Biology Unit 3 Questions Megathread

[WhoTookMyUsername]

What effect does Cholesterol have on the Cell membrane? Douchy said it was to add stability and rigidity but elsewhere it says to add fluidity?

[shinny]

What effect does Cholesterol have on the Cell membrane? Douchy said it was to add stability and rigidity but elsewhere it says to add fluidity?

I would have said fluidity.

[Russ]

At low temperatures it keeps the membranes fluid and prevents them from crystallizing but it also has other important structural functions

[WhoTookMyUsername]

At low temperatures it keeps the membranes fluid and prevents them from crystallizing but it also has other important structural functions

Such as?...

also

1 ) Do things like penicillin also prevent cell wall synthesis in plants? (are the enzymes they block common ?)

2 ) Are all poisons non - competitive inhibitors ? (poison must have permanent bond???)

3 ) Is Cysteine very common in proteins ? ( is it in most ? douchy said that i think )

4 ) IS a better defintion of a Organic compound Carbon and Hydrogen or Carbon containing excluding carbonides etc...

5 ) Are things like Oxygen Gas molecules ? (according to douchy must have more than one different element covalently bonded ) if not, what are they called

6 ) Does water soluble refer to the complete breakdown of the molecular compound / molecule structure (e.g. NaCl -> Na + Cl) and/or the tendency for substances to seperate into individual, unconnected parts in water (e.g. full glucose molecule). Does it depend on Ionic / Covalent bonds?

7 ) Does plasma membrane refer to any phospholipid bilayer?

8 ) NOB says some enzymes work by lock and key and others by induced fit, biozone states Induced fit is the current model, which is correct?

9) Are all Antibodies Proteins?

10) Can some RNA act as enzymes?

11 ) Does denaturation change Secondary and/or teritiary, or tertiary and/or quartenary structure?

Russ: Post new questions in a new post, only edit an old post if nobody has replied yet

[pi]

I'll help with the ones I remember:

3) Not on the course, there is no need to know this.

4) I would just say an organic compound is one that contains a 'backbone' of covalently bonded carbon atoms.

5) Oxygen gas is simply known as oxygen, and many consider it an 'element' and it is made up of only one type of atom (0₂). Like N₂ (nitrogen gas), He (helium gas), C (diamond).

6) The first part of your question is wrong. NaCl is not a molecule. But the process described is dissociation of ionic compounds (not all are soluble). Water is hence, able to overcome ionic bonds in some ionic compounds. Solubility also refers to polar substances (molecules) that are able to form hydrogen bonds with the polar water molecules.


Don't remember 1) and 2)...

[Russ]

1 ) Do things like penicillin also prevent cell wall synthesis in plants? (are the enzymes they block common ?)

Penicillin targets peptidoglycan, which isn't present in plant cells.

2 ) Are all poisons non - competitive inhibitors ? (poison must have permanent bond???)

No (there are very few absolute statements in biology)

5 ) Are things like Oxygen Gas molecules ? (according to douchy must have more than one different element covalently bonded ) if not, what are they called

Yes (both by the chemistry definition and the biology definition)

7 ) Does plasma membrane refer to any phospholipid bilayer?

Yes, but I guess you could apply it to a monolayer/non phospholipid bilayer

8 ) NOB says some enzymes work by lock and key and others by induced fit, biozone states Induced fit is the current model, which is correct?

Induced fit is more correct than lock and key (at VCE it doesn't matter imo)

[pi]

9) Are all Antibodies Proteins?

Yes, they are those Y-shaped proteins

10) Can some RNA act as enzymes?

Yes, they are ribozymes (not in the course)

[pi]

11 ) Does denaturation change Secondary and/or teritiary, or tertiary and/or quartenary structure?

It denatures the secondary and tertiary structures (hence denaturing the quaternary structures if the protein has one).

Russ: Post new questions in a new post, only edit an old post if nobody has replied yet

+1, only saw the last few by luck

[WhoTookMyUsername]

What are the two major functions of monosaccharides:
1) Immediate energy source
2) ? ( monomer of polysaccharides? )

[dooodyo]

I would say that they are an immediate soruce of chemical energy for cellular functions/ respiration.

[Russ]

Structural is the first thing that jumps to mind

[TrueLight]

9) Are all Antibodies Proteins?

Yes, they are those Y-shaped proteins

10) Can some RNA act as enzymes?

Yes, they are ribozymes (not in the course)

pfft they arent all Y shaped lol

[WhoTookMyUsername]

Structural is the first thing that jumps to mind

Thought they have to be polysacchardies for structural?

9) Are all Antibodies Proteins?

Yes, they are those Y-shaped proteins

10) Can some RNA act as enzymes?

Yes, they are ribozymes (not in the course)

pfft they arent all Y shaped lol

What is an example of non Y shape?

[TrueLight]

IgM, IgA

[WhoTookMyUsername]

Quote from: Russ on Today at 11:37:10 AM
At low temperatures it keeps the membranes fluid and prevents them from crystallizing but it also has other important structural functions
Such as?... 

also

1 ) Do things like penicillin also prevent cell wall synthesis in plants? (are the enzymes they block common ?)

2 ) Are all poisons non - competitive inhibitors ? (poison must have permanent bond???)

3 ) Is Cysteine very common in proteins ? ( is it in most ? douchy said that i think )

4 ) IS a better defintion of a Organic compound Carbon and Hydrogen or Carbon containing excluding carbonides etc...

5 ) Are things like Oxygen Gas molecules ? (according to douchy must have more than one different element covalently bonded ) if not, what are they called

6 ) Does water soluble refer to the complete breakdown of the molecular compound / molecule structure (e.g. NaCl -> Na + Cl) and/or the tendency for substances to seperate into individual, unconnected parts in water (e.g. full glucose molecule). Does it depend on Ionic / Covalent bonds?

7 ) Does plasma membrane refer to any phospholipid bilayer?

8 ) NOB says some enzymes work by lock and key and others by induced fit, biozone states Induced fit is the current model, which is correct?

9) Are all Antibodies Proteins?

10) Can some RNA act as enzymes?

11 ) Does denaturation change Secondary and/or teritiary, or tertiary and/or quartenary structure?

What are the two major functions of monosaccharides:
1) Immediate energy source
2) ? ( monomer of polysaccharides? )