All cells contain the same basic building blocks – carbohydrates, lipids, proteins and nucleic acids – but most scientific discussions surrounding cell structure and function center around protein molecules.
Cells are dynamic. Even though cells under a microscope appear still, this may only be because they’ve been prepared for examination.
Proteins are one of the three macronutrients required for body growth and function, consisting of long chains of amino acids that form large complex molecules with many possible shapes in our bodies. There are 20 amino acids that can combine to make proteins, with each sequence determining its shape and purpose in our bodies.
Proteins perform an array of roles within cells and organisms, from catalyzing metabolic reactions to building cell structures like DNA and cell walls. Furthermore, proteins serve as hormones which regulate, conduct or control cellular processes.
Proteins are composed of polymer chains of amino acids connected by amide bonds (peptide bonds). Each amino acid can be identified by its R group functional group, which determines its exact chemical makeup; some have hydrocarbon R groups while others can be acidic or basic (glycine has just one hydrogen). Furthermore, its side chains may be either polar or nonpolar and either negatively or positively charged based on whether their R groups contain hydrogen atoms or not.
Carbs are one of three primary ways for the body to obtain energy (or calories). Carbs provide glucose as its principal fuel source and are utilized by cells for producing energy and function – including brain cells which are particularly sensitive to low blood sugar levels.
Carbs typically contain carbon, hydrogen and oxygen atoms and can form simple sugars such as glucose or more complex forms such as starches or fiber.
Carbs are essential to our bodies, serving both as energy sources and ingredients to produce fats and proteins. Proteins consist of amino acids strung together into complex structures; while some of these 20 amino acids can be synthesized by the body itself, nine of them must come from food: isoleucine, leucine, methionine, phenylalanine threonine tryptophan valine are known as essential amino acids. These essentials play key roles in digestion muscle building production of hormones/enzymes production as building blocks of life.
Lipids are nonpolar organic molecules that compose the mechanical barrier between cells and their environments known as membranes, providing energy to each. Lipids include fats and oils, waxes, sterols, glycerols, phosphatidylcholine glycolipids and more.
Most lipids are hydrophobic, meaning that they do not dissolve in water. Like proteins and carbohydrates, lipids contain carbon atoms which can bond together forming amphipathic structures with parts hydrophilic (water-loving) structures as well as some that are hydrophobic.
Fats and oils are among the most frequently consumed lipids by humans. Composed of three fatty acid chains linked by glycerol molecules, triacylglycerols (or triglycerides) provide stored energy as well as helping make up cell membranes which hold cells together, as well as being an important vehicle for transporting fat-soluble vitamins A, D and E.
Carbon atoms combined with other molecules compose most of the unique substances found in living things, including proteins, carbohydrates, lipids and nucleic acids.
Nucleic acids form the genetic basis for all free-living organisms and many viruses. They play an essential role in protein synthesis and determine our inheritable characteristics; there are two natural forms: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
DNA is stored in the nuclei of eukaryotic cells while RNA serves as genetic material in prokaryotic cells and certain viruses. Both contain deoxyribose or ribose with an attached phosphate group, along with four different nitrogenous organic bases –adenine (A), guanine (G), cytosine (C) and thymine (T) or uracil (U), that compose nucleotide subunits to create nucleotides.
DNA encodes information, while RNA acts as its working form to translate this sequence into amino acids in cells to make proteins.