http://static. howstuffworks. com/gif/adam/images/en/proteins-picture http://static.howstuffworks.com/gif/adam/images/en/proteins-picture.jpg

Proteins Video

Proteins have a wide variety of uses: Structure (collagen) Muscle contraction (muscle fiber structures) Transportation (hemoglobin- carries O2) Immunity (antibodies) Carrying out chemical reactions (insulin, enzymes… more to come!)

Proteins contain these elements Carbon Hydrogen Oxygen Nitrogen And Sometimes Sulfur

Proteins have monomers too… Carbohydrates are made of monosaccharides Nucleic Acids are made of nucleotides Proteins are made of Amino Acids

Amino Acids There are 20 amino acids. Each amino acid is unique, just like the letters in the alphabet are unique. The order of amino acids in the proteins determines what that protein will do.

The “R” group is what makes each Amino Acid unique! http://www.hcc.mnscu.edu/chem/V.27/amino_acid_structure_2.jpg The “R” group is what makes each Amino Acid unique!

Amino acids http://trc.ucdavis.edu/biosci10v/bis10v/week2/2webimages/ch5-amino-acids.jpg

Amino Acids are strung together using a chemical reaction known as a “condensation reaction” One amino acid loses a hydrogen The other amino acid loses a hydrogen and an oxygen 2 hydrogen + 1 oxygen = water (H2O)

Making proteins requires that you lose a water molecule! http://homepages.ius.edu/GKIRCHNE/peptide.jpg

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Amino Acids joined by peptide bonds form a polypeptide chain http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Peptide.gif

Amino Acids interact, and this determines the shape of the protein Amino Acids interact, and this determines the shape of the protein. This can vary greatly. Size varies, too, depending on the length of the amino acid chain! Size matters… and shape too…. With proteins

The shape of the protein allows the protein to perform certain functions. If the shape of the protein changes, the protein can no longer do its job.

Protein Structure Primary Structure: sequence of amino acids Secondary Structure: Coils or folds in the polypeptide chain Tertiary Structure: Results from interactions between the “R” groups Quaternary Structure: Overall structure resulting from a protein that is made up of 2 or more chains http://academic.brooklyn.cuny.edu/biology/bio4fv/page/prot_struct-4143.JPG

A very special type of protein…Enzymes: Are used to change how quickly a chemical reaction will happen This is why they are called “catalysts”

Enzymes fit with their “substrates” like a lock fits with a key.

Fun animations to watch! http://www.biotopics.co.uk/other/anenz.html http://www.biotopics.co.uk/other/andnat.html http://www.biotopics.co.uk/other/aninac.html

Enzymes work at different rates depending on pH temperature concentration of the substrate environmental factors

http://schools.moe.edu.sg/chijsjc/Biology/Enzyme/enzyme1.gif

Effect of pH on Enzyme activity http://www.phschool.com/science/biology_place/labbench/lab2/ph.html

Effect of pH on Enzyme activity http://www.phschool.com/science/biology_place/labbench/lab2/ph.html

http://www.agen.ufl.edu/~chyn/age2062/lect/lect_03/3_46.gif

Affect of Temperature on Enzyme Activity http://www.biotopics.co.uk/other/andnat.html http://www.biotopics.co.uk/other/aninac.html

Enzymes will work faster if there is more substrate to work on until…. There is so much substrate that there is not enough enzyme to work. And vice versa. More enzymes work faster until they run out of substrate.

http://www.rsc.org/education/teachers/learnnet/cfb/images/07D.jpg

Enzymes are recyclable! When an enzyme is done with one piece of substrate, it moves on to the next one… And the next one… And the next one. Until the job is done. Quitters are losers!

Go ahead. Quit. We’re done. Loser. I mean… don’t quit. We still have work to do.