Human Digestion and Respiration Processes
Digestive Process
Enzymes are unseen substances produced by the body that mix with food. In the digestive tract, a series of chemical reactions take place, called chemical digestion.
Mastication: Mechanical process of crushing food into smaller pieces.
Tongue: Involved in moving food to other teeth.
Salivation: When we put food in our mouth, salivary glands produce saliva, a liquid that mixes with food to form the food bolus. Saliva has three functions:
- Starts the chemical digestion of carbohydrates
Revolutionizing Genetics and Biotechnology
Revolution in Genetics and Biotechnology
Introduction:
Genetic discoveries in the 21st century have led to the development of techniques such as:
- In vitro fertilization
- Cloning
- Gene therapy (curing diseases by manipulating genes)
Genetics has evolved significantly thanks to the discovery of DNA.
DNA and RNA
These are nucleic acids, core components of the cell.
Chemical Composition:
- Functions of DNA: To maintain genetic information and pass it on to daughter cells during cell division.
- Why are we different
Understanding the Excretory and Urinary Systems
Excretory System
The excretory system is responsible for removing toxins and wastes from our body.
The excretory system consists of the urinary tract, lungs, and skin.
The excretory system should be added to the large intestine or colon, waste that accumulates in the feces to be excreted through the anus.
Urinary System
The excretory system is a set of organs responsible for the elimination of nitrogenous waste products of metabolism known as urine, in the form of urea and creatinine. Its architecture
Plant Biology: Nastic Movements, Reproduction, Pollination, Nutrition
The Nasties: Nastic Movements
Nastic movements in plants are responses to stimuli, determined by the plant’s organ structure. These reactions are rapid and reversible, triggered by various stimuli like light, temperature, or touch. Examples include photonasty (response to light) and thigmonasty (response to touch).
Reproduction in Bryophytes
Bryophytes are seedless, nonvascular plants that require a moist environment for growth and reproduction. The dominant phase is the gametophyte (sexual phase),
Read MoreEcosystem Dynamics: Energy Flow and Adaptation
Ecosystems: Energy and Matter
Ecosystems function as factories requiring energy and matter. Matter exists as abiotic (inert) and biotic (organic) components. Energy, primarily from the sun, is captured by autotrophs (producers) through photosynthesis. Energy is lost as heat or waste. Heterotrophs (consumers) obtain energy by consuming organic matter. Consumers include herbivores (primary), carnivores (secondary and tertiary), and decomposers (fungi and bacteria).
Trophic Relationships:
- Food chains
Protein Structure, Function, and Analysis
Proteins
Formed by amino acids (aa) with an amino group (bases) and a carboxyl group (acid).
The essential aa are synthesized by the body.
AA differ in the structure of side chains (R groups).
Amphoteric character: behave as charged or uncharged particles depending on the pH.
Acid pH
Positive charge
Basic pH
Negative charge
Hybrid or zwitterion ion: dipole with zero charge.
PI (Isoelectric Point)
- aa with zero net charge
- aa > 2 units per PI: net negative charge
- aa < 2 units per PI: net positive charge
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