Physiology & Diagram Dàil Phlanntaichean

Physiology & Plant Cell Diagram

• Plants cells, tissues and organs function
• Chemistry of their functions
• Crucial to understanding plant structure and function

Plant Cell Diagram Details

• Ribosomes: Control all cell functions
• Nucleolus: Stores solutes, critical for osmotic potential
• Vacuole: Large central vacuole, determines osmotic potential
• Chloroplast: Site of photosynthesis
• Mitochondria: Site of respiration
• Cell membrane: Controls what enters and leaves the cell; selectively permeable

Plasma Membrane Transport

• Transport Proteins: Embedded in the membrane, responsible for selective transport of solutes
• The membrane is selectively permeable, allowing certain substances through while excluding others

Biological Membranes

• Primarily composed of a phospholipid bilayer with proteins embedded within.
• The composition varies between membranes

Diffusion

• Movement of particles due to kinetic energy, from high concentration to low concentration
• Important mechanism for molecules to move in and out of cells.
• Passive simple diffusion: Small, nonpolar substances
• Passive facilitated diffusion: Large substances, needing protein channels (carriers) for assistance.

Solubility of Substances

• Substances with greater affinity for oily materials, such as lipids, pass more rapidly.
• Substances with equal lipid solubility, the larger molecules permeate more slowly than the smaller ones.

Permeability to ions

• Although ions (charged particles) are small, they diffuse through membranes at a slower rate compared to non-ionized substances.
• Cells can still uptake ions even if concentration is higher inside the cell, requiring energy (active transport).

Active Transport

• Movement of substances against concentration gradient, requiring metabolic energy and transmembrane protein pumps.
• Cells maintain a consistent internal environment using this mechanism.

Selective Uptake of Ions

• Living cells have the ability to selectively absorb and accumulate certain ions.
• Monovalent cations (like potassium) often absorbed faster than polyvalent cations (like calcium)

Osmosis

• Movement of water across a selectively permeable membrane from area of high water potential to low water potential.
• Crucial for maintaining turgor pressure in plant cells, important for structural support.
• Water potential determines the direction of osmosis.

Plasmolysis

• Loss of water from plant cells when placed in a hypertonic solution leading to shrinkage, damaging the cell wall.
• This process can be reversed by placing cells in a hypotonic solution.

Importance of Osmosis to Plants

• Essential for water entry into plant cells from surroundings
• Crucial for movement of cells
• Maintains turgor pressure
• Crucial aspects of growth and cell regulation etc.

Colloids

• Suspension: Larger particle concentration; settle out over time
• Colloid: Intermediate particle size; do not settle out
• Solution: Smallest particle concentration; completely dissolved particles

Colloidal Properties

• Particles size: From 1–100 nanometres
• Electrical charges: Particles have either positive or negative charges
• Attraction/Repulsion: Similar charges repel, dissimilar charges attract.
• Stability: Colloidal suspensions are generally stable due to electrostatic repulsion, preventing clumping
• Visibility: Can be seen by naked eye/microscope depending on concentration
• Tyndall effect: Scattering of light by colloidal particles

Precipitation & Flocculation

• Removal of dispersed particles from solution by adding electrolytes or substances with opposite electrical charges
• Causes aggregation and settling of colloidal particles
• Flocculation is the clumping of particles in a colloid

Filterability & Brownian Movement

• Colloidal particles pass through ordinary filter paper without being separated
• Small particles display Brownian movement (constant random motion) in a liquid medium

Gelation & Solation

• Gelation: Transition from sol (liquid) to gel (semi-solid)
• Solation: Transition from gel back to a sol
• Both processes often occur repeatedly due to fluctuating physiological conditions.

Surface Area & Size

• Subdividing a material into smaller colloids dramatically increases its surface area
• Increased surface area helps facilitate interactions between dispersed particles and dispersion medium

Imbibition

• Ability of certain substances to absorb water; especially important in plant cells for processes like seed germination.
• Essential for plants' functioning.

Tyndall Effect

• Scattering of light by colloidal particles
• Important for distinguishing between solutions and colloids

Gheibhear beachdan air obair ceallan phlanntaichean agus an ceangal eadar ceimigeachd agus structar. Tha an deilbh a' sealltainn mar a thaghas na ceallan agus na h-organan a tha cudromach airson a' mhodh-obrach aca. Leigidh e le sùil a thoirt air obair nan ceallan, a' gabhail a-steach ribosomes, chloroplasts, agus mitochondria.