Hi, I'm Cathy with Level Up RN. In this video, I'm going to continue my coverage of topics from our Level Up RN Microbiology Flashcards.
Specifically, I'll be reviewing the different macromolecules, including proteins, carbohydrates, lipids, and nucleic acids.
At the end of the video, I'm going to give you guys a quiz to test your understanding of some of the key facts I'll be covering, so definitely stay tuned for that. And if you have our Level Up RN Microbiology Flashcards, go ahead and pull out your flashcards so you can follow along with me.
First up, let's talk about protein. Proteins are essential for many functions in the body. They serve as enzymes, hormones, and antibodies, they provide structural support for cells, and they are involved in the transport and storage of substances throughout the body.
Proteins consist of long chains of amino acids, and each amino acid consists of a hydrogen atom, a carboxyl group, an amino group, and a side chain, which is also referred to as an R group.
There are 20 different amino acids, and they all have the same hydrogen atom, carboxyl group, and amino group, but the side chain or R group will vary across the different amino acids.
Protein structure is categorized into four levels: primary, secondary, tertiary, and quaternary.
The primary structure is a sequence of amino acids linked together to form a polypeptide chain.
The secondary structure is the folding of that polypeptide chain into alpha helices or beta-pleated sheets. This occurs due to hydrogen bonding between the carboxyl group on one amino acid to the amino group of another amino acid.
The tertiary structure is the three-dimensional shape that takes place due to interactions between the side chains in the polypeptide.
And then finally, the quaternary structure forms when there are side chain interactions between two or more polypeptides. So only some proteins have a quaternary structure.
One example is hemoglobin, which consists of four polypeptides.
Now let's talk about carbohydrates. Carbohydrates are essential for energy production and energy storage in the body. They also provide structural support in cell walls and are key components in DNA and RNA.
Carbohydrates consist of carbon, hydrogen, and oxygen atoms present in a 1-2-1 ratio, which means for every carbon atom, there will be two hydrogen atoms and one oxygen atom.
Monosaccharides are the simplest carbohydrates, and they are the building blocks for more complex carbohydrates.
Examples of monosaccharides include glucose and fructose.
Disaccharides are formed when two monosaccharides are bonded together.
Examples of disaccharides include sucrose and lactose.
And then polysaccharides are chains of hundreds of monosaccharides bonded together.
Examples of polysaccharides include starch, glycogen, cellulose, and chitin.
Now let's talk about lipids, which include a lot of different molecules that are hydrophobic or water fearing. So lipids are primarily composed of carbon and hydrogen.
They're essential for energy storage, hormone synthesis, insulation in the body, and they're a key component of cell membranes.
Fatty acids are one type of lipid. A fatty acid is composed of a long chain of hydrocarbons with a carboxylic acid functional group at the end.
Unsaturated fatty acids contain hydrocarbon chains with at least one double bond.
Unsaturated fatty acids are typically liquid at room temperature.
Saturated fatty acids contain hydrocarbon chains with all single bonds. Because these type of fatty acids contain the maximum number of hydrogen atoms, they are considered saturated with hydrogen.
Saturated fatty acids are typically solid at room temperature.
Triglycerides are another type of lipid. They are composed of three fatty acids linked to a glycerol molecule.
Phospholipids are also lipids. They contain a hydrophilic region that contains a phosphate group and a glycerol in a hydrophobic region that contains two fatty acids, and we will definitely be talking about phospholipids more when we discuss cell membranes.
And then sterols are lipids as well. Sterols are complex ringed molecules that strengthen cell membranes.
Examples of sterols include cholesterol, as well as hormones such as testosterone and estrogen.
The last macromolecule that we're going to talk about are nucleic acids, which are composed of long chains of nucleotides. DNA and RNA are the two key types of nucleic acids.
DNA is a double-stranded molecule that serves as the genetic material for all living organisms, and RNA is a single-stranded molecule that is essential in protein synthesis.
Each nucleotide consists of a five-carbon sugar, a phosphate group, and a nitrogenous base.
In DNA, the five-carbon sugar is deoxyribose, and the nitrogenous bases include adenine, guanine, cytosine, and thymine.
In RNA, the five-carbon sugar is ribose, and the nitrogenous bases are the same as DNA, except for uracil replaces thymine.
So we will definitely be talking a lot more about DNA and RNA in this playlist, so it's important to understand the structure of these nucleic acids.
All right. It's quiz time, and I have seven questions for you.
Question number one.
A blank is a chain of hundreds of monosaccharides bonded together.
The answer is...a polysaccharide.
Number two.
Proteins consist of long chains of blank.
The answer is...amino acids.
Number three.
What protein structure is characterized by the folding of the polypeptide chain into alpha helices or beta-pleated sheets?
The answer is...the secondary structure.
Number four.
What are the two main types of nucleic acids?
The answer is...DNA and RNA.
Number five.
Nucleic acids are composed of long chains of blank.
The answer is...nucleotides.
Number six.
Are lipids hydrophilic or hydrophobic?
The answer is...hydrophobic.
And last question.
What type of fatty acid contains hydrocarbon chains with at least one double bond?
The answer is...unsaturated fatty acids.
All right. That's it for this video. I hope you did great with that quiz, and I hope you found this video to be helpful. Take care and good luck with studying.
[BLOOPERS]
Unsaturated fatty acids [condain?]-- when there are side chain interactions between two or more polypeptides. So only some-- oh my God. Why is it doing that? Oh, I've got confetti now. So one is, yeah, that's blue. How am I supposed to hold up two fingers without this happening? Yay.
