Cell: The Unit of Life

Exploring about Cells and its fundamentals parts in this specific unit, covering all essential data.

Define the term Biology

It is the study of ‘LIFE’, ‘Living organisms’, and
‘Living processes (Physiology).

What do you mean by Reductionist Approach?

It is a physio-chemical approach (using
physical/chemical reactions) to understand physiology
and behavioural aspects at the MOLECULAR LEVEL.

What unifies all living organisms on Earth?

CELL THEORY

What is the DEFINING feature of ‘all’
living organisms?

Cellular organisation

BRANCHES OF BIOLOGY ARE:

• Botany: Study of Plants.
• Zoology: Study of Animals

what is Ramachandran plot?

concept of structural biology used to determine value of phi( b/w n and c ) and psi (b/w c and c bond) bonds present in amino acids

RESEARCH AND INSPIRATION OF RAMACHANDRAN'S WORK

Triple helical structure of collagen published in Nature in 1954 and was inspired by Linus Pauling who gave alpha and beta structure.

WHO FOUNDED MADRAS SCHOOL OF CONFORMATIONAL ANALYSIS OF BIOMOLECULES

RAMACHANDRAN

Ramachandran was born near

COCHIN

What is Cell?

Cell is the basic structural & functional unit of life.

How does Electron Microscopy work?

It uses electron ( e−) beams which have a very low
wavelength and provides high magnification and high resolution image (the
ability to see 2 close points differently).

Type of organisms on the basis of number of Cells.

Unicellular organisms and Multicellular organisms

Who Discovered the α-helix and β-sheet
structures of proteins.

Linus PAULING

The range of plotted values
for ψ & ϕ angles in the Ramachandran Plot.

-180° to +180°

1950 to 1960

Time Period for the advancement
in electron microscopy

Anton Von Leeuwenhoek

First saw and described a
live motile cell.

Who discovered the nucleus?

Robert brown

Who Reported that cells had a thin
outer layer (known today as the plasma membrane)?

Theodore Schwann.

In which year Ramachandran’s collagen structure was
published in ‘Nature’?

1954

Which cells can survive independently and perform ‘all’
essential functions of life?

Unicellular Cells can survive independently and perform ‘all’
essential functions of life.

WHICH CELLS exhibit division of labour (different cells do
different tasks)?

Multicellular cells

Who studied plant cells and noted
that the unique cell wall is present over the cell
membrane.

Theodore Schwann

Who gave the hypothesis that the bodies of all plants
and animals are composed of cells and products of
cells.

Theodore Schwann

Who gave the term ‘ANIMALCULES’.

Anton Von LEEUWENHOEK

Who Modified the theory to its
final shape

RUDOLF VIRCHOW

Omnis cellula-e-cellula

New cells arise from the division of pre -
existing cells.

WHICH ORGANISMS do not follow cell theory

Viruses, Viroid, and
prions are ‘ACELLULAR’ (lack their own cell
structure)

What is the size of SMALLEST CELL?

Only 0.3 μm in
length.

What is the size of BACTERIA?

Typically, 3 to 5 μm in length.

Name the largest isolated single cell.

Ostrich egg

What is the longest cell present in the human body?

Neurons

Size 7 µm; round, biconcave disc; transports oxygen.

Red Blood Cell (RBC)

10–20 µm; amoeboid shape; provides defence.

White Blood Cell or WBC

2–4 µm; plate‑like; helps in blood clotting

Platelet

Size order between WBC, RBC and Platelets?

WBC > RBC > Platelet

FULL FORM OF PPLO?

Pleuro‑pneumonia‑like organism

Size of PPLO?

0.1 μm

SIZE of Typical bacteria?

Length 3–5 µm, width 1–2 µm.

Size of Typical eukaryotic cell ?

10–20 µm.

WHICH organisms have this 0.02–0.2 µm?

Viruses

WHAT IS THE TIME PERIOD OF DIVISION OF E.Coli?

E. coli divides every 20 min.

WHAT IS THE TIME PERIOD OF DIVISION OF HUMAN CHEEK CELL?

Human cheek cell divides every 24 h.

FUNCTION OF NEURONS /NERVE CELLS?

Transferring signals

Dead cells which transport water?

TRACHEID

Function of TRACHEID?

Transporting water

Name the cell which is Round/oval; chloroplasts at boundary?

Mesophyll cells

Name the cell which is Long, slender, pillar‑like with basal nucleus?

Columnar epithelial cell