About My Project

Introduction:

  • What is the basic structure of a protein and how are they produced in cells? What functions do proteins play?

Materials:

  • Protein Synthesis Kit

  • Camera

Procedures:

Pre-Lab Preparating

  1. Obtain 20 round amino acid chips, 20 round labels, and a marker.

  2. Using the chart below as a guide, write the three letter code for each amino acid on the 20 round labels.

  3. Center and place the labels on the amino acid round chips.

  1. Obtain a Ribosome Master Sheet, an mRNA strand, a tRNA set (20 cards) and the 20 labeled amino acid chips from before.

  1. Activate each amino acid chip by attaching it to the specific tRNA molecules using double sided tape.

    1. Locate the methionine (met) amino acid assembled in step 2. Place the methionine amino acid on the peptidyl binding site on the ribosome master sheet.

    1. Obtain a mRNA strand. Place the mRNA strand on the mRNA site of the ribosome. The mRNA strand should read from 5' to 3' from left to right.

    1. Match up the complementary amino acid to this mRNA codon.

    1. Place a piece of transparent tape from the methionine amino acid to the new amino acid on the aminoacyl tRNA binding site to represent this bond.

    1. Move the ribosome to the right one codon so that the amino acid tRNA complex that was on the aminoacyl tRNA binding site will now be on the peptidyl tRNA binding site.

    1. Because the mRNA codon on the new aminoacyl binding site requires a new amino acid tRNA complex, find the complementary amino acid and place it on the aminoacyl site.

    1. Place another small piece of tape between the new amino acid on the aminoacyl binding site and the amino acid on the peptidyl tRNA binding site.

    1. Move the ribosome to the right once again until the aminoacyl binding site is once again open.

    1. As the amino acid move off the ribosome, they break apart. The first amino acid, methionine, will remain attached to the second amino acid forming a protein chain. the tRNA molecule that has broken away from the amin oacid enters the cytoplasm in search of another amino acid.

    1. Repeat steps 5-11 of the remaining mRNA codon until the entire mRNA strand is completely translated.

Scientific Principle(s):

  • A scientific principle of protein structure is that protein models represent protein chains, involving a bit of approximations and allow complete sequence spaces. The folding code is mainly binary and delocalized throughout the amino acid sequence (Abe H, Go N). Another scientific principle about protein translocation across membranes is that most major transport protein systems across a membrane share these certain features: amino-terminal transient signal sequence, a targeting system of the membrane, hetero-oligomeric transmembrane channel which is gated across and within the plane of the membrane, peripherally attached protein translocation motor powered by hydrolysis, a protein folding system on the trans side of the membrane.

Safety Regulations:

No safety regulations necessary.

INVESTIGATION QUESTIONS (Task 6)

    1. What protein is the main component of Jell-O's jiggly structure?

      1. Collagen is the main protein component of Jell-O’s jiggly structure.

    2. Describe the basic structure of collagen and its function.

      1. Collagen is a major insoluble protein in the connective tissue and in the extracellular matrix. It’s basic structure is a triple-stranded helical molecule, from three different amino acids: glycine, proline, and hydroxyproline. Each triple-stranded collagen molecule is 300 nm (Nautical Mile) long and 1.5-nm-diameter thin. The collagen molecules are packed together side by side.

      2. Some functions of collagen include giving cell structures from the outside and serving as the main component of body parts like cartilage, ligaments, tendons, bones, and teeth. Collagen and soft keratin work together to make the skin have elasticity and strength. Collagen also strengthens blood vessels and plays a large role in producing tissues.

    1. Pineapple contains a protein called bromelin. What does this protein do? How does this help explain the results of the experiment?

      1. Bromelin is mostly used in the medical department. For example, it’s used for reduction in swelling or inflammation mostly in sinuses. Bromelin also can treat indigestion. I have not done the experiment yet due to unavailable materials, so the results currently are unknown.

    1. Collagen (gelatin) and bromelin are both proteins. In what ways are all proteins similar?

      1. Nearly all proteins have the same empirical formula: C400H620N100O120P1S1.

      2. All proteins have functions.

      3. All proteins are needed in organisms.

    1. If all proteins are made up of the same basic subunits, how can proteins have such different shapes and functions?

      1. Proteins can have such different shapes and functions because it all depends on the amino acid sequence. Not all of the sequences are the same.

    1. Research and describe at least three different functions proteins have in cells and organisms.

      1. Because most enzymes are proteins, enzymes increase the speed of chemical reactions.

      2. Proteins can serve as transport molecules. Hemoglobin transports oxygen.

      3. Proteins are a definite necessity to most organisms’ body: in order for movement to occur (i.e. walking, blinking, talking), proteins in cells create muscles and organs.

    1. What determines the shape (the 3-D structure) of a protein?

      1. The amino acid sequence of a protein determines the shape of a protein.

    1. The information for making each protein in a cell is encoded within DNA (genes). Create a graphic organizer to illustrate the steps involved in protein synthesis (going from DNA to protein). Include the following in your organizer: DNA, ribosome, nucleus, tRNA, mRNA, amino acids.

Investigation