CarbohydratesCarbohydrates

A Few QuestionsA Few Questions

1) What is the general term used for the 1) What is the general term used for the simplest carbohydrates?simplest carbohydrates?

2) What structural difference is found in 2) What structural difference is found in the straight chain forms of D-Glucose the straight chain forms of D-Glucose and D-Fructose?and D-Fructose?

3) What causes lactose intolerance?3) What causes lactose intolerance?

4) What are three differences between 4) What are three differences between glycogen and cellulose?glycogen and cellulose?

5) What are lectins and what are some 5) What are lectins and what are some processes they mediate?processes they mediate?

What are Carbohydrates?What are Carbohydrates?

Polyhydroxy aldehydes and ketonesPolyhydroxy aldehydes and ketonesusually have “ose” suffixusually have “ose” suffix

Simple sugarsSimple sugarsMonosaccharidesMonosaccharidesDisacccharidesDisacccharides

Complex carbohydratesComplex carbohydratesOligosaccharidesOligosaccharidesPolysaccharidesPolysaccharides

Functions of CarbohydratesFunctions of Carbohydrates

Stored chemical energy (oxidized to release Stored chemical energy (oxidized to release energy)energy)

Component of nucleotides Component of nucleotides nucleic acids – DNA and RNAnucleic acids – DNA and RNAcoenzymes – NADH, coenzyme A…….coenzymes – NADH, coenzyme A…….

Structural role (ie cell walls)Structural role (ie cell walls)

Linked to proteins and lipidsLinked to proteins and lipidscell surface recognition pointscell surface recognition points

MonosaccharidesMonosaccharides

Foundational building block of Foundational building block of carbohydratescarbohydrates

(C-H(C-H22O)O)nn n = 3-9 typicallyn = 3-9 typically““carbon hydrate”carbon hydrate”

Typically D enantiomer Typically D enantiomer What causes this? Why is it important?What causes this? Why is it important?

Straight chain form or cyclic form Straight chain form or cyclic form

Aldoses (trioses to hexoses)Aldoses (trioses to hexoses)

Ketoses (trioses to hexoses)Ketoses (trioses to hexoses)

Pyranose vs FuranosePyranose vs Furanose

6 membered ring6 membered ring

5 membered ring5 membered ring

Forms of D-GlucoseForms of D-Glucose

Forms of D-FructoseForms of D-Fructose

Cyclic form of D-RiboseCyclic form of D-Ribose

Glycosidic BondsGlycosidic Bonds

Sugar PhosphorylationSugar Phosphorylation

Traps them within the cell (anionic)Traps them within the cell (anionic) Makes them more reactiveMakes them more reactive

DisaccharidesDisaccharides

MaltoseMaltose

DisaccharidesDisaccharides

Lactose IntoleranceLactose Intolerance

What is it?What is it?

What causes it?What causes it?

How do we deal with it?How do we deal with it?

Polysaccharides - StarchPolysaccharides - Starch

Amylose (Amylose (-1,4)-1,4) Amylopectin (Amylopectin (-1,4 with -1,4 with -1,6 about every 30)-1,6 about every 30)

Polysaccharides - GlycogenPolysaccharides - Glycogen

((-1,4 with -1,4 with -1,6 about every 10)-1,6 about every 10)

Polysaccharides - CellulosePolysaccharides - Cellulose

((-1,4 linkages giving a very linear structure)-1,4 linkages giving a very linear structure) Dietary fiberDietary fiber

GlycoproteinsGlycoproteins

O-linked vs N-linkedO-linked vs N-linked

LectinsLectins

Mediate cell-cell interaction Mediate cell-cell interaction

(ie in development and wound healing)(ie in development and wound healing)

Lectins can mediate Lectins can mediate bacterial and viral infectionbacterial and viral infection

SelectinsSelectins

L – on lymphocytes and mediate binding to lymph L – on lymphocytes and mediate binding to lymph node vessels (also mediate embryonic implantation)node vessels (also mediate embryonic implantation)

E – on circulating cells binding to endotheliumE – on circulating cells binding to endothelium P – on activated blood plateletsP – on activated blood platelets