Topics 3, 4, and 5

Cellular Metabolism

Cellular Metabolism

The set of chemical reactions that occur within a cell, influenced by cell size and material exchange efficiency.

Surface Area-to-Volume Ratio (SA:V)

A critical factor that affects cellular function, where a higher ratio allows for better material exchange.

Plasma Membrane

A selective barrier that regulates the entry and exit of substances, maintaining homeostasis within the cell.

Phospholipids

The fundamental building blocks of the plasma membrane, consisting of a hydrophilic head and two hydrophobic tails.

Membrane Fluidity

The ability of the plasma membrane to remain flexible, influenced by temperature and the presence of unsaturated fatty acids.

Fluid Mosaic Model

A description of the plasma membrane as a dynamic structure with a phospholipid bilayer and embedded proteins.

Integral Proteins

Membrane proteins that are embedded within the lipid bilayer, often involved in transport and communication.

Peripheral Proteins

Membrane proteins that are loosely attached to the membrane's surface, involved in signaling and maintaining cell shape.

Glycolipids

Carbohydrates bonded to lipids in the membrane, contributing to stability and functionality.

Glycoproteins

Carbohydrates attached to proteins, playing a role in signaling and cell recognition.

Cell Wall

A rigid structure surrounding plant cells, providing support and protection, primarily composed of cellulose.

Plasmodesmata

Channels in plant cells that connect adjacent cells, facilitating communication and material transport.

Turgor Pressure

The pressure exerted by water inside the plant cell, maintained by the cell wall and essential for plant health.

Challenges of Larger Cells

Larger cells face difficulties in nutrient intake and waste expulsion due to a decreased SA:V ratio.

Evolutionary Advantage of Smaller Cells

Smaller cell sizes are favored in many organisms for efficient metabolic processes and material exchange.