quick question

[hard]

amm well i'm studying carbohydrates right now and i've come across a dot point on the vcaa bio study guide. It goes you need to know the synthesis of biomacromolecules: polysaccharides, nucliec acid and i think the other one was lipids. However i'm not too sure what they're asking.
Do they want you to know the chemical mixture of such compounds? Also there are three saccharides states in the book including monosaccharide, disaccharide and polysaccharide. Why does it only say polysaccharide in the study design?   

Do they just want you to know about polysaccharides because they're made up of many monosaccharides? And do we have to know examples of 'em?

[hard]

one more question:

why do humans get little energy from lettuce?

what could potentially be my answer is this:

Lettuce contains cellulose, a polysaccharide. Essentially, cellulose does not provide much nutrients for humans due to the fact that humans do not have the required enzymes to break it down. Thus, by not being able to be broken down into smaller chemical structures, lettuce provides little energy for the average human.

not sure on the answer though.

[hard]

can someone answer please.

[shinny]

one more question:

why do humans get little energy from lettuce?

what could potentially be my answer is this:

Lettuce contains cellulose, a polysaccharide. Essentially, cellulose does not provide much nutrients for humans due to the fact that humans do not have the required enzymes to break it down. Thus, by not being able to be broken down into smaller chemical structures, lettuce provides little energy for the average human.

not sure on the answer though.

Correcto.

[hard]

one more question:

why do humans get little energy from lettuce?

what could potentially be my answer is this:

Lettuce contains cellulose, a polysaccharide. Essentially, cellulose does not provide much nutrients for humans due to the fact that humans do not have the required enzymes to break it down. Thus, by not being able to be broken down into smaller chemical structures, lettuce provides little energy for the average human.

not sure on the answer though.

Correcto.

oh you legennnnnd thanks man.

[Toothpaste]

amm well i'm studying carbohydrates right now and i've come across a dot point on the vcaa bio study guide. It goes you need to know the synthesis of biomacromolecules: polysaccharides, nucliec acid and i think the other one was lipids. However i'm not too sure what they're asking.
Do they want you to know the chemical mixture of such compounds? Also there are three saccharides states in the book including monosaccharide, disaccharide and polysaccharide. Why does it only say polysaccharide in the study design?  

Do they just want you to know about polysaccharides because they're made up of many monosaccharides? And do we have to know examples of 'em?

Examples, yes.

Chitin, starch, cellulose, glycogen, etc.

Also good to know what's so special about each, where they're found, function ... etc
eg; Chitin is a polysaccharide found in the exoskeleton of certain insects (i.e. beetles)
Cellulose = plant cell walls

glycogen = energy storage in animal cells (espesh liver and muscles)
starch = energy storage in plant cells

(side info: recall anerobic cellular respiration (with oxygen) which uses the glucose molecules after they're broken down
(+ ATP))   explains the energy storage thing


I think they asked for an example of a certain type of protein (fibrous?) in the 08 unit 3 exam (collagen, fibrin were correct). So yeah, 'tis good to have examples handy.

EDIT: it only says polysaccharide because that's the biomacromolecule (big!) made from; mono, di

[hard]

amm well i'm studying carbohydrates right now and i've come across a dot point on the vcaa bio study guide. It goes you need to know the synthesis of biomacromolecules: polysaccharides, nucliec acid and i think the other one was lipids. However i'm not too sure what they're asking.
Do they want you to know the chemical mixture of such compounds? Also there are three saccharides states in the book including monosaccharide, disaccharide and polysaccharide. Why does it only say polysaccharide in the study design?  

Do they just want you to know about polysaccharides because they're made up of many monosaccharides? And do we have to know examples of 'em?

Examples, yes.

Chitin, starch, cellulose, glycogen, etc.

Also good to know what's so special about each, where they're found, function ... etc
eg; Chitin is a polysaccharide found in the exoskeleton of certain insects (i.e. beetles)
Cellulose = plant cell walls

glycogen = energy storage in animal cells (espesh liver and muscles)
starch = energy storage in plant cells

(side info: recall anerobic cellular respiration (with oxygen) which uses the glucose molecules after they're broken down
(+ ATP))   explains the energy storage thing


I think they asked for an example of a certain type of protein (fibrous?) in the 08 unit 3 exam (collagen, fibrin were correct). So yeah, 'tis good to have examples handy.

ahkai thanks toothpick

[Hielly]

hrmm i also came acrosee that dotpoint that hard mentioned,
-synthesis of biomacromolecules:polysaccharides,nucleic acids and proteins.

So as toothpick mentioned the polysaccharides one. Can someone explain further on the others?

thanks

[Toothpaste]

Sorry I'm going to be lazy and printscreen stuff.

Nucleic acid ... DNA, RNA (mRNA, tRNA, rRNA ...)
Monomer of nucleic acids = nucleotides (the phosphate, sugar and nitrogenous base combo)
Picture from NoB2:




Amino acids are the monomers of Proteins.
It's good to know examples for proteins (i.e. structural, transport etc as shown:)

Last year's exam:
Keratin, found in fingernails and claws, is an example of a fibrous protein.
d. Name another example of a fibrous protein and briefly outline its function.
This ruled keratin out. So if you didn't have a back up protein you were screwed. I wrote fibrin because fibrous.. = fibrin lol.
From the report:
Any one of:
•collagen, to provide strength to skin
•fibrin, required for blood clotting
•myosin, to facilitate muscle contraction.




You'll also need to know the levels of structures of proteins.
Primary, secondary, tertiary, quarternary.




You'll also have to know the difference between Beta-pleated sheets and Alpha helices. (2nd)



http://www.vcaa.vic.edu.au/vce/studies/biology/pastexams/2008/2008biol1-web.pdf
Question 2 short answers gives you things to expect to do with this topic!

[hard]

can someone show me how i would do this:

devise a simple diagram that compares the structural polysaccharides that make up the cell walls of plants and fungi.

do we have to know how to draw such diagrams?

[beezy4eva]

Plant cell walls are made of cellulose, fungi walls are chitin. Just do a little table or something with dotpoints about the differences and similarities of the two chemicals.

[hard]

Plant cell walls are made of cellulose, fungi walls are chitin. Just do a little table or something with dotpoints about the differences and similarities of the two chemicals.

yer i write that but i got confused by what they were trying to ask. well anyway ill just do what you said.

[hard]

okay neq question:

Relate the structure of lipid molecules to their function.

Answer:

Lipids are classified based on their solubility. This is dependent on two factors: the shape of the molecule and the nature of their intramolecular bonds.
Essentially, lipids have three major functions; i.e. they are energy storers, they are structural components of membranes and they provide a means for specific biological functions such as communication.
It may be noted that most fats and oils of plants and animals are mostly made up of triglyceride molecules. These are basically three fatty acid attached to a glycerol backbone.
Going back to the first feature of lipids being that they sotre energey; fats in animals are saturated. This means that the carbons atoms have only single straight bonds allowing for them to pack closely and form a solid. This is a common mechanism used by many animals such as polar bears to 'store energy' and heat in harsh conditions, or blubber in whales.

from here i'm stuck. not sure whether i should mention phosphophlipids or glycoplipids or cholostrol or whether it has answered the question. can someone help please?

[hard]

bump//

[hard]

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