Cellular Processes: Photosynthesis, Respiration, Transport

Photosynthesis and Cellular Respiration

Photosynthesis is a process used by plants, algae, and some bacteria that harnesses energy from sunlight. Cellular respiration is a process that takes place in all parts of the body of living beings, in all their cells. Through respiration, living beings obtain the energy required for their development and daily activities by decomposing organic substances in the presence of oxygen.

Cellular Transport

  • Active transport: Occurs within the cell with energy expenditure.
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Population Ecology: Key Concepts and Interactions

Ecology: Key Concepts and Interactions

Ecology

The study of the distribution and abundance of organisms and the flows of energy and materials between abiotic and biotic components of the ecosystem.

Demography

The study of rates of births and deaths, age and sex structure, and distribution.

Population

A group of potentially interbreeding individuals inhabiting a specific area.

Density

The number of individuals per unit area.

Ecological Density

The number of individuals per unit area of suitable habitat.

Crude

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Health, Disease, and the Human Body

Health

Health is a state of well-being and optimal social functioning, encompassing both physical and mental aspects. Determinants of health include:

  • Lifestyle and health behaviors: Avoiding tobacco, alcohol, and drugs; maintaining good nutrition; and engaging in regular physical exercise.
  • Environment: Social, physical, and psychological factors.
  • Biology: Aging, constitution, and inheritance.
  • Systems of healthcare: Prevention, rehabilitation, and healing.
  • Social acceptance: Being accepted or not accepted.
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Protein Synthesis: Elongation, Termination, and Regulation

Protein Synthesis Stages

22) Translation Elongation: The nascent polypeptide chain is extended by the covalent bonding of successive amino acid units. Each amino acid is carried to the ribosome by its tRNA, which is positioned correctly to match the corresponding codon in mRNA. Elongation requires cytosolic proteins called elongation factors, and the binding is powered by the hydrolysis of GTP.

23) Termination and Release: Polypeptide chain termination is signaled by a stop codon in the mRNA. The

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Human Digestive System: Processes and Functions

Human Digestive System: Processes and Functions

  • The human digestive system is composed of:
    • A digestive tract that extends from the mouth to the anus, through which food passes.
    • A set of glands that pour their secretions into the digestive tract. These include salivary glands, the pancreas, the liver, and gastric glands.

Structure of the Digestive Tract

It consists of four layers:

  • Mucosa: The inner layer, formed by lining epithelium. It contains cells that secrete mucus, which lubricates and protects the
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Histology of Human Tissues: Ureter, Bladder, Urethra, Spleen, Tonsils, and Skin

Ureter

Mucosa: Transitional epithelium and fibroelastic lamina propria. Smooth muscle: Two or three layers (longitudinal and circular, internal and external), with an outer longitudinal layer in the lower third. Adventitia.

Bladder

Transitional epithelium: Laminated epithelium consisting of cubic basal cells, polygonal intermediate cells, and superficial umbrella cells. Fibroelastic lamina propria. Smooth muscle. Adventitia.

Urethra

Mucosa, muscle, adventitia.

  • Male (20-25 cm): Transitional epithelium
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