Taking a Closer Look: Cells

Did you know that an ostrich egg can weigh up to 3 pounds, and its yolk is the largest cell on earth? A typical ostrich egg is equivalent in size to 24 chicken eggs, being 10 inches high and 6 inches in diameter.

Although most cells are so small we cannot see them some, usually eggs, are big enough to see without a microscope and even touch. Dwarfed by these jumbo cells, the common cell is typically about 15 micrometers. 1000 micrometers are equivalent to one millimeter. We will be taking a look inside these tiny cells and looking at their tiny organelles which are actually quite similar to the organs we have but a whole lot smaller.

Only plant cells have cell walls. They are rigid, strong, and made of cellulose. 

The cell membrane keeps things in the cell or out of the cell depending on what it is. In an animal it is the outermost part, but in a plant cell it is located inside of the cell wall.  

The nucleus is located in the center of a cell, contains DNA, and controls the activities of the cell. You can think of it like our brain as both carry out similar functions.  

Red blood cells are the only eukaryotic cells without a nucleus. They cannot reproduce so they are produced in your bone marrow from stem cells. It is red blood cells that make your blood red.

Image via Wikipedia

Cytoplasm is the clear jelly like fluid that fills the cell. It supports the cell and its main purpose is to cushion and protect the other organelles.

The Endoplasmic Reticulum (ER) is a network of tubes that transports materials throughout the cell. ER with ribosomes on it are ‘rough’ while those without ribosomes are ‘smooth’. Ribosomes can be free-floating or attached to ER and their role is to produce proteins.

The mitochondria break down food to be used as energy.

The Vacuole is a fluid filled sac that stores water, food, and waste. Animal cells have several small ones while plant cells have one large one.

The Lysosome breaks down large food particles into small ones and digests old cell parts. It is more common in animal cells but also can be found in plant cells

The chloroplast is only found in plant cells and contains chlorophyll so the plant can use light to make food which is the process known as photosynthesis.