Biology Chapter on Filtration and Active Transport

Study Notes

Filtration involves movement through a membrane from high to low hydrostatic pressure, driven by blood pressure in the body.
Active transport utilizes ATP to move substances against concentration gradients via solute pumps.
Active transport is essential for amino acids, sugars, and ions.
Vesicular transport includes exocytosis (expelling substances) and endocytosis (ingesting substances), with endocytosis further categorized into phagocytosis, pinocytosis, and receptor-mediated endocytosis.

Interphase is the extensive metabolic phase of the cell cycle.
Mitosis divides the nucleus into two identical daughter nuclei, each with the same genetic material.
Cytokinesis follows mitosis, dividing the cytoplasm to form two separate cells.
Mitosis phases include:
- Prophase: Chromatin condenses into chromosomes, centrioles move apart, and the nuclear envelope disintegrates.
- Metaphase: Chromosomes align at the metaphase plate.
- Anaphase: Sister chromatids separate and move to opposite cell poles.
- Telophase: Chromatids revert to chromatin, the nuclear envelope reforms, and nucleoli reappear.

A cell is the fundamental structural unit of all living organisms; its activities influence overall organism function.
Nucleus contains:
- Nuclear envelope: A double membrane barrier.
- Nucleoplasm: Jelly-like fluid suspending nuclear elements.
- Nucleolus: Ribosome assembly site.
- Chromatin: Genetic material in non-dividing cells; forms chromosomes during division.

Cells exhibit irritability, respond to stimuli, digest, excrete wastes, grow, reproduce, and metabolize.
Passive transport mechanisms include:
- Diffusion: Movement from high to low concentration, requiring no ATP.
- Osmosis: Water diffusion across membranes.
- Facilitated diffusion: Requires protein channels or carriers.

Epithelial Tissue: Covers all body surfaces and has functions in protection, absorption, filtration, and secretion.
Characteristics include:
- Closely packed cells with cell junctions.
- Apical surface (free edge) and basal surface (attached via basement membrane).
- Lacks blood supply but regenerates easily.
Classified as simple or stratified based on layers, and further by shape (squamous, cuboidal, columnar).

Connective tissue is the most abundant tissue type, serving to protect and support organs.
Key features include:
- Variation in blood supply.
- Extracellular matrix composed of ground substance and fibers.
Types include bone, cartilage, dense connective tissue, loose connective tissue (such as areolar and adipose connective tissue), and blood.