Cellular Energy and Macromolecules: Roles and Classification
Classification and Roles of Biological Macromolecules
Carbohydrates: Classification and Biological Roles
Carbohydrates are essential biomolecules classified based on the number of sugar units:
- Monosaccharides (Simple Sugars): Examples include glucose, fructose, and galactose.
- Disaccharides (Two Monosaccharides): Examples include sucrose, lactose, and maltose.
- Polysaccharides (Many Monosaccharides): Examples include starch, glycogen, and cellulose.
Biological Roles of Carbohydrates
- Energy Source: They serve
Molecular Genetics: DNA Structure, Replication, and Repair
DNA Structure and Packaging
- Phosphate Group: Gives DNA its acidic properties.
- DNA Orientation: Written in the 5′ to 3′ direction.
- Complementary Pairing: Purine pairs with pyrimidine (A-T, G-C) ensuring constant width.
- Adenine (Purine) pairs with Thymine (Pyrimidine) via 2 hydrogen bonds.
- Guanine (Purine) pairs with Cytosine (Pyrimidine) via 3 hydrogen bonds.
- Backbone: Antiparallel structure; sugars are oriented differently to allow base pairing. The helix shields hydrophobic bases. There are approximately
Animal Biology Fundamentals: Cells, Tissues, and Systems
Animal Biology Fundamentals: Eukaryotic Cells
Nucleus: Holds genetic material. Protected by a double membrane that separates it from the cytoplasm.
Vacuoles: Small sacs that store various substances.
Lysosomes: Produced by the Golgi apparatus; responsible for digesting materials inside the cell.
SER (Smooth Endoplasmic Reticulum): Produces lipids and aids in detoxification (removal of toxic substances).
Mitochondria: Have two membranes; break down glucose to release energy via cellular respiration.
Cytoplasm:
Fundamental Concepts of Biology: From Cells to Ecosystems
Characteristics of Living Organisms
- Sensitivity
- Organisms respond to diverse stimuli.
- Adaptation
- All living organisms exhibit a “fit” to their environment.
- Metabolism
- This refers to the chemical reactions that occur within living organisms to maintain life.
- Homeostasis
- The ability of an organism to maintain constant internal conditions.
- Organization / Order
- Organisms are highly organized structures. The cell is the basic unit of life.
Levels of Biological Organization
- Population
- A group of organisms of the
Milestones in Genetics: History, Concepts, and Disorders
Key Historical Discoveries in Genetics (8000 B.C. – 1962)
| Year | Discovery / Event | Scientist(s) Involved |
|---|---|---|
| 8000–1000 B.C. | Humans knew sexual reproduction caused variation (used in selective breeding). | Ancient humans |
| 1856–1863 | Hybridization experiments on garden peas (basis of inheritance laws). | Gregor Johann Mendel |
| 1865 | Publication of Mendel’s work, “Experiments on Plant Hybridization”. | Mendel |
| 1866 | First description of Down Syndrome. | Langdon Down |
| 1891 | Discovery of the X-body (X chromosome) during spermatogenesis |
Viral Immunity and Pathogenesis: Host Defense Mechanisms and Infection Outcomes
Host Defense Mechanisms Against Viruses
Innate, Intrinsic, and Adaptive Immunity
- Innate Immunity: Non-specific, immediate response. Uses Pattern Recognition Receptors (PRRs) to detect Pathogen-Associated Molecular Patterns (PAMPs).
- Intrinsic Immunity: Always present in cells (pre-existing defenses).
- Examples: TRIM proteins, MxA, Tetherin, autophagy, apoptosis.
- Adaptive Immunity: Specific, develops after infection.
- Two arms: T cells (cell-mediated) and B cells (antibody-mediated/humoral).