Download presentation
Presentation is loading. Please wait.
Published byKelly Bell Modified over 9 years ago
1
LEVELS OF PROTEIN STRUCTURE A.Primary Structure—the unique sequence of amino acids, type sequence and number; determines the other three structures It is held together by peptide bonds between the carboxyl group of one amino acid with the amino group of another amino acid B. Secondary Structure― regular repeated coiling and folding of the polypeptide caused by H–bonds between atoms in the polypeptide backbone (a hydrogen on a nitrogen and a double–bonded oxygen atom) see Fig. 5.20 p. 76 a. alpha helix― a delicate coil held together by hydrogen bonding between every fourth peptide bond b. Beta pleated sheet― where regions of the chain lie parallel to each other
2
LEVELS OF PROTEIN STRUCTURE C. Tertiary Structure―the irregular contortions in the polypeptide chain caused by bonding between atoms in the side chains (R–groups) a. hydrogen bonds between atoms in R–groups b. hydrophobic interactions― the congregating of nonpolar R– groups in the core of the protein away from water c. hydrophilic interactions― the twisting of polar R–groups toward water d. ionic bonds between positively and negatively charged R– groups of some amino acids e. disulfide bridges― covalent bonds between two cysteine amino acids with sulfhydryl groups are brought close enough together by the folding of the protein D. Quaternary Structure― when two or more polypeptide chains are joined together by bonds or interactions of their R–groups. Same as a–e above.
3
THE STRUCTURE AND FUNCTION OF MACROMOLECULES
4
Linus Pauling determined the alpha helix structure of a protein
6
Alias-PGAL or G3P Ribulose as in biphosphate
7
1 2 3 4 5 6
8
1 2 34 5 6
13
curved chain that forms a coil curved chain that forms a coil with many branches
14
curved
17
It has more branches than amylopectin
21
All these can form H-bonds with other cellulose molecules
23
alpha-glucose beta-glucose starch cellulose
25
STARCHCELLULOSE 1. alpha glucose1. beta glucose 2. 1 4 bonds easily broken by vertebrate enzymes 2. 1 4 bonds only broken by the enzymes of a few bacteria protozoans and fungi 3. forms helix w/ OH's inside making it slightly soluble 3. forms straight molecule w/ OH's sticking out above and below 4. no H ‑ bonds between chains 4. forms H ‑ bonds between chains 5. energy storage5. structural uses
28
Chitin-structural polysaccharide found in arthropod exoskeletons and fungus cell walls Monomers of beta glucose with a nitrogen containing group on the #2 carbon
29
Chitin-structural polysaccharide found in arthropod exoskeletons and fungus cell walls
33
Triacylglycerol—stores twice as much energy per gram as carbohydrates; also used structurally as cushions around vital organs and insulation against heat loss
40
waxes
41
Glycolipid-a chain of sugars attached to the third carbon of a glycerol-- gives it a polar but not charged head; found in cell membranes; it has a polar but not charged head and two nonpolar tails so it sits a little deeper in the membrane; It is used for adhesion and identification by lymphocytes
44
PROTEINS POLYMERS OF AMINO ACIDS
45
PROTEINS POLYMERS OF AMINO ACIDS
46
cysteine alanine
47
Dipeptide
54
alpha helixbeta pleated sheet Hydrogen bonds Secondary structures
60
3 alpha helix into a quartenary
61
Microtubules-a fibrous or tubular protein composed of many globular dimers
64
LEVELS OF PROTEIN STRUCTURE A.Primary Structure—the unique sequence of amino acids, type sequence and number; determines the other three structures It is held together by peptide bonds between the carboxyl group of one amino acid with the amino group of another amino acid B. Secondary Structure― regular repeated coiling and folding of the polypeptide caused by H–bonds between atoms in the polypeptide backbone (a hydrogen on a nitrogen and a double–bonded oxygen atom) see Fig. 5.20 p. 76 a. alpha helix― a delicate coil held together by hydrogen bonding between every fourth peptide bond b. Beta pleated sheet― where regions of the chain lie parallel to each other
65
LEVELS OF PROTEIN STRUCTURE C. Tertiary Structure―the irregular contortions in the polypeptide chain caused by bonding between atoms in the side chains (R–groups) a. hydrogen bonds between atoms in R–groups b. hydrophobic interactions― the congregating of nonpolar R– groups in the core of the protein away from water c. hydrophilic interactions― the twisting of polar R–groups toward water d. ionic bonds between positively and negatively charged R– groups of some amino acids e. disulfide bridges― covalent bonds between two cysteine amino acids with sulfhydryl groups are brought close enough together by the folding of the protein D. Quaternary Structure― when two or more polypeptide chains are joined together by bonds or interactions of their R–groups. Same as a–e above.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.