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Please help with my work

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Please help with my work

Postby Olympic » Mon Jul 23, 2012 2:17 pm

Hi everyone,

I'd really appreciate it if someone could help me with these questions. I've only just took up Biology so it's all a but daunting at the moment. Thanks in advance for any help.

1)Why is fat used for long term energy storage, especially in animals?

Ans; maybe cos they insulate and form membranes?

2 A) Describe how you would test for milk for the presence of fat?
B) What observation indicates a positive result?

Ans; Would this be putting milk on brown paper, then on radiator and if it presents
A perm stain it contains fat.

3) Water is a (good absorber of energy) which helps it to maintain a ( stable temperature). This affects entire ( organisms) and ( metabolic reactions)

3a Explain the words in the brackets.

Ans; good absorber of energy - it is slow to heat up and slow to cool down.
Stable temperature -the high water content of organisms helps to keep their temperature stable
Organisms - living things
Metabolic reactions - the sum of all chemical reactions in an organism.

3b in what way are 'entire organisms' and ' metabolic reactions ' affected by water being a good absorber of energy?

Ans; Not sure on this one.

4. Say whether the following statements are true or false. In the case of a false statement, give a reason why it is false.

a) Carbohydrates contain hydrogen and oxygen in the same ratio as water ( H20).
b) Amino acids do not contain nitrogen
c) Fish is a good source of protein and lipid,but not carbohydrate.
d) Keratin is a protein found in egg white
e) Amino acids are required to make fatty acids
f) The biuret test indicates the presence of proteins
g) Chewing food is an example of anabolism

A) False in carbohydrate there is always twice as much hydrogen as oxygen
B)f they contain nitrogen
D) True
E) True

5. Name two minerals required by the human body
Ans; Water and Sodium

In the case of these minerals state it's function in the body.

Ans; Water- good absorber of heat in the body
Sodium- they play a role in forming cell and body fluids - tears , saliva and the liquid part of blood all contain sodium.
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Postby Darby » Tue Jul 24, 2012 2:20 pm

These are terrible questions - whoever wrote them hasn't thought them through.

There are a bunch of possible answers to the first one, but yours isn't.

The second one looks fine.

The third one - that property of water affects aquatic ecosystems, but in anything but very large organisms, it's pretty irrelevant.

4 - a only applies to simple carbs, but who knows what they're looking for?
b is right, c you can look up, d you need to double-check, e depends on how bizarrely you interpret the question, but could be true or false, f you've got, and g you can look up

5 - make sure you know what a mineral is, and you've given locations for sodium but not a function.
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Re: Please help with my work

Postby Olympic » Tue Jul 24, 2012 6:47 pm

Thanks a million for your help. Have attempting a few more and the incorrect ones.

1. fats contain more energy than carbohydrates do, because fat molecules are chemically much more reduced 

4c  False  if carbohydrate supply is very low, the body will automatically use your proteins  as an energy source. 

4d. False found in membrane not yolk

4g False an example of anabolism is the formation of muscle proteins from amino acids.

5 Sodium and Calcium

Calcium- needed to maintain strong and healthy bones and teeth. It is also involved in normal blood clotting, muscle and nerve function.

Sodium -  Helps to maintain muscles and nerves in good working order and works together with potassium, regulating the fluids in the body. 
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Postby JackBean » Wed Jul 25, 2012 6:30 am

1. you second answer is correct (plus they are hydrophobic)

3. a high heat capacity; doesn't change much;
b on the microscale the water may buffer changes in temperature due to exo-/endothermic reactions

a as long as we are not talking about some aminosugars, it's true
b definitely not true! Why? That's like saying Car does not have wheels. If not, why?
c I guess yes (you're not answering that at all)
d F Why? Because it's not expressed there. (but it's not in membrane either :roll:)
e sure, the amino acids are required to build proteins which catalyze the biosynthesis of fatty acids

Cis or trans? That's what matters.
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Postby Olympic » Wed Jul 25, 2012 2:05 pm

Thanks guys

Is 4g correct?
4d false as it not expressed there as you said, expressed in epithelial cells?
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Postby Darby » Thu Jul 26, 2012 11:56 am

You're not always following your instructions - instead of stating why something is false, you're just giving some sort of related truism.
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Postby Olympic » Thu Jul 26, 2012 4:22 pm

4G False
Chewing is catabolic and physically breaks up the food.

Sorry about mix up in answers. Find some of the subject v difficult.
Just need more work and I'll get there!
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