Cellular Respiration and Fermentation Processes
Cellular Respiration
Cellular respiration is the process where glucose is completely oxidized to CO2 and H2O with O2 intervention. This catabolic pathway occurs in the mitochondria of eukaryotes or in the cytoplasm and plasma membrane of prokaryotes.
The pyruvate obtained in glycolysis is broken down in three stages:
1. Oxidative Decarboxylation of Pyruvate
Pyruvate from glycolysis enters the mitochondrial matrix and undergoes decarboxylation, releasing a CO2 molecule, while NAD+ is reduced to NADH.
Read MoreUnderstanding Species Evolution
What is a Species?
A species is defined as a group of organisms capable of interbreeding and producing fertile offspring.
How Does Evolution Occur?
Natural Selection
Charles Darwin proposed natural selection, or “survival of the fittest,” as the driving force behind evolution. For example, in a lion pride, the strongest cubs are more likely to survive and reproduce, passing on their advantageous traits. Over generations, these accumulated changes can lead to the emergence of a new species.
Jean-Baptiste
Read MoreMediastinum Anatomy and Fetal Circulation
Mediastinum
- Occupied by the tissue mass between the two lung cavities. Covered by the mediastinal parietal pleura on each side and contains all thoracic viscera and structures except the lungs.
- Extends from the upper chest opening to the diaphragm inferiorly, and from the sternum and costal cartilages anteriorly to the thoracic vertebral bodies posteriorly.
- High mobility due to mostly hollow visceral structures held by loose connective tissue, often infiltrated with fat.
Superior Mediastinum (Manubrium
Read MoreHuman Biology: Digestion, Respiration, Circulation, and Excretion
Digestive Function
Ingestion: Intake of food into the digestive tract through the mouth. Food is crushed by the teeth, mixed with saliva, and begins digestion.
Digestion: Processing of food into nutrients that can be utilized by cells. This occurs through two types of actions:
- Mechanical: Physically breaking down food through cutting, grinding, and churning. This occurs in the mouth and stomach.
- Chemical: Transforming food into simpler compounds using substances that cause chemical changes. This starts
Ecosystem Dynamics: Exploring Biological Interactions and Environmental Factors
Ecosystem Dynamics
Species and Populations
Two individuals belong to the same species if they can reproduce and produce fertile offspring. A population consists of individuals of the same species living in a particular area.
Biocenosis and Biotope
A biocenosis is a group of populations sharing a territory and interacting with each other. The territory occupied by a biocenosis is called a biotope. A biotope combined with a biocenosis forms an ecosystem.
Ecology and the Ecosphere
Ecology is the science
Read MoreUnderstanding DNA and RNA: From Nucleotides to Double Helix
Nucleic Acids: Polymers of Nucleotides
Nucleic acids, DNA and RNA, are polymers formed by the union of nucleotide subunits.
Composition
Nucleic acids are composed of:
- A nitrogenous base
- A pentose (sugar)
- Phosphoric acid (phosphate)
Nitrogenous Bases
These are nitrogen-containing heterocyclic compounds. There are two types:
Purine Bases
Purine derivatives with a double ring structure. The most important are adenine (A) and guanine (G), found in both DNA and RNA.
Pyrimidine Bases
Pyrimidine derivatives with a
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