CBSE · Class 10 · Biology · Chapter 5

Cell — The Basic Unit of Life — Formula Sheet

Board Formulas

7 formulas

1.Cell Theory (Schleiden and Schwann)★
$All living organisms = one or more cells; Cell = basic unit; New cell = pre-existing cell$
Refined by Rudolf Virchow. Three tenets — memorise all three.
2.Prokaryote vs Eukaryote★
$Prokaryote (no nucleus) vs. Eukaryote (true nucleus)$
Prokaryotes: bacteria, cyanobacteria. Eukaryotes: everything else — plants, animals, fungi, protists.
3.Diffusion
$Movement \propto concentration gradient (high \to low)$
Passive movement of molecules across a membrane, from high to low concentration.
4.Osmosis★
$Solvent movement across semi-permeable membrane: dilute \to concentrated$
Special case of diffusion — only the SOLVENT (water) moves. Bathing raisins in water shows osmosis.
5.Function of Mitochondrion
$Glucose + O_{2} ⟶ A T P (energy currency)$
Power-house of the cell — site of aerobic respiration; has its own DNA and ribosomes.
6.Function of Chloroplast
$C O_{2} + H_{2} O sunlight glucose + O_{2}$
Only in plant cells — traps sunlight for photosynthesis. Contains chlorophyll.
7.Function of Ribosome
$mRNA ⟶ Protein$
Site of protein synthesis. Present in all cells (prokaryote + eukaryote). Attached to rough ER.