Macromolecule
Macromolecules are large and essential molecules vital for the proper functioning of the human body. There are four primary types of macromolecules: carbohydrates, proteins, lipids, and nucleic acids, each serving distinct and crucial roles. Carbohydrates act as a primary energy source, with simple sugars like glucose found in foods such as bread and pasta, while complex carbohydrates like starch and glycogen serve as energy storage. Proteins, composed of amino acids, are fundamental for numerous biological processes, including enzyme activity, hormone regulation, and cellular signaling.
Lipids, which include fats, steroid hormones, and phospholipids, are important for energy storage and cell membrane structure. Fats can be saturated or unsaturated and play roles in energy storage and heart health, while phospholipids are crucial for maintaining cell membrane integrity. Lastly, nucleic acids, including DNA and RNA, are key to genetic information storage and protein synthesis, with DNA encoding an organism's traits and RNA facilitating protein production. Understanding these macromolecules is essential to grasp how the body functions and maintains life.
Macromolecule
Macromolecules are large molecules that are essential for the proper functioning of the human body. The four types are carbohydrates, proteins, lipids, and nucleic acids. These each play a different role in the human body, and without these molecules, humans would not be able to survive.
Carbohydrates
Carbohydrates are a source of energy for the body. They can be found in both plant and animal foods. For example, the carbohydrate glucose, a monosaccharide, or simple sugar, is found in starchy foods such as potatoes, bread, and pasta. Starch is used by plants for the storage of glucose.
Animals use a polysaccharide, a complex sugar called glycogen, to store energy. Glycogen can typically be found in the muscles and liver of the body. The carbohydrate cellulose makes cell walls. When people ingest cellulose, it is then called fiber. In mushrooms and certain animals' exoskeletons, a carbohydrate called chitin exists. Chitin is made from bonded glucose molecules. Ingested in small amounts, carbohydrates have a wide range of health benefits for the human body and help it to operate smoothly. Ingested in excess, carbohydrates can be harmful to health.
Proteins
Proteins have complex functionality as macromolecules. Made from chains of amino acids, which are the building blocks of proteins, proteins have a range of functions. They can receive chemical signals as receptors, break down foods as enzymes, exercise control over bodily function as hormones, or facilitate the movement of molecules through a membrane.
The structure of a protein's molecules is determined by the sequence of its amino acids. Twenty amino acids exist, half of which are manufactured by the body and the other half of which are obtained from food. The order in which amino acids are arranged differentiates one protein from another. The secondary structure is a general shape the macromolecule takes. It may either fold like a pleat or form into a twisted spiral, also known as a helix. When macromolecules bond, they may form another shape, such as circular or elongated.
Lipids
Three primary types of lipids exist: fats, steroid hormones, and phospholipids.
Fats
Fats are made up of saturated or unsaturated fatty acids. Saturated fatty acids do not have double bonds within the fatty acid chain, and unsaturated fatty acids have at least one double bond.
When fats are at room temperature, they are usually solid or semisolid. Butter and margarine are examples of fats that contain saturated fatty acids. Liquids such as cooking oils are examples of unsaturated fatty acids. Consumed in small amounts, fats are not harmful; however, when eaten in excess, they do not break down in the body as they should. They collect in the blood vessels and can cause heart disease by blocking the flow of blood throughout the body. When present in the bodies of animals or the cells of plants, fats store energy obtained from the consumption of food.
Steroid Hormones
Steroid hormones are produced by the body naturally and play a variety of role in the body's activities. They have several functions. Cholesterol, for example, keeps the membranes surrounding cells limber, which means they are less prone to damage. Cortisone may be given to patients suffering from allergies; estrogen aids in the development of secondary sexual characteristics in women; and androgen helps men develop secondary sexual characteristics. Glucocorticoid helps people to cope with physical or psychological stress, and progesterone ensures that women are able to maintain a successful pregnancy.
Phospholipids
Phospholipids, the third kind of lipid, have a different molecular structure. They have a round head with two spindly tails. The head is made of glycerol and can bond with water, while the tail is made of fatty acids and cannot bond with water. The primary purpose of the phospholipid is to provide flexible and strong materials for cell membranes and other membranes in the human body. Phospholipids ensure that cell membranes are semipermeable, meaning that water can flow through the membrane but stay contained within the cell.
Nucleic Acids
Nucleic acids are complex but important to the body. Deoxyribonucleic acid (DNA), the material that determines the unique characteristics of an organism, is an example of a nucleic acid. Ribonucleic acid (RNA), a substance found in the cells of plants and animals that helps make proteins, is another example. DNA can be found in the nucleus of human cells and in the cytosol (material that fills a cell) of bacteria cells. This means that DNA can be obtained from any part of the human body.
The DNA molecular structure is double-stranded, twisted into a shape known as a double helix, while RNA has a single strand. In addition to determining appearance and behavior traits, the information stored in a DNA molecule aids in the manufacture of protein. RNA's sole function is to aid in the manufacture and processing of proteins. DNA is the same molecular structure that assigns traits, such as hair color, eye color, or height, and is passed down through generations. Paternity and other blood ties can be identified through DNA testing. However, not all members of a family will have the same traits; genes mutate with the beginning of each new generation.
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