BIOL 5 A

Cell

* The basic structural and functional unit of living organisms 


* Cells make up living things and carry out activities that keep a living thing alive. 

Unicellular Organisms

An organisms that is made up of one cell

Multicellular Organisms

An organisms that is made up of more than once cell

Smallest Cell

Mycoplasma

Largest cell

Ostrich Egg

sperm cell

The smallest cell in humans

Ovum or egg cell

Largest cell in the human

Nerve cell

Longest cell for human

Microscope

A laboratory instrument used to examine objects that are too small to be seen by the naked eye.

Plasma membrane

To maintain the shape and size of the cell, protect the internal contents of the cell, and regulate the entry and exit of substances in and out of the cell.

Cell wall

Provides definite shape, strength and rigidity, prevents trying ip of cells, and protects bacteria and plants from harmful pathogens.

Nucleus

Control center of the cell

Cytoplasm

* Present between the plasma membrane and the nucleus. 
* Contains a clear liquid portion called **cytosol** and **various particles.**

Endoplasmic reticulum

Provides internal support to the cytoplasm.

Rough and smooth endoplasmic reticulum

Types of Endoplasmic reticulum

Rough endoplasmic reticulum

Contains ribosome and its function is to synthesize proteins.

Smooth endoplasmic reticulum

Synthesizes lipids for the cell membrane. In the liver, it also detoxify drugs and poisons.

Golgi bodies

An organelles that function is modification, sorting, and packing of materials synthesized in the cell.

Lysosomes

Helps in digesting large molecules, protecting cell by destroying foreign invaders.

Vacuoles

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* The storage of various substances may have different roles depending on the type of organism. 

Mitochondria

* It is called the powerhouse because it functions in the synthesis of adenosine triphosphate (ATP) that provides the energy vital for the activities of the cell. 

Plastids

* Also called the double membrane-bound organelles. 

Chromoplasts

Found in fleshy fruits, and flowers as well as various other pigmented parts of the plant such as leaves. Plastids that act as the site of pigment accumulation.

Leucoplasts

Plastids that are non-pigmented. Specialized for bulk storage of scratch, lipid, or protein and are then known as amyloplasts, elaioplasts, or proteinoplasts.

Chloroplasts

* Plant cell organelles that convert light energy into relatively stable chemical energy via photosynthesis. 


* Als provides green color to leaves and stems.

Grana and Stroma

2 distinct regions of chloroplasts

Grana

Stacks of thylakoids. Thylakoids that contains chlorophyll which re responsible for light reactions of photosynthesis;

Stroma

Where the process of producing starch or sugar occurs.

Centrosome

An organelle present in animal cell that is involved in the process of cell division. Composed of two structure called centrioles (that are made up of microtubules).

Cytoskeleton

* System of filaments that is present in the cytoplasm of eukaryotic cells.
* Organizes other constituents of the cell, maintains the cell’s shape, and is responsible for the locomotion of the cell itself.  

Actin Filaments, Microtubules, and Intermediate filaments.

**3 major types of filaments;** 

Actin filaments

Occur in a cell in the form of bundles of parallel fibers. Help determine the shape of the cell and also help it adhere to the substrate. 

Microtubules

Longer filaments that are constantly assembling and disassembling. Play a crucial role during mitosis and form cilia and flagella.

Intermediate filaments

Are very stable structures that form the true skeleton of the cell.  

Prokaryotic Cell

Nucleus is absent

Only one chromosomes is present

Membrane bound organelles are absent

Size ranges from 0.5 -5 micrometer

Examples are Bacteria and Blue and Green Algae

Eukaryotic Cell

Nucleus is well developed

More than once chromosomes are present

Membrane bound organelles are present

Size ranges from 5-100 micrometer

Examples: All other organisms