Notes, summaries, assignments, exams, and problems for Biology

Carnitine: An Essential Nutrient

Carnitine is a nutrient synthesized in the liver, kidneys, and brain from two essential amino acids: lysine and methionine. Carnitine is responsible for transporting fatty acids into the mitochondria, cellular organelles responsible for energy production.

Some individuals need carnitine supplements to maintain normal metabolism, which indicates that carnitine should be considered an essential nutrient.

Carnitine Deficiency

Carnitine deficiency is classified into two major groups: systemic deficiency (rare) and myopathic (more common). The systemic form affects the whole body, while the myopathic form affects only muscle tissue.

Causes of Carnitine Deficiency

Known causes of carnitine deficiency include:

• Deficiency

Population, Community, and Ecosystem

A population is a group of individuals of the same species living in a specific area. A community is a set of populations inhabiting the same area. The biotope is the physical environment occupied by a community, characterized by specific environmental conditions. An ecosystem encompasses both the community (biocenosis) and the biotope, including the interactions of organisms with each other and their environment.

Habitat and Optimal Conditions

A habitat is the specific environment where an organism finds the necessary conditions for life. Optimal conditions, regarding a given environmental factor, are the values at which a species thrives, reproduces effectively, and experiences high offspring survival.... Continue reading "Understanding Ecosystems: Species, Niches, and Interactions" »

In the early 1990s, research on the human being began with the Human Genome Project. In April 2003, the entire nucleotide sequence of the human genome was completed. Today, we know that:

• Our haploid genome (all 23 different chromosomes that we possess) contains 3,000 million pairs of nitrogenous bases, which equates to about 30,000 genes.
• 99.9% of these genes are the same in all people: the differences between us do not represent more than 0.1% of the genome.
• 90% of the genome has no known coding function, which does not mean it has no function, such as gene regulation or various biological controls. It is thought that some of this DNA may correspond to genetic remains of our ancestors.

Applications of the Human Genome Project

The practical applications... Continue reading "Decoding the Human Genome: Applications and Biotechnology" »

Biotic Relationships

Biotic relationships are the interactions among living organisms in an environment. There are two main types of biotic relationships:

Interspecific Relationships

Interspecific relationships occur between organisms of different species. These include:

• Mutualism: A relationship where both species benefit. Example: Bees pollinating flowers.
• Commensalism: A relationship where one species benefits, and the other is unaffected. Example: Beetles feeding on mammal excrement.
• Inquilinism: A specific type of commensalism where one organism uses another for housing.
• Parasitism: A relationship where one species (the parasite) benefits at the expense of the other (the host). Example: Cochineals feeding on cacti.
• Predation: A relationship where

Non-Infectious Diseases

In addition to diseases caused by microorganisms, other diseases are caused by different reasons:

a) Diseases Affecting the Functioning of the Equipment

These include circulatory diseases, which affect the respiratory tract (such as asthma or bronchitis), and those that affect bones or joints (osteoarthritis and osteoporosis).

b) Cancer

This occurs when certain cells, for reasons not yet fully clarified, undergo a metamorphosis that makes them divide rapidly and uncontrollably. As a result, it creates a mass of abnormal cells, called a tumor, which causes the destruction of nearby tissue.

c) Deficiency Diseases

These are caused by a poor diet lacking in certain nutrients. Examples include vitamin deficiency or anemia.

d) Traumatic

Dental Pathology & Caries Vocabulary

• Pathology: The study of the effects of disease as seen in the structure and function of the body.
• Pathogen: Any organism capable of causing disease.
• Etiology: The study of the causes of disease, including all factors that may be involved in its development.
• Clinical Data: A collection of information gathered about a patient's disease.
  • Symptom: A subjective experience reported by the patient.
  • Sign: An objective finding observed by a clinician (e.g., blood pressure, swelling).
• Diagnosis: The identification of a disease through scientific evaluation of its physical signs, symptoms, medical history, laboratory tests, and other procedures.
• Prognosis: The predicted outcome of a disease, based on the patient's condition

1. Nutrients, Material, and Energy Source

Nutrients are the raw materials from which cells produce their own components. They replace lost components, facilitate growth, and produce new cells. Nutrients are the fuel for cells.

Other nutrients that reach the cells are used as fuel for cellular respiration. Glucose is the nutrient most used by cells as fuel. During cellular respiration, the following events occur:

• Oxygen consumption
• Release of energy usable by cells
• Production of carbon dioxide and water

Lipids and proteins can also be used as fuel to provide nutrients for energy. Cells use this energy to perform their functions.

Our body needs energy-containing nutrients to function; this energy is called chemical energy. Cellular respiration releases... Continue reading "Cellular Nutrition: Fueling Life, Energy, and Health" »

Chest pain is a critical symptom that can indicate various underlying conditions, ranging from benign to life-threatening. Two of the most serious causes are angina pectoris and myocardial infarction (heart attack). Understanding the differences and recognizing their symptoms is crucial for timely intervention.

Angina Pectoris

Angina pectoris is a clinical syndrome characterized by a sensation of precordial discomfort, pressure, or shortness of breath. It is typically precipitated by physical exertion and relieved by rest or sublingual nitroglycerin.

Angina occurs when the heart's workload and myocardial oxygen demand exceed the coronary arterial system's capacity to supply oxygen, leading to myocardial ischemia (a transient or permanent reduction... Continue reading "Chest Pain: Understanding Angina and Heart Attack Symptoms & Care" »

Plant Metabolism: Vital Processes

Like all living organisms, plants perform essential functions to facilitate growth, development, and reproduction.

The primary metabolic processes include:

• Absorption
• Circulation
• Respiration
• Transpiration

Absorption: Nutrient Uptake

Plants acquire nutrients not only from the soil but also from the air, primarily through their leaves, absorbing oxygen and carbon dioxide.

Water and dissolved minerals enter the roots via diffusion. Plants then convert these substances into organic molecules, such as:

• Glucose
• Fructose
• Starch
• Proteins
• Lipids (fats)

This conversion of minerals into organic compounds is unique to plants, certain bacteria, and microscopic algae. Consequently, wildlife, fungi, and protozoa rely on plants as their... Continue reading "Plant Metabolism: Absorption, Circulation, and Respiration" »

Understanding Parasites

A parasite is any living animal or plant that spends part or all of its existence inside or outside another living being (the host), feeding at its expense and potentially causing apparent or unapparent damage.

What is Parasitology?

Parasitology is the scientific discipline that studies organisms (parasites) that live inside or outside another host, extracting food and shelter. This association is not always harmful to the host.

Defining Parasitism

Parasitism occurs when a living organism (the parasite) lives on or in another organism of a different species (the host), from which it obtains nourishment. This relationship encompasses a wide range of organisms, from viruses to arthropods.

Zooparasites

Zooparasites are parasites... Continue reading "Parasitology Fundamentals: Relationships, Factors, and Disease Transmission" »