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AP®︎/College Biology
Unit 1: Lesson 4
Properties, structure, and function of biological macromolecules- Molecular structure of DNA
- Antiparallel structure of DNA strands
- Molecular structure of RNA
- Introduction to amino acids
- Overview of protein structure
- Introduction to carbohydrates
- Carbohydrates
- Molecular structure of triglycerides (fats)
- Saturated fats, unsaturated fats, and trans fats
- Biological macromolecules review
- Properties, structure, and function of 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?
how can lipids act as a chemical messenger?(5 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.(11 votes)
Are phospholipids polymers?(3 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(6 votes)
why are vitamins not digested in the body(5 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.(2 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(4 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!(3 votes)
is amino acids used in protein shake(2 votes)
unfortunately, yes.(2 votes)
Why aren't minerals a macromolecule?(2 votes)- Macromolecules Have different structures and characteristics than minerals. minerals are also single elements. Macromolecules are different atoms and elements COMBINED. I totally see your confusion and hope that this helps you.(5 votes)
- 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?(2 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!(3 votes)
When the body doesn't have any lipids or carbs for energy, does the body use protein as a last resort or when is protein used? After a workout when you don't eat? I'm just curious.(2 votes)
Protein is indeed used like a last resort! After carbs are completely depleted, the body will switch to fatty acids as the main energy source, powering essential body systems like the nervous and circulatory systems. If the body is left like this for several days, cells will begin to break down protein in conjunction with the fat. This is dangerous in the long run, especially if the fat storages are completely used up, as the loss of proteins cause organ damage. When this protein breakdown occurs and when it will become fatal, however, depends on the person.
As starvation typically happens over the period of several days, the body does not have to use many--if any--proteins to power itself should you skip a meal on purpose every day. Here, you might be breaking fat instead. However, every person is different, and one diet plan or fasting regimen can have vastly different effects on a person.
Did this help, and was I clear?(3 votes)
Which biological molecule is made up of nucleotides?(2 votes)
Nucleic acids are made up of nucleotides. Nucleic acids are used to store and pass on heritable traits through genetic information, basically a blueprint on how to make a human, through DNA and RNA. Hope this helps!(3 votes)
hi
can someone give me the basic idea of how nucleic acids end up being instructions for how we look our height and ... ?(3 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.(1 vote)