Cellular Transport and Plasma Membrane Structures
Macrotransport: Cellular Uptake and Release
Characteristics of Macrotransport
- Transport of large molecules/particles into and out of the cell
- Involving deformation/folding of the plasma membrane
Types of Macrotransport
- Endocytosis: Transport into the cell
- Pinocytosis (“cell drinking”)
- Phagocytosis (“cell eating”)
- Exocytosis: Transport out of the cell
Endocytosis
Phagocytosis vs. Pinocytosis: Key Differences
- Size of the material engulfed:
- Phagocytosis: > 250 nm vacuoles
- Pinocytosis: < 150 nm vesicles
- Size
Stem Cells: Understanding Types and Therapeutic Potential
Understanding Stem Cells: Types and Applications
A stem cell is an undifferentiated cell that can self-renew and differentiate into various specialized cell types. Stem cells serve as a continuous source for the diverse cells that constitute the tissues and organs of animals and plants. There is significant interest in stem cells due to their powerful potential for developing therapeutic approaches to replace damaged or diseased cells resulting from various disorders and injuries.
Stem cells are totipotent
Read MoreDNA Sequencing Technologies: Methods and Applications
DNA Sequencing Methods and Technologies
Classical Sequencing: The Sanger Method
DNA sequencing methodologies can typically be classified into two major categories: classical sequencing techniques and high-throughput sequencing approaches. A prime example of the classical approach is the Sanger sequencing method. First introduced in 1977 by British biochemist Frederick Sanger and his colleagues, Sanger sequencing holds the distinction of being among the earliest DNA sequencing technologies.
This technique
Read MoreEnzyme Catalysis: Mechanisms, Cofactors, and Regulation
Factors in Enzyme Catalysis
Proximity and Orientation
Enzymes act by increasing the effective concentrations of substrates, bringing them closer with appropriate guidance of reactive groups.
Surface Phenomena
The properties of the active site can be considerably different from the surrounding medium and more favorable for a particular reaction to occur.
Strain and Distortion Factors
The presence of groups capable of providing reactive mechanisms of lower activation energy. These act by general acid-base
Read MoreRecombinant DNA Technology: Insulin, Somatropin, and Protein Engineering
Insulin
Insulin is a classic example of a naturally occurring protein produced by recombinant technology. Human insulin was the first recombinant protein commercially produced for therapeutic use. Before the availability of recombinant insulin, diabetic patients relied on insulin purified from the pancreases of pigs and cows, which occasionally resulted in serious immune reactions. Recombinant human insulin has dramatically improved the therapy for diabetes. Human insulin is expressed as a precursor
Read MoreEssential Plant Biology: Processes & Adaptations
Water Absorption in Plants
Plants absorb water primarily through their roots, specifically through tiny, hairlike structures called root hairs. These root hairs significantly increase the surface area of the root, maximizing contact with the soil water.
Mechanism of Water Uptake
The primary mechanism of water absorption is osmosis. Osmosis is the movement of water molecules from a region of higher water concentration (lower solute concentration) to a region of lower water concentration (higher solute
Read More