Ecosystems and Population Dynamics: Key Concepts
Ecosystems: Definition and Types
An ecosystem is a system composed of a set of interrelated elements. Specifically, it consists of a biotope and a biocenosis, which produce many complex interactions between its components.
- Biotope: A substrate comprising physical and chemical characteristics.
- Biocenosis: All living organisms within the ecosystem.
Types of Ecosystems
- Terrestrial Ecosystems: These are conditioned by climate. Ecological factors are dependent on weather conditions. There is a great diversity
Enzyme Function and Regulation: Key Concepts in Biochemistry
Enzyme
A biomolecule that catalyzes chemical reactions.
Absolute Specificity
The characteristic of an enzyme that it acts on one and only one substance.
Relative Specificity
The characteristic of an enzyme that it acts on several structurally related substances.
Stereochemical Specificity
The characteristic of an enzyme that it is able to distinguish between stereoisomers.
Substrate
The substance that undergoes a chemical change catalyzed by an enzyme.
Inborn Error of Metabolism
A disease in which a genetic
Read MoreOrgan Transplants, Human Reproduction, and Genetic Engineering
Types of Transplants
- Autograft: Donor and recipient are the same individual.
- Isotransplant: Donor and recipient are identical twins.
- Xenotransplantation: Donor and recipient are different species.
- Allogeneic: Donor and recipient are of the same species but are not genetically identical.
Problems of Transplants
- Immune Rejection: White blood cells detect something odd and try to destroy it. So, if the donor and recipient are not identical, rejection will occur. To avoid rejection, powerful drugs called
Muscle Contraction and Respiratory System Anatomy
Muscle Contraction Process
5. Calcium ions released from the sarcoplasmic reticulum are available next to the actin and myosin.
6. The calcium ions bind to troponin molecules, modifying their structure. This change allows the myosin filaments to join them, forming cross-bridges linking the actin and myosin.
7. Segments of myosin adopt a rounded head shape extending from the body of the myosin filament. This head can degrade ATP in the presence of calcium and use its energy in the process of contraction.
Read MoreRenal Pathology: Diseases, Symptoms, and Treatment
Renal Pathology
Filtration is a process that allows the passage of fluid from the glomerulus to Bowman’s capsule by the blood pressure difference between the two areas.
Tubular reabsorption is responsible for recovering useful substances returned to the circulation, allowing toxins to continue their journey through the kidney.
Tubular secretion maintains the normal acid-base balance: reabsorption of filtered bicarbonate and excretion of protons.
Disease Etiology
Infection, immune, or intraglomerular
Read MoreNeurons, Synapses, and the Nervous System
T.2.1 Neurons: Electrical Properties
Neurons are the cells of the nervous system. They are connected and are responsible for transmitting information from sensory systems to the nervous system (brain and spinal cord). They prepare responses sent to the effector organs (muscles and glands).
Structure of Neurons: They consist of a cell body, neuronal endings called dendrites, and a longer extension called an axon. The axons of neurons can associate with attached cells called Schwann cells with a lipid
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