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High school biology
Course: High school biology > Unit 1
Lesson 2: Important molecules for biology- Elements and atoms
- Introduction to carbohydrates
- Introduction to proteins and amino acids
- Introduction to lipids
- Introduction to nucleic acids and nucleotides
- Introduction to vitamins and minerals
- Biological macromolecules review
- Biological macromolecules
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Biological macromolecules review
AP.BIO:
SYI‑1 (EU)
, SYI‑1.B (LO)
, SYI‑1.B.2 (EK)
, SYI‑1.C (LO)
, SYI‑1.C.1 (EK)
Key terms
| Term | Meaning | |
|---|---|---|
| Biological macromolecule | A large, organic molecule such as carbohydrates, lipids, proteins, and nucleic acids. | |
| Monomer | A molecule that is a building block for larger molecules (polymers). For example, an amino acid acts as the building blocks for proteins. | |
| Polymer | A large molecule made of repeating subunits (monomers). For example, a carbohydrate is a polymer that is made of repeating monosaccharides. |
Types of biological macromolecules
| Biological macromolecule | Building blocks | Functions | Examples |
|---|---|---|---|
| Carbohydrates | Monosaccharides (simple sugars) | Provide cells with quick/short-term energy, source of dietary fiber | Glucose, sucrose, starch, cellulose, chitin |
| Lipids | Fatty acids and glycerol | Provide cells with long-term energy, make up biological membranes | Fats, phospholipids, waxes, oils, grease, steroids |
| Proteins | Amino acids | Provide cell structure, send chemical signals, speed up chemical reactions, etc | Keratin (found in hair and nails), hormones, enzymes, antibodies |
| Nucleic acids | Nucleotides | Store and pass on genetic information | DNA, RNA |
Common mistakes and misconceptions
- Describing macromolecules as “large” is relative. We refer to them as “macro” because they are large compared to other, smaller molecules. However, this does not mean that they are large enough to view with the naked eye. Even a large protein, like hemoglobin, is still a million times smaller than a grain of rice!
- Not all fats and carbohydrates are “bad.” Information about different kinds of diets can be confusing and may lead someone to believe that all fats or all carbohydrates are unhealthy. This simply isn’t the case. Fats and carbohydrates are actually essential for cellular function!
Want to join the conversation?
After reading the key terms, I am a little bit confused.. to my understanding, monomers are the makeup of polymers... is that correct? If so, are the terms "polymer" and "biological macromolecules" synonymous?(44 votes)
Hello,
As I understand it, polymers are a subdivision of biological macromolecules. 'Polymer' is the branch of macromolecules that is made up of ONLY ONE monomer that repeats itself.
For example, a carbohydrate is a macromolecule that is classified as a polymer because it is made up of repeating monosaccharides, but a fat (lipid) is a macromolecule that cannot be further classified because if you look under the 'monomers' column, it is built up by more than one monomer.
Hope this helped!(101 votes)
Isn't protein an energy molecule for muscles?(12 votes)
Rather than providing energy for muscles, they are structural components, which means they build and repair muscles. Protein is only used as energy if carbohydrates and lipids aren't available for energy (side note: breaking down protein for energy is unhealthy and dangerous!).
Hope this helps, - Layla(41 votes)
how can lipids act as a chemical messenger?(9 votes)
Some lipids such as steroid hormones serve as chemical messengers between cells, tissues, and organs, and others communicate signals between biochemical systems within a single cell.(15 votes)
Are phospholipids polymers?(11 votes)- There is considerable interest in the polymers bearing phospholipids in the main chains as the structures of these polymers are similar to biological tissues. Several polymers containing a phospholipid in the polymer backbone have been synthesized and characterized(8 votes)
Why aren't minerals a macromolecule?(6 votes)
What are the characteristics of a macromolecule?
Can you think of a mineral that meets all those criteria?
Does that help you to answer your question?(7 votes)
- which would be the differences between DNA and RNA were not very clear to me, they seem technically the same and I cannot differentiate them very well(5 votes)
If you are asking what the difference between the two is, here you go.
There are several differences. To start, DNA stands for deoxyribonucleic acid, while RNA stands for ribonucleic acid. These names describe the sugar that makes up their backbone--DNA = deoxyribose and RNA = ribose.
Second, while each has four nucleiotide bases, there is one difference. You probably know that DNA has guanine, cytosine, adenine, and thymine, and that guanine links to cytosine and adenine links to thymine. But RNA doesn't have thymine. Instead, it has uracil, a nucleiotide base with a slightly different chemical makeup. Thymine had the chemical formula C5H6N2O2 and uracil is C4H4N2O2. Uracil links to adenine in RNA just like thymine does in DNA
Finally, DNA is double-stranded and forms a double helix structure. RNA is single-stranded and is generally straight. DNA is a complete set of instructions needed for life (unless you're a virus, but that's a whole different story/debate) and RNA is used to copy DNA and to synthesize proteins. I know this is a lot to take in, but there are several videos and articles on Khan Academy to help. Here are a few.
https://www.khanacademy.org/science/high-school-biology/hs-molecular-genetics/hs-rna-and-protein-synthesis/v/molecular-structure-of-rna
https://www.khanacademy.org/science/high-school-biology/hs-molecular-genetics/hs-rna-and-protein-synthesis/v/rna-transcription-and-translation
https://www.khanacademy.org/science/high-school-biology/hs-molecular-genetics/hs-rna-and-protein-synthesis/a/hs-rna-and-protein-synthesis-review
Anyway, this is probably a lot, but I hope it helps!(11 votes)
Are monomers and monosacchrides the same thing? Also, what is a polypeptide?(7 votes)
Monomers are the building blocks of the four basic macromolecules of life- monosaccharides are the monomers of carbohydrates, amino acids are the monomers of proteins, glycerol/fatty acids are the monomers of lipids, and nucleotides are the monomers of DNA.
Polypeptides consist of a bunch of amino acids bound together- so in a way it's a monomer of proteins!(6 votes)
- why are vitamins not digested in the body(6 votes)
Vitamins are not digested, whereas, they are absorbed.
Vitamins are organic compounds that are required for normal animal metabolism but are either not created in the body or are created in insufficient amounts and must be received through your diet. Almost all of vitamin absorption goes to the small intestine.
Vitamin absorption in the intestine is important for avoiding deficiency disorders, and it can be limited by a variety of factors, including intestinal disease, genetic abnormalities in transport molecules, excessive alcohol use, and drug interactions.(7 votes)
hi
can someone give me the basic idea of how nucleic acids end up being instructions for how we look our height and ... ?(4 votes)
Hey!
So basically nucleic acids are different structures that form long strands of DNA or RNA, which is our genetic code basically. These nucleic acids form what are called nucleotides, which then form the DNA and RNA.
Nucleic acids are found in every living thing, from bacteria to viruses (though there is still a debate as to whether viruses are living or not).
I hope this answered your question.(6 votes)
Does anyone know how to pronounce DNA in word form?(4 votes)- DNA:
deoxyribonucleic acid. dee-OCK-see-RY-boh-noo-KLAY-ik A-sid.(3 votes)