Cellular Structures and Genetic Processes: An In-Depth Look
Nucleus
The nucleus contains genetic information. It can be single or multiple, round, cubic, or poly-lobed. It’s located either centrally or laterally within the cell. We distinguish between the interphase nucleus and the nucleus undergoing mitosis.
Parts:
- Nuclear membrane: Double membrane (external and internal).
- Nuclear pores: Formed by the nuclear pore complex, an octagon of 8 subunits of nuclear pore proteins with a central granule. It allows the exchange of molecules in both directions.
- Matrix:
Human Nutrition: Essential Nutrients and Balanced Diet
Food and Nutrition
Nutrition describes the set of processes by which an organism obtains energy and matter necessary to develop its own structures and perform vital functions. Nutrition is an involuntary process that involves various organs and systems. Food makes up our diet and is necessary for our nutrition. Food is a conscious and voluntary act.
Types of Nutrients
- Inorganic nutrients: These can come from animal and plant sources, and also from non-organic sources. Examples include water and mineral
Cellular Processes and Body Systems
Mitosis
Mitosis is the process of forming two daughter nuclei through a single division. The resulting cells, or daughter nuclei, are identical. Daughter nuclei are diploid (2n). Mitosis occurs in somatic cells for growth and repair processes. There is no pairing of homologous chromosomes.
Endocrine System
The endocrine system is the set of organs and tissues that release hormones. Endocrine organs are also called ductless glands or endocrine glands because their secretions are released directly
Read MoreUnderstanding the Human Circulatory System and Blood Groups
The Circulatory System
The circulatory system is responsible for transporting substances throughout the body. It consists of a pump (the heart), a liquid (blood), and a series of vessels (blood vessels) through which blood is pumped. The blood reaches all parts of the body, collecting tissue debris and carbon dioxide, and delivering oxygen and nutrients needed by cells.
Composition of Blood
Blood consists of a liquid called plasma and different types of blood cells. Blood plasma is a thick, yellowish
Read MoreEndocrine System: Adrenals, Pancreas, and More
The Endocrine System: A Closer Look
Adrenal Glands
The adrenal glands are two small glands located in the abdomen, on either side of the vertebral column, atop the kidneys. They secrete adrenaline and noradrenaline, which act in stressful situations, promoting alertness and wakefulness. They also secrete corticosteroids:
- Glucocorticoids: Involved in the metabolism of carbohydrates, proteins, and fats, and block inflammatory responses to allergic reactions.
- Androgens (testosterone): Have a masculinizing
Microbiology Concepts: Taxis, Endobiosis, Symbiosis, and Gram Staining
Key Concepts in Microbiology
Taxis
Taxis is the directed movement of a bacterium in response to a concentration gradient, either physical or chemical, allowing it to position itself where it can better perform its vital functions. There are two types:
- Attractants (+): Substances that cause bacteria to move towards them, usually nutrients.
- Repellents (-): Substances that cause bacteria to move away, typically toxic.
Bacteria have receptors on their surface capable of distinguishing between harmful substances
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