Proteins are one of the most influential macromolecules, and almost all aspects of life involve their use. Proteins are able to carry out specified cellular functions; some catalyze chemical reactions needed to maintain life while others are used for signaling or to coordinate internal cell activities or inter-cellular communication. Proteins are able to form large organic molecules because they are polymers, which are large molecules made up of repeated subunits. Proteins form these linear polymers by combining 20 different amino acids, each with unique chemical characteristics.

The sequences of these amino acids that make up the protein are stored in the DNA  located in the nucleus. The DNA is transcribed into RNA, and translated into proteins. The sequence of bases in RNA determines the order of successive amino acids that will result in new proteins. The formation of proteins occur within the ribosomes, which are large complexes of RNA and protein molecules. The sequence of amino acids in a protein is known as the primary structure that determine how the protein will fold. The interactions between those primary structures form local secondary structures, when the secondary structures interact they form the overall three-dimensional shape or its tertiary structure. These tertiary structures are called polypeptides, some proteins are a combination of these polypeptides forming quaternary structures.

These macromolecules play a vital role in immune defense, energy storage, and structure creation. They can also be used as enzymes to catalyze or speed up chemical reactions. Each enzyme recognizes one or more substrates to catabolize, synthesize, or rearrange their substrates. They can also send messages within cells and across the body. Examples include hormones such as insulin and glucagon that coordinate different body systems. Furthermore, they transport oxygen across the body through hemoglobin. Proteins allow for the wide range functions of life to maintain homeostasis and can become infinitely complex and add to life’s diversity.

Atoms can combine together to form molecules, and chemical bonds are the different forms of attraction between these atoms. The most common forms of chemical bonds are ionic, covalent, and hydrogen bonds. Each chemical bond has its unique attributes that make them strong or weak in a range of situations. Ionic bonds form between ions with opposite charges as electrons are transferred from one atom to another creating a strong bond. An example would a positively charged sodium ion attracted to a negatively charged chloride ion, making sodium chloride. Covalent bonds form between. Non-metal atoms when the electrons in outermost valence shells are shared. They form when hydrogen and chlorine ions combine to form hydrogen chlorideCovalent bonds can be polar or nonpolar. In polar covalent bonds, electrons are unequally shared by the involved atoms, causing slightly positive and slightly negative charges to form in different parts of the molecule. A polar covalent bond example would be the bonding of Hydrogen and oxygen between water molecules. Nonpolar covalent bonds form between two atoms of the same element or atoms that share electrons equally.

Finally, hydrogen bonds occur between a hydrogen atom with a slight positive charge and an electronegative atom of another molecule. Hydrogen bonds are much weaker than ionic or covalent bonds, but become much stronger as many hydrogen bonds form together. Hydrogen bonds give water its unique properties to support life, such as cohesion and adhesion. To summarize, chemical bonds Give atoms the ability to combine into more complicated and diverse structures that make up all known organic and inorganic molecules throughout the cosmos.

Taxonomy is the science of describing, naming, and classifying all living organisms. Taxonomists use genetics alongside behavioral and physical observations to classify all plants, animals, and microorganisms into specific classifications. Taxonomists have so far classified close to 2 million plants, animals, and microorganisms but an estimated 5 to 30 million different species exists on earth. As organisms become more loosely related they progress up an order until the 3 domains of life.  A species is the lowest level in taxonomy, they are classified as a group of organisms that have the capability to breed with one another.  As multiple species become loosely related they are classified as a genus. This trend progresses up a latter from species, genus, family, order, class, phylum, until the 3 domains of life.

The 3 domains of life are Eukaryota, Bacteria, and Archaea. Each domain has specific attributes with Eukaryotes composing life that most people see in their day to day activities. All animals, plants, fungi, and protists are in this domain, they have eukaryotic cells with membranes composed of unbranched fatty acid chains attached to glycerol by ester linkages and contain rRNA that is unique to this domain. Bacteria are prokaryotic cells that are similar to eukaryotes cells but contain no nucleus, lack membrane-bound organelles, and their own unique rRNA. Finally, the domain Archaea is composed of single-celled microorganisms more closely related to eukaryotes over bacteria. Archaean’s inhabit the extreme environments on earth such as deep sea rift vents and extremely alkaline or acid waters.

Shaina Song

What is a Macromolecule?

A macromolecule is a molecule that consists of large biological polymers, and the polymers are made up of smaller molecular subunits called monomers. Their functions are to store energy and/or be used for structure. There are four main classes of macromolecules which are lipids, carbohydrates, proteins, and nucleic acids.

Carbohydrates

Carbohydrates are one of the major macromolecules that are essential for the building blocks of life. They are often called “sugars” and are found in essential everyday needs such as fruits, vitamins, antioxidants, minerals, and more. Carbohydrates, also called saccharides, are molecular compounds made from three elements: carbon, hydrogen and oxygen.  They can function as a source of energy for the body, building blocks for polysaccharides and components of other molecules such as DNA, RNA and ATP. There are three main types of carbohydrates which are Monosaccharides, Disaccharides, and Polysaccharides.

Monosaccharides, known as simple sugars, are the simplest carbohydrates and are also the building blocks from much larger carbohydrates. These simple sugars have a molecular formula (CH2O)n, where n can be 3,5 or 6. The number of carbons within a monosaccharide are classified as trioses (n=3), pentoses (n=5), and hexoses (n=6). If the monosaccharide contains an aldehyde it is called an aldoses. However, if the monosaccharide contains a ketone then it is called a ketoses.

