Understanding Food, Nutrients, and Biological Processes
Understanding Food and Nutrients
Foods are natural or processed substances containing various nutrients. Humans consume them to satisfy hunger or for other reasons. They can be plant-based, animal-based, liquids, or solids.
Pursuing and obtaining food is fundamental to survival. Therefore, humans have had to adapt to their environment or fight to ensure their survival.
Carbohydrates
Carbohydrates are derived from plants and cereals. They are the primary source of energy for living things. Glucose is the most important carbohydrate at a biochemical level.
Energy Foods
Energy foods primarily provide energy to the body. These are mainly carbohydrates and lipids.
Plastic Foods
Plastic foods provide materials for growth and body repair. These are mainly proteins.
Proteins
Proteins are a group of substances containing nitrogen, with carbon, hydrogen, nitrogen, and oxygen in their molecules.
Plant Foods
Plant foods come from the edible parts of plants.
Animal-Origin Foods
Foods of animal origin are sources of high-quality protein. They are also rich in protein and minerals. Examples include milk, fish, meat, eggs, and poultry.
Energy Value
Energy value is the amount of energy that can be provided when burned in the presence of oxygen.
Vitamins and Minerals
Vitamins and minerals are micronutrients needed in small quantities daily.
Importance of Water
Water is essential for quenching thirst and preparing food. It is also vital for agriculture, animal husbandry, manufacturing, and energy production.
Importance of Minerals
Minerals are as important as vitamins for maintaining good health.
RNA and DNA
RNA (messenger ribonucleic acid) produces polypeptides that form enzyme proteins.
DNA: When a cell is not dividing, the chromosomes in the nucleus are not visible and appear as thin filaments.
Biological Variations and Processes
Continuous Variations
When classifying individuals by weight and height, the subdivisions become more arbitrary.
Staple Variations
Staple variations never go through intermediates. Examples include hair color and blood type.
Mutations
Mutations are caused by sudden changes at the gene or chromosome level.
Types of Mutations:
- Genetic mutation
- Somatic mutations
- Germline mutation
- Chromosome mutation
Genotypic Variation
A variation in the genotype causes a corresponding variation in the phenotype if the character is dominant.
Digestion
Digestion is a process in humans that begins in the mouth, passes through the esophagus, enters the stomach, then the small intestine, liver, and kidneys, followed by the large intestine, and finally the colon.
Enzymes
Enzymes are responsible for breaking down ingested food and extracting vitamins and minerals.
Darwin’s Theory: 5 Principles
- The number of descendants of plants and animals is higher than their parents.
- Despite this trend, the number of individuals in each species remains relatively constant.
- Only a small number of individuals reach maturity and must compete for survival.
- Individuals of each species differ in small, inherited features.
- Harmful mutations may cause an organism to die before reaching sexual maturity, preventing transmission.
Adaptation
Adaptation is the ability of an organism to live and adjust to an environment. It is divided into structural, physiological, and behavioral adaptations.
Adaptations can be simple (controlled by a few genes) or complex (useful in many different situations).
Adaptation by Chance and Necessity
Necessity: Mammals respond to changes in external temperature to maintain a constant body temperature.
Random: Some individuals are better equipped to meet new life necessities.
Isolation
Isolation is the basic criterion used in modern biology to determine if two individuals are of the same species. It is based on their ability to interbreed and produce fertile offspring.
Types of Isolation:
- Geographic isolation
- Ecological isolation
- Seasonal isolation
- Physiological isolation