From Cell To Organism

Everything is composed of cells, every tissues are composed of cells, every organs are composed of tissues, every organ systems are composed of organs and every organism are composed of organ systems that works

together to form an organism!

Cell is the “building blocks of life” .Cells, together forms…. Tissues!

A tissue is an ensemble of similar cells from the same origin that together carry out a specific function. Together, tissues forms an…. Organ!

An organ or viscus is a collection of tissues joined in a structural unit to serve a common function. Just like the cells and tissues, organs works together to form an… Organ System!

An organ system is a group of organs that work together to perform one or more functions. And finally, organ systems works together to form an… ORGANISM!

An organism is any living thing, an individual animal, plant, or single-celled life form!

What are Cells?Cells is the building blocks of life. It is the smallest structural and

functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane. Microscopic organisms typically consist of a single cell, which is

either prokaryotic or eukaryotic.

Cell is discovered by Robert Hooke, in 1665, who named the biological unit for its resemblance to cells inhabited by Christian

Monks in a monastery.

Cell theory, first developed in 1839 by Mathias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of

one or more cells.

Now that you know what are cells…

What are the

TYPES OF CELLSThe types of cells are Prokaryotes AND Eukaryotes or called

Prokaryotic cells and Eukaryotic cells.

Prokaryotic Cells or Prokaryotes

They are cells with the absence of nucleus, They have genetic materials but are not enclosed within a membrane. The genetic

material is a single circular DNA and is contained in the cytoplasm, since there is no nucleus. Recombination happens through

transfers of plasmids (short circles of DNA that pass from one bacterium to another). They do not engulf solids nor do they have

centrioles or asters.

A Picture of A Prokaryotic Cell

Eukaryotic Cells or Eukaryotes

These are cells with a nucleus, this is where the genetic material is surrounded by a membrane much like the cells membrane. Eucaryotic cells are found in humans and other multicellular

organisms (plants and animals) also algae, protazoa. They have both a cellular membrane and a nuclear membrane, also the

genetic material forms multiple chromosomes, that is linear and complexed with proteins that help it 'pack' and is involved in

regulation.

Eukaryotes are composed of both plant and animal cells. Plants vary from animal cells in that they have large vacuoles, cell wall,

chloroplasts, and a lack of lysosomes, centrioles, pseudopods, and flagella or cilia. Animal cells do not have the chloroplasts, and may

or may not have cilia, pseudopods or flagella, depending on the type of cell.

A Picture of A Eukaryotic Cell

A Venn Diagram That Shows the Difference And Similarities Between Prokaryotic And Eukaryotic Cells

Okay, so you are not yet familiarize with some words above right? But you will be in the next topic.

WHAT MAKES UP A CELL?

Every single cell are made up of ORGANELLES

WHAT IS AN ORGANELLE?

In biology, an organelle is a specialized sub-unit within the cell that has a specific function.

So.. what are organelles that makes up the cells?

Before that, there are three major parts that the cells have.

It is the

NUCLEUS, PLASMA MEMBRANE OR CELL MEMBRANE AND THE CYTOPLASM

So, those parts are also organelles.

ORGANELLES OF A CELL

Legend:

Blue = Function

Black = Description

1. Nucleolus

It is the largest structure in the nucleus of eukaryotic cells. It primarily serves as the site of ribosome synthesis and assembly.

2. Nucleus

It is a membrane-enclosed organelle found in eukaryotic cells. It control gene expression and mediate the replication of deoxyribonucleic acid or DNA during the cell cycle.

3. Ribosome

It is a large and complex molecular machine, found within all living cells. Ribosome is the workplaces of protein biosynthesis, the process of translating messenger ribonucleic acid (mRNA) into protein.

4. Vesicle

It is a small structure within a cell, consisting of fluid enclosed by a lipid bi-layer membrane. They can have a completely self-contained environment that is different from the inside of a cell.

5. Rough Endoplasmic Reticulum (RER or Rough ER)

It is studded with manufacturing ribosomes giving it a rough appearance. It serves as a site for protein and lipid synthesis.

6. Smooth Endoplasmic Reticulum (SER or Smooth ER)

It has functions in several metabolic processes. It synthesizes lipids and phospholipids, and steroids.

7. Golgi Apparatus (Golgi Body)

It is an organelle found in most eukaryotic cells. Identified in 1897 by the Italian physician Camilio Golgi and named after him in 1898. It packages proteins into membrane-bound vesicles inside the cell before the vesicles are sent to their destination.

8. Cytoskeleton

It is a intracellular matrix that supports cell shape and function, composed of actin filaments, microtubes, and nuclei. It provides the cell with structure and shape.

9. Mitochondrion

It is a double-membrane bound organelle found in most eukaryotic cells. It produces energy currency of the cell, adenosine triphosphate (ATP) trough respiration, and to regulate cellular metabolism.

10. Vacuole

It is a membrane-bound organelle which is present in all plant and fungal cells and some protest, animals, and bacterial cells. They contain waste products, containing water in plant cells and exports unwanted substances from the cell.

11. Cytosol [Intracellular Fluid (ICF) or cytoplasmic matrix]

It is the liquid found inside cells, it is separated into compartment by membranes. It transports metabolites from their site of production to where they are used.

12. Lysosome

It is a membrane bound cell organelle found in most animal cells. They break down waste materials and cellular debris. It is also called the STOMACH of the cell.

13. Centrosome

It is an organelle that serves as the main microtubule organizing center (MTOC) of the animal cell as well as a regulator of cell cycle progression. Centrosomes are associated with the nuclear membrane during prophases of a cell cycle. In mitosis, the nuclear membrane breaks down and the centrosome nucleated microtubules can interact with chromosomes to build the mitotic spindle.

14. Cell Membrane (Plasma Membrane or Cytoplasmic Membrane)

It is a biological membrane that separates the interior of the cells from the outside environment. The cell membrane surrounds the

cytoplasm of living cells, physically separating the intracellular components from the extracellular environment.

On memorizing the organelles of the cell, try repetition of words, or visualizing the words in your memory. The most effective method that I use in the mnemonic method, in which I use a “joke about the word” or “sounds like the word” and then I draw, then visualize it in my memory. For example, in chemistry, GOLD is one of the elements in the periodic table of elements and AU is its symbol. In order to memorize it, I make a sentence: “AU! U stole my GOLD!” then I searched on google a person running, stoling a gold, or if you don’t want to use google, just visualize someone or yourself stoling a gold, or you are shouting that certain sentence.

At the second part, we are going to talk about the cell cycle and how the cell works.

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