Disaccharides are products of two monosaccharides that’s been reacted. Most sugars are found to be disaccharides rather than monosaccharides. There are three types of disaccharides which are sucrose, lactose, and maltose which were all formed from a specific monosaccharide. Disaccharides tend to be soluble in water, but they are too large to enter through the cell membrane by diffusion.

Polysaccharides are made up of monosaccharides that have been chained together and each building block structure is called a monomer. The properties of a polysaccharide molecule depend on its length, additional side chain units, folding of the chain, and whether the chain is straight or coiled.

Nucleic Acids

Nucleic acids are one of the four major macromolecules that are essential for the building blocks of life. These molecules are called information molecules because they are large molecules that can carry information in the sequence of nucleotides that make them up. This molecular information in is much like the information carried by the letter in an alphabet, but in the case of nucleic acids, the information is in chemical form. The nucleic acid, DNA (deoxyribonucleic acid), is the genetic material in all organisms. It is transmitted from parents to offspring, and it contains the information needed to specify amino acid sequence of all the proteins synthesized in an organism. The nucleic acid, RNA (ribonucleic acid), has multiple functions; it is a key player in protein synthesis and the regulation of gene expression.

Works Cited

“Background on Carbohydrates and Sugars” International Food Information Council Foundation, n.d.Web. 26 Feb. 2017. < http://www.foodinsight.org/Background_on_Carbohydrates_Sugars>

“Carbohydrates” Royal Society of Chemistry, n.d.Web.26 Feb.2017 < http://www.rsc.org/Education/Teachers/Resources/cfb/carbohydrates.htm>

“Macromolecules” Olemiss University, n.d.Web. 26 Feb. 2017 < http://www.olemiss.edu/courses/bisc102/macromol.html>

“Nucleic Acids Encode Genetic Information in Their Nucleotide Sequence” Biology How Life Works,n.d.Web.26 Feb.2017 < https://reg.macmillanhighered.com/Account/Unauthenticated?>

Leeza-Marie Williams

Learning Summation

What is biology?

According to the Norwegian University of Science and Technology, the word biology is derived from the Greek words bios and logos which means life and study, respectively. Simply, biology can be defined as the science of life and living organisms. An organism is a living entity consisting of one cell like bacteria, or several cells such as animals, plants and fungi.

While the definition of biology appears straightforward, biological science can range from the study of molecular mechanisms in cells, to the classification and behavior of organisms, and to how species evolve and interact between ecosystems.

Furthermore, Biology often overlaps with other sciences, for example, biochemistry and toxicology with biology, chemistry, medicine, and even astronomy, to name a few. Biology also interacts with social sciences with regards to the administration of biological resources, developmental biology, biogeography, evolutionary psychology and ethics.

Properties of water

As stated by the website Owlcation, water consists of five properties which are as followed: an attraction to polar molecules, a high-specific heat, a high heat of vaporization, a lower density of ice, and a high polarity.

Firstly, waters ability to attract to polar molecules can be attributed to cohesion and adhesion. Cohesion refers to water’s attraction to other water molecules, whereby, the hydrogen bonds in water hold other water molecules together. Because of water’s cohesiveness, water in its liquid state has surface tension which allows for insects, such as Water Striders, to walk on water. Furthermore, water’s cohesiveness enables it to maintain its liquid state instead of a gas state at moderate temperatures. Adhesion is water’s attraction between molecules of a different substance in which it is able to form hydrogen bonds. Due to water’s adhesiveness, capillary action occurs.

Secondly, high-specific heat is the amount of energy that is absorbed or lost by one gram of a substance to change the temperature by 1 degree Celsius. Since water molecules form many hydrogen bonds between one another, plenty of energy is needed to break down those bonds. Breaking the bonds allows individual water molecules to move freely about and have a higher temperature. If there are many individual water molecules moving about, then, they will create more friction and more heat, which means a higher temperature. The hydrogen bonds between water molecules absorb the heat when they break and release heat when they form, which minimizes temperature changes. Water helps maintain a moderate temperature of organisms and environments.

Thirdly, water’s high heat of vaporization is the other property responsible for its ability to moderate temperature. It refers to the amount of heat energy needed to change a gram of liquid into gas. Just like the properties of having a high specific heat, water also needs an ample amount of energy in order to break down the hydrogen bonds which causes a cooling effect.

Fourthly, when observing water’s density at cooler temperatures, the hydrogen bonds of water molecules form ice crystals because they are more stable and will maintain its crystal-like shape. Ice is less dense than water because of the hydrogen bonds being spaced out and being relatively apart. The low density is what allows icebergs to float and is the reason why only the top part of lakes are frozen.

Fifthly, water is a polar molecule that has a high level of polarity and attraction to ions and other polar molecules. As we already know, water can form hydrogen bonds, which make it a powerful solvent. Water molecules are attracted to other molecules that contain a full charge, like an ion, a partial charge, or polar. Salt is a polar compound that dissolves in water. Water molecules surround the salt molecules and separate sodium from the chloride by forming hydration shells around those two individual ions.

Works Cited:

“What Is Biology at NTNU?” Norwegian University of Science and Technology, n.d. Web. 25 Feb. 2017.

<https://www.ntnu.edu/biology/about-us/what-is-biology>.

“5 Properties of Water.” Owlcation, 13 June 2016. Web. 25 Feb. 2017. <https://owlcation.com/stem/5-

Properties-of-Water>.