Single-celled organisms. They possess a cell wall and plasma membrane but lack a true nucleus. DNA is scattered throughout the cytoplasm, and they contain ribosomes.
Have a true nucleus and organelles dispersed in the cytoplasm. They can be unicellular or multicellular.
Carbohydrates: compounds composed of carbon, hydrogen and oxygen, comprising sugars and derived substances.
Monosaccharides and soluble disaccharides: sweet-tasting, soluble in water, crystalline solids, etc.
Lipids: compounds of C, H and O, also P, K and S. Common characteristics: oily, insoluble in water, soluble in organic solvents.
Saponifiable: lipids that originate esters that can be hydrolyzed. They are classified as:
Molecules manufactured by B lymphocytes in response to contact with an antigen. Chemically, they are globular plasma proteins that detect and specifically bind to the antigen, leading to the humoral immune response. This allows them to detect and neutralize or bind to microorganisms that are then phagocytosed by macrophages.
A molecule capable of triggering an immune response. These molecules are foreign; the immune system does not recognize them as its own. They are detected by antibodies. Antigens are macromolecules of protein or polysaccharide nature.
This occurs when the immune system synthesizes antibodies against the organism itself. It is an...
Immunology studies the processes involved in recognition and rejection of foreign substances or potentially harmful organisms. The immune system is the complex set of defense mechanisms that allow living things to protect themselves.
Antigen: a molecule, often located outside a cell or organism, which is recognized as foreign and that induces an immune response.
The immune system comprises leukocytes and antibodies.
Health initiatives are often geared toward reducing exposure to various factors that are carcinogens, such as alcohol, tobacco, and diet. Recent years have spawned a new area of scientific knowledge: epigenetics, which studies the influence of the environment on gene expression.
Some diseases of the nervous system are due to malfunctioning neurons or injuries provoked by varied causes, such as high blood pressure, strokes, or lack of blood supply. The most important mental health challenges include:
Characterized by deep sadness and an incapacity to lead a normal life.
A disease that can present from adolescence, provoking serious personality disorders and disconnecting
DNA is a large molecule formed by the union of simpler molecules called nucleotides. They are composed of phosphoric acid, deoxyribose, and a nitrogenous base (adenine (A), guanine (G), cytosine (C), or thymine (T)).
DNA consists of two long chains of nucleotides twisted into a double helix. Adenine joins with Thymine (with double hydrogen bonds), and Guanine joins with Cytosine (with triple hydrogen bonds).
Cellular enzymes are used to cut and join fragments of DNA within cells. Restriction enzymes are responsible for "cutting" the DNA, and ligases unite the fragments.
Cloning a DNA fragment consists of obtaining billions of identical copies of that...
The morphology of the virion capsid is defined by its composition of multiple copies of a single protein or several different proteins, each encoded by a viral gene. A capsid, along with the nucleic acid it contains, is called a nucleocapsid. Virions exhibit two primary types of symmetry: helical and icosahedral.
This is a helical protein structure with RNA or DNA protected inside it.
An icosahedral virus is a polyhedron composed of 20 identical, equilateral triangular faces.
In some viruses, the nucleocapsid is coated by an outer shell, or envelope, which is a fragment of the host cell's plasma membrane acquired as the virus emerges through a process called budding.
Some...
The schema describes the basic functional relationships between DNA, RNA, and proteins. In essence, DNA provides a model for its own replication and transcription. RNA is translated into proteins, formed under the encoding determined by its nucleotide triplets.
The two strands are separated, and from each, according to the rules of base complementarity, the respective complementary strands will be constructed.
Bacteria are grown with N15 (heavy nitrogen) and separated by centrifugation in a medium with a density gradient.
The term Eukaryote comes from the Latin eu (good or true) and karyon (nucleus).
Protein Structure
Primary Structure: The primary structure is the sequence of amino acids joined by peptide bonds. These radicals are arranged alternately on either side.
Secondary Structure:
-Alpha-helix Structure: This is a structural complication of the primary structure, resembling a helix. The links that rotate the structure are non-peptidic. It was formed in two phases:
1. There is a shift from one plane to another, similar to a door opening, approximately 100 degrees.
2. There is a 180-degree rotation around an axis located in the central part of the plane. This movement leaves the plane in an inverted position, higher than the anterior plane.
These two movements are simultaneous, and their repetition forms a double alpha-helix. All oxygen...