Biology Unit 3 Questions Megathread

[pi]

^That's it

Not a great question though, as the plant cell really doesn't retain its shape

Why are you doing bio at 7 (-ish) in the morning?

[WhoTookMyUsername]

Can you view vacuoles under LM?

[vexx]

Can you view vacuoles under LM?

light microscope?
We did an experiment where we could in a plant cell, some cells had the chloroplasts pushed against the cell wall because of a large bubble (vacuole) taking up so much room.

[HERculina]

Can you view vacuoles under LM?

ye i think you can for plants.

is chlorophyll a lipid?

[WhoTookMyUsername]

no chlorophyll is a pigment

[iNerd]

no chlorophyll is a pigment

That's y9! I actually understood one Q in this thread!

[shinny]

no chlorophyll is a pigment

Pigment's more of a functional description. In terms of biochemical, a quick Google search suggests it's technically actually a lipid because it's lipid-soluble. Not exactly required knowledge though.

[WhoTookMyUsername]

Intriguing! A pigment is not a chemical description but a tendency to change wavelengths into selective wavelengths, so all colour has some pigment!

[dooodyo]

Exactly how does the amino acid sequence of a polypeptide determine the final shape of the protein?

[HERculina]

well the amino acids each have an R group. an R group can determine wheter teh AA is polar, non-polar or charged. the bonds (disulfide bridge/ionic/H bonds) that form between the neighbouring AAs when they fold into its 3D structure are dependent on the R groups and their position in the sequence. for eg. a polar amino acid in one area of the sequence that formed a hydrogen bond with a another polar amino during the tertiary structure stage acid vs.  a charged aa forming an ionic bond with another charged amino acid
--> the shape and function would totally be different!

Intriguing! A pigment is not a chemical description but a tendency to change wavelengths into selective wavelengths, so all colour has some pigment!

i didnt noe that too! :O

This is the chlorophylls structure: a porphyrin ring (the head of the molecule with a central mg ion) attached to a hydrocarbon tail (interacts with hydrophobic regions of proteins in the thylakoid membrane)

[WhoTookMyUsername]

lol and you DEFINATELY do not need to know that

[HERculina]

are transition reactions part of the Krebs cycle?

[vexx]

are transition reactions part of the Krebs cycle?

by transition it indicates the reactions before Krebs and after glycolysis. so converting the products of glycolysis to the form used at the start krebs cycle (pretty sure its Acetyl CoA)

[HERculina]

The efficient folding of a protein molecule is ensured by the presence of other proteins known as protein chaperons in a cell. A likely result of defective chaperone is:
a)the production of a protein with a faulty primary structure
b)the production of proteins with incomplete tertiary structures
c)the production of a protein with a faulty secondary structure
d)the overproduction of the protein

[WhoTookMyUsername]

Answer is B

Doubt they would ask that on exam as it is very indepth knowledge, but it could be one of the harder MC on there