Biology Chapter on Metabolism, DNA, and Enzymes

Metabolism

• Metabolism is the sum of all chemical reactions occurring in a living organism.
• Catabolism breaks down molecules to release energy, while Anabolism uses energy to construct components of cells
• Energy currency of the cell is ATP.

DNA

• DNA is the hereditary material in all living organisms.
• Contains instructions needed for an organism's growth, development, and reproduction.
• Structured as a double helix, composed of four bases: adenine, thymine, cytosine, and guanine
• The sequence of these bases encodes genetic information, forming genes.
• During transcription, DNA is converted into RNA, which then translates into proteins through translation.
• DNA replication ensures that genetic information is passed on to the next generation.

Enzymes

• Enzymes are crucial proteins that act as catalysts in various biochemical reactions.
• They speed up chemical reactions by lowering the activation energy needed for the reaction to occur.
• Each enzyme is specific to a particular substrate, which it binds to form an enzyme-substrate complex.
• Without enzymes, many biological processes would occur too slowly to sustain life.
• Enzymes are sensitive to changes in temperature and pH, which can affect their activity.

Genetic Engineering

• Genetic engineering allows scientists to manipulate DNA for various applications, including gene therapy and agriculture.
• The process often involves the use of plasmids to transfer genes into host organisms
• CRISPR is a technique for precise editing of DNA sequences.
• The use of GMOs raises ethical and ecological concerns.

Metabolites

• Metabolites are the intermediates and products of metabolism.
• They play crucial roles in cellular functions.
• Primary metabolites are essential for growth and development.
• Secondary metabolites often have ecological functions.
• Examples of Primary Metabolites: amino acids, nucleotides, and carbohydrates
• Examples of Secondary Metabolites: alkaloids and flavonoids

Cell Signaling

• Cell signaling is a complex system of communication between cells.
• It involves a cascade of cellular events triggered by signals received from the environment or other cells.
• Cell signaling is critical for regulating cell growth, development, and response to environmental changes.

Apoptosis

• Apoptosis is a form of programmed cell death.
• Removes damaged or unwanted cells in a controlled manner.
• Apoptosis is essential for normal development, such as during embryogenesis.
• Dysregulation of apoptosis can lead to various diseases, including cancer and neurodegenerative disorders.

Immunology

• Immunology is the study of the immune system and its responses to pathogens.
• The immune system defends the body against infections and diseases.
• It recognizes foreign substances, known as antigens, and mounts an immune response to eliminate them.
• The two main types of immunity: innate immunity and adaptive immunity.
• Vaccination is a process that helps the body develop immunity against specific pathogens.

Electrophoresis

• Electrophoresis separates charged molecules, such as proteins and nucleic acids, based on their size and charge.
• It involves applying an electric field to a gel matrix.
• Smaller molecules move faster through the gel than larger ones.
• Commonly used in DNA analysis, including restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) applications.
• Electrophoresis is also used in protein analysis to determine protein purity and size.