Proteins (macromolecules) are essential for life. They perform countless processes including cell signaling and even muscle contraction. The molecule itself, however, does not carry the information for these functions; it’s the arrangement of its structure. Therefore, how a protein will form is dictated in its coded instructions, known as DNA.
Cell Membrane
The cell membrane is not actually a part of the cell, but rather a part of the cell wall. It functions as a barrier to protect the cell’s contents and structure and also serves as a channel for exchanging materials between the inside of the cell and its environment.
The main component of the cell membrane is called phospholipid, which makes up about 50 percent of the membrane’s weight. The phospholipid molecule has two parts: a head that is hydrophilic (water-attracting) and two tails that are hydrophobic (water-repelling). These molecules are naturally arranged in two layers, with their heads facing outwards on both sides and their long tails facing each other inwards.
This arrangement creates what’s known as a bilayer, which allows for selective permeability. The bilayer can easily allow water to pass through because it’s made up of molecules that are attracted to water, but molecules like proteins need something called a transport protein to pass through it—these transport proteins act as channels that allow them to move across the membrane more easily.
Nucleus
The nucleus is the control center of a cell. It contains the genetic material in the form of chromosomes. The nucleus controls all of the cell’s metabolic activities, including cell division and growth, the manufacture of proteins and other products, and cell reproduction.
The nucleus is located in the center (nucleus means “center”) of a eukaryotic cell. The nucleus is surrounded by a nuclear membrane, which separates it from the rest of the cell. The nuclear membrane has pores (tiny openings) that permit certain substances to travel in and out of the nucleus.
Inside the nucleus are tightly packaged chromosomes, which contain nucleic acids, such as deoxyribonucleic acid (DNA), and proteins. DNA contains coded instructions that direct all of a cell’s activities. Proteins carry out these instructions by regulating the synthesis (production) of other proteins.
In most cells, there is more than one nucleus; these are known as nuclei.
Mitochondria
The mitochondria is an organelle that generates energy for the cell. Maybe you’ve heard it called the powerhouse of the cell, and for good reason—mitochondria are responsible for creating adenosine triphosphate (ATP), a molecule serving as the main source of energy for all living things.
ATP forms in the mitochondrial matrix, the space inside the mitochondria where two other processes take place that are vital to cell function: Lipid synthesis, or the creation of lipids to help transport nutrients through body tissues; and protein synthesis, which occurs when ribosomes create proteins based on coded instructions from DNA.
Vacuole
Vacuoles are large, fluid-filled spaces that serve a number of different functions in the cell. They can store food, aid in digestion, and act as waste receptacles inside the cell. Most plants have a central vacuole that takes up most of the space inside the cell.
In some plant cells, the vacuole may take up more than 90 percent of the available space! Vacuoles also play an important role in helping to maintain the shape of plant cells.
The rigid cell wall is strong enough to hold up the cell and keep its shape without any support; however, when a large vacuole is filled with water and stretches out toward the cell wall, it provides extra support. This helps to prevent the collapse of plant cells when they are under pressure from other nearby cells or external forces.
Ribosome
You may have heard the term “ribosome” before, but you might not be quite sure what it is. Well, the ribosome is a structure that makes proteins using coded instructions.
You can find ribosomes in both prokaryotic and eukaryotic cells as they carry out protein synthesis. As we mentioned, ribosomes are made of proteins and RNA molecules that come together to form a structure that looks like two subunits.
The larger subunit is where the protein synthesis occurs and the smaller subunit is where the transfer RNA (tRNA) enters. The tRNA contains an amino acid that is added to the growing polypeptide chain in protein synthesis. This important process occurs when messenger RNA (mRNA) binds to a ribosome and transfers genetic code from DNA to mRNA in a process called transcription.
Then, during translation, the mRNA moves through the larger subunit of the ribosome to specify which amino acids should be used to make a specific protein. The information on how a specific protein should be made comes from codons, which are three-nucleotide sequences on mRNA. These nucleotides bind with complementary anticodons on tRNA molecules with attached amino acids to form each strand of a poly
Last Words
Cells receive information from other cells, such as, “make more hemoglobin,” by way of a Molecular Messenger called a “RNA strand” (ribonucleic Acid). In this case, the RNA strand is the Code for making more Hemoglobin. These Messenger RNAs carry coded instructions from one cell to another. Scientists can write in the instructions using Genetic Information and then send them where ever they want with a Virus that specializes in transporting it between cells.