Cell Biology: Macromolecules, Processes, and Genetics
Key Concepts in Cell Biology
- Water’s hydrogen bonds give it unique properties like cohesion, adhesion, and surface tension.
- Monomers form polymers through dehydration synthesis, while hydrolysis breaks polymers into monomers.
- Nucleic acids (DNA and RNA) store genetic information and are composed of nucleotides (deoxy/ribose, phosphate, and a nitrogen base).
- Proteins are made of amino acids, and the polypeptide sequence determines their structure and function.
- Simple sugar monomers combine to form complex
Understanding Biospheres, Ecosystems, and Biomes
- What is a biosphere: The biosphere is the life zone of the Earth.
- What is an ecosystem: An ecosystem consists of the organisms that live in a particular area, the relationships between them, and their physical environment.
- What are biomes: Biomes are the large-scale ecosystems of the world.
- What is the biocenosis: It is the set of living beings in the ecosystem.
- What are biotic factors: They are the effects that other organisms have on a living being in its environment.
- What is a biotope: The biotope
Cell Cycle: Mitosis, Meiosis, and Biological Significance
Cell Cycle
The cell cycle is divided into two main phases: division (mitosis and cytokinesis) and interphase (the period between divisions).
Interphase
Interphase is the period between two successive cell divisions. It consists of the following phases:
- G1 Phase: Preparation for the S phase. This phase occurs at the end of the last division and involves preparation for DNA duplication. The restriction point in G1 determines whether the cell will proceed to the S phase.
- S Phase: Synthesis phase, involving
Immune Memory, Health, and Genetic Engineering Concepts
Immune Memory and Immunity
Immune memory is what allows the rapid recognition and response to infections. It is a unique and crucial role of the immune system. Immunity is the ability of a person to prevent infection or disease.
Antigens and Antibodies
Antigens: These are proteins or polysaccharides found on the surface of viruses and other pathogens.
Antibodies: These are proteins produced by lymphocytes, which belong to the immune system and act as a defense against viruses, bacteria, parasites, and
Read MoreRNA Transcription: Process and Stages
RNA Transcription: A Detailed Look
Transcription is the process of RNA synthesis, which occurs inside the cell nucleus. This process requires:
- A DNA strand that acts as a template.
- RNA polymerase (RNA-pol) enzyme.
- Ribonucleotide triphosphates (A, G, C, and U).
Ribonucleotides are linked via phosphodiester bonds. The overall process consists of three main stages: initiation, elongation, and termination.
Initiation
RNA polymerase recognizes specific sequences in the DNA that will be transcribed. These sequences
Read MoreExcretory and Nervous Systems: Human Body Functions
Theme 5: The Excretory System
The excretory system includes organs responsible for eliminating waste and foreign substances. It also maintains vital signs, such as the amount of water in the organism and blood acidity.
- Liver: Eliminates products resulting from the destruction of blood hemoglobin.
- Respiratory System: Expels carbon dioxide.
- Sweat Glands: Located in the skin, they produce sweat, which cools the skin when the temperature is high.
- Urinary System: Eliminates waste products through urine.