Upload
andrew-donaire
View
214
Download
0
Embed Size (px)
Citation preview
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 1/14
Schedule Activity
Feb 21 *Lecture (Protein Structure & Function Part 1 of 3)
*Short Exercise
Feb 26 *Pass assignment
*Quiz 1
*Lecture (Protein Structure & Function Part 2 of 3)
Feb 28 *Pass assignment
*Quiz 2
*Lecture (Protein Structure & Function Part 3 of 3)
Mar5 *Pass assignment*Quiz 3
*Lecture (Enzyme Part 1 of 2)
Mar 7 *Pass assignment
*Quiz 4
*Lecture (Enzyme Part 2 of 2)
Mar 11 *Pass assignment
*Quiz 5
*Lecture (Nucleotide, DNA, RNA)
Mar15 *Checking and Recording
*Review of topics for Final Exam
Mar 21 Final Exam
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 2/14
PROTEINE STRUCTURE
&
FUNCTION Part 1 of 3
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 3/14
Protein
Proteins are large biological molecules consisting of one
or more chains of amino acids. Derived from a greek word that means “of first importance”.
Provides an organism not only with C & H, but with N & S.
Most abundant macromolecule of the cell.
Carry most of the work of the cell.
Protects the body from infection, mechanical support and
strength, & catalysis of metabolic reactions - all are functions
of proteins that are essential to life.
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 4/14
Cellular Functions of Proteins
1. Enzymes are biological catalysts. Majority of the enzymes that
have been studied are proteins.
2. Defense protein include antibodies which are specific protein
molecules produced by specialized cells of the immune
system in response to foreign antigens.3. Transport proteins carry materials from one place to another.
4. Regulatory proteins control many aspects of cell function,
including metabolism and reproduction.
5. Structural proteins provide mechanical support to large animals
and provide them with outer covering.
6. Movement proteins are necessary for all forms of movement.
7. Nutrient proteins serve as sources of amino acids for embryos
or infants.
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 5/14
Structure of Amino Acids
Proteins of the body are made up of some combination of 20
different subunits called α-amino acids.
Orientation of almost all of the α-amino acids isolated proteins
in nature are members of the L-family.
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 6/14
Classes of Amino Acids
Class 1: Hydrophobic amino acids (9 amino acids)
glycine, alanine, valine, leucine, isoleucine, phenylalanine, proline,
tryphtophan, methionine
Class 2: Polar, neutral amino acids (6 amino acids)
serine, threonine, tyrosine, cysteine, asparagine, glutamineClass 3: Negatively charged amino acids (2 amino acids)
aspartate, glutamate
Class 4: Positively charged amino acids (3 amino acids)
lysine, arginine, histidine
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 7/14
Classes of Amino Acids
Class 1: Hydrophobic amino acids
Glycine (Gly) Alanine (Ala) Valine (Val) Leucine (Leu) Isoleuc
Phenylalanine (Phe) Proline (Pro) Tryptohan (Trp) Methionine (Met
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 8/14
Classes of Amino Acids
Class 2: Polar, neutral amino acids
Serine (Ser) Threonine (Thr) Tyrosine (Tyr) Cysteine (Cys) Asparagine (Asn) Glutami
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 9/14
Class 3: Negatively charged amino acids
Aspartate (Asp) Glutamate
(Glu)
Classes of Amino Acids
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 10/14
Classes of Amino Acids
Class 4: Positively charged amino acids
Lysine (Lys) Arginine (Arg)
Histidine (His)
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 11/14
Peptide Bond
Consider the dehydration reaction of glycine and alanine:
Peptide bond is an amide bond formed between the – COO-
group of amino acid and the α-N+H3 group of another amino
acid.
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 12/14
Peptide Bond
N-terminal
amino acid
(Glycine)
C-terminal
amino acid
(Alanine)
Peptides are named as derivatives of the C-terminal amino acid,
which
receives its entire name. For all other amino acids, the ending – ineis
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 13/14
Steps in writing the structure of a peptide chain:
1) Write the backbone for a tripeptide.
2) Add oxygens to the carboxyl carbons and hydrogens to the
amino nitrogens
3) Add hydrogens to the α-carbons:4) Add the side chains.
Short Exercise: (Short yellow pad)
Write the structure of each of the following peptide:
1) lysyl-alanine
2) alanyl-glycyl-valine
3) phenylalanyl-tyrosyl-leucine
Peptide Bond
7/28/2019 Protein 1 of 3 - Students Copy
http://slidepdf.com/reader/full/protein-1-of-3-students-copy 14/14
Assignment
Research about α-helix and β-pleated sheet.
Include figures and diagrams.