Cell Cycle Phases and Cellular Division: Mitosis vs. Meiosis
The Cell Cycle
Interphase: This is the initial, long stage where cell division does not occur. It is characterized by cell growth and the development of normal metabolic activities.
- G1 Phase: Follows the previous cell’s mitotic cycle and is a stage of cell development. At the end of the G1 phase, there is a point of no return (the restriction point or R point), after which the entire process cannot be stopped. Phases S, G2, and M will inevitably follow. Some cells, before reaching the R point, undergo
Cell Structure and Function: Prokaryotic and Eukaryotic Cells
Cell Structure and Function
The cell is the structural unit of living beings. The cell is the functional unit of living beings; it carries out all the metabolic processes that allow it to live. Every cell comes from another pre-existing cell. The cell is the genetic unit of all living beings.
Levels of Organization
The subject has different organization levels, each more complex structurally and functionally than the previous one: subatomic particles, atoms, molecules, macromolecules and supramolecular
Read MoreOrigin and Evolution of Life: From Early Theories to Natural Selection
The Origin of Life: Early Explanations
Early explanations for the origin of life are deeply rooted in the realm of gods, mythology, and the supernatural. The life and death of loved ones were often attributed to these forces, as were any natural phenomena.
Early Theories
Aristotle developed the idea of spontaneous generation, according to which life arises without divine mediation from the combination of the four elements: fire, air, water, and earth. He described the birth of fish, mice, and insects
Read MoreUnderstanding Stroke: Types, Causes, and Symptoms
Stroke: Neurological Deficits
A stroke, also known as a cerebrovascular accident (CVA), is characterized by neurological deficits. Except for subarachnoid hemorrhage (SAH), it typically presents with focal symptoms that develop over hours or days. It is not a seizure and lasts for more than 24 hours. It is caused by vascular disease.
Transient Ischemic Attack (TIA)
A transient ischemic attack (TIA) is a clinical syndrome characterized by an acute loss of brain function or monocular vision that lasts
Read MoreCellular Respiration: Electron Transport Chain and Fermentation
The Respiratory Chain: Concept and Objectives
Definition
The respiratory chain consists of the transport of electrons from reduced coenzymes, NADH + H+ and FADH2, to oxygen. This transport takes place in the membrane of mitochondrial cristae.
Objectives
- In this process, most of the energy contained in glucose and other organic compounds is obtained and stored as ATP.
- Simultaneously, the electron carrier coenzymes are recovered in their oxidized form, which allows for further chemical oxidation of glucose
Cellular Respiration and the Human Respiratory System
The cell uses a portion of the nutrients for manufacturing its own materials. Cellular respiration takes place in the mitochondria. During respiration, a phenomenon of glucose occurs.
Key aspects of cellular respiration:
- Consumption of oxygen occurs during the oxidation of nutrients.
- Liberation of energy allows the cell to perform its functions.
- Production of carbon dioxide and water.
The Respiratory System
The respiratory system is responsible for the exchange of O2 and CO2 gases between the organism
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