BIOLOGY - Cell

The Building Block Of Life

CELL

The basic structural and functional unit of life, comprising various organelles and surrounded by a plasma membrane. Cells can be unicellular or multicellular, and they carry out essential processes necessary for organism survival.

PLASMA MEMBERANE

The outer boundary of a cell that regulates the movement of substances in and out, maintaining homeostasis and providing protection .Also known as cell membrane and it is selectively permeable membrane as it is smooth and flexible and allow only few substances to pass through it and it is very thin , about 7 - 10 nm and made up of lipids and protein .

UNICELLULAR

it is a single cell that performs all tasks independently and their life span is short and they reproduce by asexual reproduction.

MULTICELLULAR

composed of multiple cells that are specialized for different tasks allowing greater complexity in carrying out life processes. The life span of each cell is very long and here only germ cell can reproduce other than somatic.

BIOLOGICAL HEIRCHEY

systematic arrangement of living organisms in descending order of complexity - Cell - Tissues - Organ - Organ system - Organism

• LIMIT OF RESOLUTION

Smallest path between two points at which they are distinguished as separate entities under a microscope.Limit of resolution of a human eye is 0.1mm.

FLUID MOSAIC MODEL

• it describes the structure of cell membrane as a flexible layer made up of lipids with embedded proteins In this the lipids are structured as heads upward and the 2 tails downward and this row creates lipid bilayer and proteins are embedded in them and act like gatekeepers because substance pass through it.

OSMOSIS

special form of diffusion - the movement of water molecules through selectively permeable membrane from a region of lower water concentration to higher water concentration.

ISOTONIC SOLUTION

solute concentration of extracellular medium = solute concentration of intracellular medium - isotonic solution

HYPOTONIC SOLUTION

solute concentration of extracellular medium <solute concentration of intracellular medium - hypotonic solution

HYPERTONIC SOLUTION

solute concentration of extracellular is > solute concentration of intracellular medium - hypertonic solution

DIFFUSION

movement of particle from region of higher to lower concentration.

NUCLEUS

PROKARYOTIC CELL

EUKARYOTIC CELL

CELL WALL

CYTOPLASM

MITOCHONDRIA

RIBOSOMES

ENDOPLASMIC MEMBERANE

GOLGI APPARATUS

LYSOSOME

PLASTIDS

VACUOLES

PLASMOLYSIS