :)
This might sound silly, but when you have SAC's in your school, does the content on them have to relate to the content outlined in the area of studies?
Or is that only in the end-of-year exam?

thanks!

eagles

  • Victorian
  • Trendsetter
  • **
  • Posts: 140
  • Respect: +5
  • School Grad Year: 2014
Re: VCE Biology Question Thread
« Reply #222 on: January 14, 2014, 09:53:38 am »
0
School sacs vary from school to school and the degree of relevance to the VCAA study design is also different. While one school may go into more detail into photosynthesis than required by VCAA or test on irrelevant textbook material, you just need to follow what your school does to perform well on the SACs while throughout the year, concentrate on the checkpoints required by the VCAA study design for biology to ace the exam.

(On a note of certainty, the end-of-year exam relates is strictly limited to the official study design requirements. )

RazzMeTazz

  • Victorian
  • Forum Leader
  • ****
  • Posts: 673
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #223 on: January 14, 2014, 10:31:08 am »
0
School sacs vary from school to school and the degree of relevance to the VCAA study design is also different. While one school may go into more detail into photosynthesis than required by VCAA or test on irrelevant textbook material, you just need to follow what your school does to perform well on the SACs while throughout the year, concentrate on the checkpoints required by the VCAA study design for biology to ace the exam.

(On a note of certainty, the end-of-year exam relates is strictly limited to the official study design requirements. )

Oh okay thanks :)
I understand it now,!

RazzMeTazz

  • Victorian
  • Forum Leader
  • ****
  • Posts: 673
  • Respect: 0
Re: VCE Biology Question Thread
« Reply #224 on: January 14, 2014, 11:11:30 am »
0
Hi, I was wondering why does the rate of photorespiration in C3 plants increase at a higher temperature?
Is it because there is more light energy, so more ATP molecules and NADPH molecules are being formed in the light-dependent stage of photosynthesis, but in the Calvin-Benson cycle there is not enough carbon-dioxide molecules for them to 'fix' so once the carbon dioxide molecules run out, Rubisco starts to fix oxygen instead?

Thanks!