of the life
Cell is the smallest unit of life,
the smallest structure that is classified as a
and is often called the building block of life
- but I dont think this description is clear enough-
The cell is the basic structural and functional unit
of an organism
What does it mean?
All living things are
made up of one or more
All living cells come from
pre-existing cells by
The activity of an organism
the total activity of individual cells.
All cells are basically the same in chemical composition
in organisms of similar species.
Anton van Leuwenhoek
1673 - Anton van Leuwenhoek used a
handmade microscope to observe
pond water & discovered
He called them “animalcules”
He also observed blood cells from fish, birds, frogs, dogs,
Therefore, it was known that cells are
found in animals as well as plants
observó (con un
superaba el de los
Discovery of Cells – Robert Hooke
1665 – English scientist, Robert Hooke,
discovered cells when he was looking
through one of the first microscopes
Looked at a thin slice of cork and
described what he saw as “tiny boxes or
Named the boxes “cells” as they reminded
him of the cells in monasteries
Thought cells only existed in plants
Development of Cell Theory – 1800’s
1833 – Robert Brown
Observed the nucleus in the epidermis of an orchid
Schleiden and Schwann
1838 - Matthias Schleiden, a German
professor of botany, identified the first
plant cells and concluded that all parts
of a plant is made of cells
1839 – Theodor Schwann, a German
zoologist and a close friend of
Schleiden, stated that all animal
tissues are composed of cells.
1855 – Rudolf Virchow, German
Proved that cells come from other
cells, not from non-living matter
“Omnis cellula e cellula”
The Complete Cell Theory
Putting it all together:
The 3 Basic Components of the Cell Theory were now
1. All living things are composed of one or more cells. (Schleiden &
2. The cell is the basic unit of structure and function in all living
things (Schleiden & Schwann, 1838-39)
3. All cells come from preexisting cells (Virchow, 1858)
¿Por qué las células suelen ser pequeñas?
El cubo de 4 cm de arista,
los ocho cubos de 2 cm de
arista y los 64 cubos de 1
cm de arista tienen todos
el mismo volumen. Pero al
dividir el volumen en
porciones, la superficie
Al ser las células pequeñas
tienen mayor superficie
(aumentando la eficacia de
entrada y salida de
Cells have lots of
different functions but
they are often
specialised to do a
For this reason each
type of cell has
that make it well
adapted at carrying
out its functions.
We are going to study in detail just
a few of the organelles in animal cells:
* nucleus and DNA
* ER + Golgi apparatus
glucosa, fructosa y galactosa
No requieren digestión pues son pequeñas moléculas.
De fórmula C6H12O6
as simbolizaremos como
Se disuelven en agua y tienen sabor dulce
sacarosa y lactosa, uniones de dos monosacáridos
Requieren digestión hasta monosacáridos para poder entrar en las célul
Se disuelven en agua y tienen sabor dulce.
Las simbolizaremos como
La ecuación anterior
solo tiene sentido...
considerando el resultado aprovechable
por los seres vivos cuando realizan el proceso:
Nucleus role: containing DNA
DNA carries the information for making
all of the cell's proteins.
Ribosome role: producing proteins.
These proteins perform all of the functions
of a living organism
(DNA) is the master
molecule of every cell.
It control the making
of other molecules
Although it may look
complicated, the DNA in a
cell is just a sequence
made up of four different
parts called nucleotides.
Imagine a set of blocks
that has only four shapes,
or an alphabet that has
only four letters. DNA is a
long string of these blocks
DNA carries the information for making all of the
These proteins carry out all of the functions of a living
When the cell reproduces, it has to pass all of this information
-copy of DNA- to the daughter cells.
In DNA, each protein is encoded by a gene (a specific
sequence of DNA) that determines the order of amino acids
that must be put together to make a protein.
A protein is made of a long chain of chemicals called
Depending on the sequence of amino acids,
trillions different proteins
20 types of amino acids in organisms
Proteins have many functions:
Enzymes that speed up chemical reactions (such as digestive enzymes)
Structural proteins that are building materials (such as collagen and nail keratin)
Transporting proteins that carry substances (such as oxygen-carrying haemoglobin in blood)
Contraction proteins that cause muscles to compress (such as actin and myosin)
Hormones - chemical messengers between cells (including insulin, growth hormone etcetera)
Protective proteins - antibodies of the immune system, clotting -coagulantes- proteins in blood
The particular sequence of amino acids in the protein chain is
what makes one protein different from another. This sequence
is encoded in the DNA where one gene encodes -CODIFICAfor one protein.
The particular sequence of amino acids in the chain is what
makes one protein different from another. This sequence is
encoded in the DNA where one gene encodes for one protein.
two amin oacids so far -hasta ahora: M-R
making a new protein.
A ribosome is made up of two round parts,
the smaller subunit and the bigger subunit
Instructions in DNA
The third amino acid is about to
join the two previous amino acids