Transcript Proteins
PROTEINS The final product of the DNA blueprint Hemoglobin Why are proteins important? “When the body has something it needs to do, it is a protein that does it” http://www.rothamsted.ac.uk/notebook/courses/guide/prot.htm Antibodies – fight disease Why are proteins important? “When the body has something it needs to do, it is a protein that does it” http://www.rothamsted.ac.uk/notebook/courses/guide/prot.htm Receptors – part of cell membrane, interacts with outside of cell and tells cell what’s happening Why are proteins important? “When the body has something it needs to do, it is a protein that does it” http://www.rothamsted.ac.uk/notebook/courses/guide/prot.htm Enzyme that digests insulin Enzymes – assemble or digest Why are proteins important? “When the body has something it needs to do, it is a protein that does it” http://www.rothamsted.ac.uk/notebook/courses/guide/prot.htm Neurotransmitters Neurotransmitters and hormones – bind to receptors to trigger a response Why are proteins important? Channels and pores – allow large molecules to pass through cell membranes What determines the role or function of a protein? Shape – click for examples What determines the shape of a protein? Amino acids are building blocks of proteins Amino Group Acid Group What determines the shape of a protein? B. 20 different amino acids each with their own R group Each “R” group gives amino acids their . . . - size - shape - charge - Preference for water (hydrophobic or hydrophilic) What determines the shape of a protein? Amino acids are connected by peptide bonds Four levels of structure (Just FYI) Primary Structure – Sequence of amino acids. Four levels of structure Secondary Structure – some chains form an alpha helix (coil) or a beta sheet (accordion). Four levels of structure Tertiary Structure – How all of the helices and sheets fold together. Four levels of structure Quaternary Structure – some proteins are made of more than one subunit. Summary – How the protein folds is determined by the type and number of amino acids used. How does the body know how to make proteins? A. DNA sequence. B. If nucleotide order is changed: - sequence of amino acids is changed. - Shape of protein is different. - Protein loses function. Cystic Fibrosis Video – “Cracking the Code” Chapter 9 ) Genetic Testing Video CLICK HERE http://topics.nytimes.com/top/news/national/series/dnaag e/index.html - WATCH “When a DNA Test Shows a Lethal Fate”