Bacteria Are Everywhere as Bad as Good

Bacteria is everywhere, but it’s so small that the human eye can’t see it. Bacteria are anywhere from your phone to your intestine. Bacteria can even be found or used in certain foods “People have long used bacteria to convert milk to cheeses and yogurt”( Urry Lisa A. p.492). Since bacteria are so small, we don’t draw much attention to it, some might even forget to wash their hands from time to time, “There are 2 to 10 millions of bacteria on your fingerprints… the number doubles… after you use the toilet”(Gross! Hand Hygiene and Other Germy Facts). Most people don’t know what bacteria looks like or what bacteria is. The purpose of this lab was to learn and obtain a better understanding of how the structure of bacteria plays a key role in their survival. As well as getting hands-on experience, we practiced some of the most common techniques, when dealing with cultures of bacteria. We also learned how to properly use stain, to distinguish the bacteria and their structure.

Another purpose, of why we did this lab was to draw some correlations, between gram-positive gram-negative bacteria and whether it makes them more prone to creating a resistance to antibiotics. We also wanted to see how being gram-positive/negative affects the growth of bacteria. We also learned some key characteristics that set bacteria apart from each other, and help them function more efficiently. This lab gave us a more in-depth picture of bacteria in our environment, as well as the relationships we have with them. Bacteria play a key role in our everyday lives, but as well as in our ecosystem. Even the smallest species like bacteria make an extreme difference in our health and our plant, that is why it was important for us to have an understanding of the structure as well as their growth, which makes them more prone to mutations and survival.

Personally, before this lab, I didn’t have much knowledge, let alone an understanding of bacteria. I thought that the bacteria’s structure was all the same. I believed that poor hygiene led to bacteria. I know that this is only partly true, this only makes it easier for bacteria to spread, but it doesn’t cause bacteria itself. I also believed that all bacteria were bad, and could potentially harm, and even kill us, if not treated. I even thought that it was very easy, to kill the bacteria, but in reality, it’s hard. After this lab, I realized that I had various misconceptions about bacteria.

Prokaryotes are one of the earliest forms of life and are over 3.5 billion years old. For two billion years, prokaryotes were the only living things on our planet. The vast diversity between prokaryotes has resulted, in a long course of their evolution. Prokaryotes make up two domains bacteria and archaea. “Early Earth was prone to geological upheaval and volcanic eruption and was subject to bombardment by mutagenic radiation from the sun.

The first organisms were prokaryotes that could withstand these harsh conditions.”(22.1B: The Origins of Archaea and Bacteria). In the 1950’s Stanley Miller, demonstrated the probable spontaneous synthesis of organic molecules, by stimulating early earth’s atmosphere, in his lab. In earth’s primitive, simple organic molecules, could form and spontaneously polymerize into a macromolecule. The atmosphere contained little to no oxygen, it mostly contained carbon dioxide and Nitrogen. Earth’s early atmosphere consisted of Methane, Ammonia, and hydrogen, other gasses in the atmosphere, which resulted in electric sparks to be released. This created a numerous variety of organic molecules, including various amino acids. The heating of amino acids resulted in polymerization to form (polypeptides) macromolecules. “But the critical characteristic of the macromolecule from which life evolved must have been the ability to replicate itself”(Cooper, Geoffrey M.).

Only a macromolecule capable of directing the synthesis of new copies of itself would have been capable of reproduction and further evolution. Nucleic acids and proteins are two very informational macromolecules, in today’s research. A nucleic acid is the only macromolecule, capable of managing their own self- replication. “Nucleic acids can serve as templates for their own synthesis as a result of specific base pairing between complementary nucleotides” (Cooper, Geoffrey M.). Sid Altman and Tom Cech discovered that RNA can catalyze numerous chemical reactions, including the polymerization of nucleotides. Scientists believe that there was an evolution period in time known as the RNA world. RNA is believed to have been the initial genetic system, and chemical evolution, based on self-replicating RNA, that now forms what we know as DNA.The first cell is assumed to have emerged by the circumscribed of self-replicating RNA in a membrane composed of phospholipids.

Phospholipids are amphipathic molecules, they have hydrophobic tails, and hydrophilic heads, that contain a phosphate, when a phospholipid is placed in water, it creates a bilayer. The phospholipid forms a very stable barrier between two liquid compartments. The evolution of the cell’s metabolism, was essential, for present-day prokaryotes. Cells, were capable of obtaining energy and food, in the earth’s primitive environment. But this was self-limiting, so they evolved their mechanisms for generating energy. Today some organisms obtain energy from the light (phototrophs), from chemicals (chemotrophs), who use CO2 as energy (autotrophs), and heterotrophs, who need one organic nutrient. Now prokaryotes have certain structures and characteristics that make them able to survive. “Prokaryotic cells(bacteria) lack a nuclear envelope”(Cooper, Geoffrey M.). Since prokaryotic cells, don’t have a nucleus, the “DNA is found in the central part of the cell called the nucleoid”(4.2A: Characteristics of Prokaryotic Cells). They also lack membrane-bound organelles.

They tend to have a plasmid, which is where they only carry a few genes. Prokaryotes have a cell wall, that is made up of peptidoglycans, which act as a protection layer. It also maintains the shape of the cell and prevents dehydration. Prokaryotic cells are far less complex than eukaryotes they are also generally smaller in size. “They do not contain cytoplasmic organelles or cytoplasmic skeleton.”(Cooper, Geoffrey M.). Most bacterial cells are spherical, spiral, or rod-shaped. The rod shape helps them swim better, spherical-shaped bacteria face more frictional resistance. Scientists believe the difference in shape is to create selective advantages whenever there is a completion of nutrients. Most of the cell walls have a capsule: a sticky layer of polysaccharides or proteins, that surrounds the wall. It helps protect against dehydration, while others shield pathogenic attacks from host immune systems. Other cells developed resistant cells: endoscopes, due to lack of nutrients. Endoscopes can withstand harsh conditions.

Most prokaryotes have fimbriae they hair-like follicles that surround the whole cell. This helps them stick to other prokaryotes or substrates. They also have flagella that help them move. They have Pilis that is used when recombination of genes occurs. A. A prokaryote is either F+ or F-, the F stands for fertility, if it is F+ then it donates it bacteria to other cells if it is F- then its the recipient of the host genes but after this, it will be F+. This is why bacteria are diverse and have revolutionized tremendously over the course are time. There are pathogenic bacteria that release endotoxins, that cause disease. Prokaryotes are unique and are a key role in our lives, “All life would perish from our planet if prokaryotic organisms were to disappear”(Prokaryotic Cells). We study bacteria because they are used to study genes and enzymes.one of the benefits of bacteria is that they can break down organic compounds. This is useful for activities such as waste processing and toxic waste. Another benefit is that they are sometimes used as alternative pesticides.