Unit I Lab Project - Build a Cell

Prior to demonstrating mitosis and revealing the cell model, I will attempt to demonstrate the transcription of DNA to mRNA and mRNA translation to proteins.

The DNA strand opens.

The RNA polymerase to transcribes a single strand of DNA into a single stranded RNA polymer called messenger RNA (mRNA).

After the RNA is completed (now mRNA), the DNA strand closes.

A small ribosomal subunit attaches to the RNA. Note the codons on the RNA (zipper teeth). These dictate which amino acids will be aligned for the protien to be processed.

tRNA has specific anticodons that will align only with a certain combination of codons in the RNA strand. These will attach to the mRNA in the order dictated. Attached to the end of the tRNA is an amino acid (pearl). A large ribosome will then cover this activity, and will not be demonstrated.

A second tRNA will attach to the mRNA with its accompanying amino acid. The previous amino acid will attach to the new arrival.

The first tRNA will then dislodge from the mRNA leaving its amino acid attached to the second one.

The process keeps repeating itself. . .

Each tRNA will leave after the arrival of the next one, forming a chain

of amino acids.

This is the completed protein.

Now for mitosis. Mitosis is the process through which cells replicate.

During the interphase (beginning of the cell cycle) chromosomes will replicate and form chromatids to prepare for cell division. Chromatids are DNA that has been reproduced and has both strands joined together in the center. Looks like a floating X. Now for the picture that's worth a thousand words. . .

Not enough detail in this cell, you say? Well, you haven't seen it all.

The family has been eagerly awaiting the creation of the jello cell. This cell will represent the following:

Cell Membrane: Glass bowl

This protects the cell. Regulates the transport of matter in an out of the cell. Regulates receptivity and signalling through receptors in membrane. Identifies the cell to others. Cytoskeletal filaments anchor to membrane wall and helps to hold it's shape.

Nucleus with nuclear membrane: Boiled egg

The nucleus is a membrane bound structure that contains the cell's hereditary information and controls the cell's growth and reproduction. It is commonly the most prominent organelle in the cell. (http://biology.about.com/library/weekly/aa032300a.htm)

Endoplastic Reticulum (ER):

Rough with ribosomes: striated fruit tape

Rough (ER) is covered with ribosomes and produces proteins.

Smooth without ribosomes: blue fruit tape

Smooth ER transports material through the cell. It has

enzymes that help produce and digest lipids and proteins.

Golgi apparatus: licorice

It produces vesicles which contain proteins and carbohydrates for export from the cell.

Mitochondria: Pecan

It has a double membrane. Converts glucose into ATP, the usuable energy for the cell.

Cilia or flagella: Sprouts glued to bowl

Small microtubules that form together to make "whips" that facilitate movement - either of the cell itself or of materials that need to be relocated.

Protein: Jelly bellies (thanks to my husband for his selfless sacrifice) in cell wall.

Protein molecules embedded in the cell membrane facilitate transport of substances in and out of the cell.

Cytoskeleton: Alfalfa sprouts inside the cytoplasm

Microtubules and filaments that provide support and help organelles move around inside the cell.

THE CELL!!

Here's some of the basic building blocks. The kids are now happily sugared from the remnants of this lab and gratefully, they found an outside activity . . . needless to say, they didn't go for the eggs,nuts or sprouts.

DNA replication is explained on the following website. http://video.google.com/videoplay?docid=-7158977581753243907&q=dna+replication&total=119&start=10&num=10&so=0&type=search&plindex=7

Hope you enjoyed this lab. I will say it's more interesting than typing a compendium.