carbohydrates serve a variety of functionsrebecca/153a/w11/lectures/153a_w11...carbohydrates serve a...
TRANSCRIPT
![Page 1: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/1.jpg)
Carbohydrates serve a variety of functions
Energy storage
and food
Structure and
support
Lubrication
Protection
Recognition
and signaling
Component of
nucleotides
starch
mucin (glycoprotein)
surface glycoproteins
cell wall peptidoglycan
chitin and cellulose
2-deoxyribose
![Page 2: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/2.jpg)
![Page 3: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/3.jpg)
As for polypeptides, torsion angles describe
the conformations of polysaccharides
![Page 4: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/4.jpg)
Certain conformations (values of φ and ψ)
are more energetically favored than others
Both the identity of the monosaccharide units and how (where) they are
linked will determine which conformations are preferred
![Page 5: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/5.jpg)
We will cover 4 groups of polysaccharides:
Polysaccharides
Glycoconjugates
Energy storage
glycogen, amylopectin
Structure & protection
Structure & protection Recognition & adhesion
cellulose, chitin
glycosaminoglycans
amylose
proteoglycans glycolipids
proteoglycans
glycoproteins
lipid
protein
pro
tein
peptidoglycan
peptides
![Page 6: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/6.jpg)
Energy storage polysaccharides of animals
and plants are α-linked polymers of glucose
Animals store glycogen, a branched
homopolysaccharide with α1→4 and α1→6 linkages
![Page 7: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/7.jpg)
Energy storage polysaccharides of animals
and plants are α-linked polymers of glucose
Animals store glycogen, a branched
homopolysaccharide with α1→4 and α1→6 linkages
![Page 8: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/8.jpg)
Energy storage polysaccharides of animals
and plants are α-linked polymers of glucose
Plants store starch, an aggregate of amylose (linear)
and amylopectin (branched)
![Page 9: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/9.jpg)
Animals and plants use α-linked glucose
polymers for energy storage
Plants store starch, an aggregate of amylose (linear)
and amylopectin (branched)
![Page 10: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/10.jpg)
Glycogen and starch adopt loose, hydrated,
helical structures that pack into granules
![Page 11: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/11.jpg)
Most structural polysaccharides are
unbranched, β-linked polymers
Cellulose, an unbranched glucose homopolymer,
provides support and rigidity to plant cell walls
![Page 12: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/12.jpg)
Most structural polysaccharides are
unbranched, β-linked polymers
Cellulose chains form intra- and intermolecular H-
bonds, stacking to form cohesive and rigid fibers
![Page 13: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/13.jpg)
Most structural polysaccharides are
unbranched, β-linked polymers
Chitin gives rigidity to crustacean and insect
exoskeletons and to the cell walls of fungi and algae
Linear homopolymer of GlcNAc; packing is similar to cellulose
![Page 14: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/14.jpg)
Most structural polysaccharides are
unbranched, β-linked polymers
Glycosaminoglycans act as shock absorbers and
lubricants in the extracellular spaces of tissues
![Page 15: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/15.jpg)
Most structural polysaccharides are
unbranched, β-linked polymers
Abundance of negative charge keeps glycosamino-
glycan chains extended, separated, and hydrated
![Page 16: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/16.jpg)
Glycoconjugates have polysaccharides
covalently bonded to other molecule types
Peptidoglycan, composed of polysaccharides linked by
peptides, comprises the bacterial cell wall
![Page 17: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/17.jpg)
S. aureus
peptidoglycanGlcNAc Mur2Ac
![Page 18: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/18.jpg)
![Page 19: Carbohydrates serve a variety of functionsrebecca/153A/W11/Lectures/153A_W11...Carbohydrates serve a variety of functions Energy storage and food Structure and support Lubrication](https://reader034.vdocuments.mx/reader034/viewer/2022043017/5f39c49f02c67d730e52b258/html5/thumbnails/19.jpg)
Proteoglycans are conjugates of
proteins and glycosaminoglycans
Proteoglycans are major components of
connective tissue