Pro Vs Eu

Cells

the basic unit of structure and function of an organism that can perform all activities required for life

Prokaryotes

have no membrane-bound organelles and nucleus

eukaryotes

can be categorized into unicellular (single cell) or multicellular (consist of more than one cell) organisms

amoeba

is an example of a unicellular, eukaryotic organism

plant cell

has a rigid cell wall

animal cell

have more varied shapes than plant cells because of the absence of cell walls

prokaryotic cell

is a simple, single-celled (unicellular) organism that lacks a nucleus, or any other membrane-bound organelle.

nucleoid

Prokaryotic DNA is found in the central part of the cell: a darkened region called the

Prokaryotic Cells

Small, simple cells (1–5 µm), no membrane-bound organelles.

Nucleoid

region with circular DNA (no nucleus).

Cell wall

rigid, made of peptidoglycan (in bacteria) for shape & protection

Plasma membrane

controls passage of molecules.

Ribosomes

protein synthesis (smaller than the other)

Flagella

movement, attachment, protection.

Prokaryotic Cells

are efficient, simple life forms specialized for rapid reproduction and survival in diverse environments.

Eukaryotic Cells

Larger, complex cells (10–100 µm) with nucleus and organelles.

Eukaryotic Cells

allows specialized functions, complex multicellularity, and tissue formation.

Nucleus

contains DNA, control center.

Mitochondria

ATP (energy) production.

Endomembrane system

synthesis, processing, transport, digestion.

Cytoskeleton

shape, support, movement.

Rough ER

• Studded with ribosomes.

• Main site of protein synthesis (especially secretory proteins like enzymes, antibodies, hormones).

• Modifies proteins (folding, glycosylation).

• Sends proteins in vesicles to Golgi.

Smooth ER

• No ribosomes.

• Functions: lipid synthesis (phospholipids, steroids), detoxification (liver cells), and calcium ion storage (muscle contraction).

Golgi Apparatus

• Flattened membranous sacs (cisternae).

• Receives vesicles from ER.

• Functions: modifies, sorts, and packages proteins/lipids.

• Tags molecules with “postal codes” for delivery (inside cell or secretion).

• Produces lysosomes.

Lysosomes

• Membrane sacs filled with hydrolytic enzymes.

• Function: intracellular digestion.

  • Break down food particles (in single-celled organisms like Amoeba).

  • Recycle damaged organelles (autophagy).

  • Destroy bacteria (in white blood cells).

Vacuoles

Large vesicles with varied roles depending on organism:

• Plant central vacuole: water storage, maintains turgor pressure, stores ions/pigments/toxins.

• Contractile vacuole (in protists like Paramecium): pumps excess water out of cell.

• Food vacuole: stores engulfed food until digested (in Amoeba).