Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Basics for: Carbohydrates, Proteins, Amino Acids and Lipids

  1. Feb 7, 2015 #1
    I have been trying to get my head around the basics for these four (Carbohydrates, Proteins, Amino Acids and Lipids) for about a week and I just don't understand the basic structure, formulas and such. Help?!
  2. jcsd
  3. Feb 7, 2015 #2


    User Avatar
    Homework Helper
    Gold Member

    Wonder whether we can. We deal with comprehension problems and questions arising from textbooks and excercises, we don't write the textbooks.
    How much chemistry have you done? If you don't know any, if you haven't done/remember alcohols, amines and so on one chemical formula will look much of a muchness with any other.

    You say amino acids and proteins. You do understand the relation between these?

    Now I'm thinking what else I can suggest. By the sound of it the problem is (if I'm right you wouldn't be the only one) - it is totally boring, but it is boring because you are studying it in a boring, passive, unenterprising way. You have this heavy book that looks and feels like it was made of lead, and you are boringly learning a series of meaningless structures from lists.

    But proteins are not boring, they are the most fantastically, well, protean molecules on earth and possibly anywhere else! Magic and the secret of life! They are interesting for what they do. The most important thing they do, enzymic catalysis, depends on the chemistry of their side chains. So you have to know the chemical nature of these. Serine has a different chemical properties from histidine or leucine.

    So the first thing to focus is the chemical nature of the groups on the side chains. If you remember nothing alcohols (ser and thre) sulphydryls (cys) amines (lys and N-terminals), carboxylic acids, amides, paraffins rapidly refresh them. And anything you hit on for the more oddball ones. You'll need to know how they're ionised or not at neutral pH. Then rapIdly move on to tertiary structure (the 3-D folding of the chain) in connection with some functions asap.

    So know the peptide bond structure, the chemical types of side chain, with a name to which aa falls in each type. Knowing how many carbon atoms the side chain of leucine or lysine etc. have is rubbish, I don't remember for certain. Take it in once and then mug it up any time you are going to be tested on it. Then get on to how they typically interact with each other and how the peptide bond folds and how proteins fold and how this makes them work and some examples of them working. I don't have any of the right books, someone else may suggest, but you could browse your uni bookshop, or Amazon etc. for a book on protein structure and function. You need one with good pics but you don't need the latest edition so you could get cheap.
    Some of this may be in later chapters of the book you are using. And any enzyme or other protein you come across, you can look it up on Internet. There is probably a structure and explanations for it there; you may not understand or remember everything, but it will all help you focus better when it comes in the course.

    In case a good book is slow to find you can more easily find one on how proteins are made in the living cell. This is fundamental and interesting molecular biology you need anyway, and another secret of life. Then you'll at least see plenty of examples of enzymic reactions if not how they work. If you do carbohydrates, similarly look at their biosynthesis at the same time as their structure. Before the proteins are synthesised from aminoacids the aminoacids have to be biosynthesised too. That I'd call uh-huh so-so interesting, but there are plenty of typical biochemical reactions in that too amd may be in your syllabus.

    IOW it sounds like your course designers have decided 'they have learn this before we can get them on to that', and IMO that is a mistake, and you have to try run a bit before you walk. It's harder work but better than sitting there with 2 leaden kilos of book.
    Last edited: Feb 8, 2015
  4. Feb 9, 2015 #3
    I'm taking Biology and we have this section of Biochem and I'm so confused!
    Thank you for your help!
  5. Feb 9, 2015 #4


    User Avatar
    Homework Helper
    Gold Member

    Good luck. To summarise all that, I reccomend not staying stuck on your chapter only but ranging forward in your book and other sources to see what these structures do in life (and backwards to any necessary chemistry if hazy) would not only stimulate learning the present chapter, but help when you come again to the future ones later. Right now it could be easier to take in a part of this future stuff just because you yet don't have to, so you are not stressed about how well you do it , yet it will make it easier later.
  6. Feb 12, 2015 #5
    Carbohydrates - made of Carbon, Hydrogen and Oxygen. Used by body for energy.

    Proteins - made mainly of Carbon, Nitrogen, Hydrogen, Oxygen and a bit of Sulphur. Made only of amino acids. Make up structure of your body. Can be used for energy.

    Amino Acids - made of the same elements as protein (as they are the assembly blocks of proteins). Think of them as sub-proteins.

    Lipids - no idea, but are basically just fats/oils.
  7. Feb 13, 2015 #6
    1)Carbohydrates are made of either different kind of Hexoses (6 carbon) cross linked to each other.The basic Hexose may be Glucose or fructose or Galactose etc linked to each other making them Di-saccharides.Basically starch and cellulose is made of glucose cross linking all along.(There are different linkages). You basically see no other metal involvement here except C,H,O.So carbohydrate is train of mono-saccharides.
    2)On the other hand proteins are formed by Aminoacid linkages making them assume different structures based on interactions between Aminoacids.So Protein is a big band of AMINOACIDS.
    3)Lipids are really a very wide class of molecules ranging from fats,vitamins,sterols etc.Really have no basic format to mention here. You can just say it when you see it.
    Hope it helps.cheers.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook