1. Organic Macromolecules: Carbohydrates
Biochemistry
Organic Macromolecules: Carbohydrates

2. Organic macromolecules: carbohydrates
Carbohydrates are organic compounds that contain carbon, hydrogen, and oxygen in a ratio of CnH2mOm
(Hydrogen:Oxygen ratio = 2:1)
There are three categories of carbohydrates: monosaccharide, disaccharide, and polysaccharide.

3. Organic macromolecules: carbohydrates
Monosaccharide – a simple sugar Disaccharide – two monosaccharides joined together through a dehydration synthesis Polysaccharide – a sugar macromolecule composed of many monosaccharides (polysaccharides are carbohydrates)

4. Organic macromolecules: carbohydrates
The most common monosaccharide is glucose
The chemical formula for glucose is C6H12O6
Glucose can be found as an aldose or ketose based on the carbon atom the carbonyl group is added to.

5. Organic macromolecules: carbohydrates
Glucose (aldose)
Fructose (ketose)

6. Organic macromolecules: Carbohydrates
Glucose can exist in two forms α glucose and β glucose

7. Organic macromolecules: carbohydrates
Disaccharides and Polysaccharides are formed when monosaccharides are joined together through a dehydration synthesis
A glycosidic bond (linkage) is formed when two monosaccharides are joined together.
Glycosidic bond (linkage) – the connection in a disaccharide or polysaccharide chain formed by the removal of water.

8. Organic macromolecules: carbohydrates

9. Organic macromolecules: carbohydrates
When two monosaccharides are joined together it is called a disaccharide
Different disaccharides are formed based on two variables:
The carbon atoms that are being joined between the monosaccharides
The types of monosaccharides being joined

10. Organic macromolecules: carbohydrates

11. Organic macromolecules: carbohydrates
Polysaccharides can be used for storage of energy and structure.
Starch is a polysaccharide in plants made entirely of α glucose monomers.
One type of starch is amylose and it is comprised of 1-4 linkages (number 1 carbon of one glucose molecule bonds to the number 4 carbon of the next glucose molecule)
The angle of this bond makes the polysaccharide helical

12. Organic macromolecules: carbohydrates
Another type of starch is amylopectin and it is comprised of mostly 1-4 linkages but it branches so it has 1-6 linkages at the branch
*amylose and amylopectin are sugars made by plants. Amylase is an enzyme found in human saliva and is made by the pancreas to break down these sugars in our food*

13. Organic macromolecules: carbohydrates

14. Organic macromolecules: carbohydrates
Glycogen is an energy storage molecule in animals made up of glucose monomers
Glycogen is similar to amylopectin, except that it contains numerous branches.
Most vertebrate animals store glycogen primarily in the liver and muscles.

15. Organic macromolecules: carbohydrates

16. Organic macromolecules: carbohydrates
Cellulose is another polysaccharide found in plants
Like starch, cellulose is made up glucose monomers but they are all in the β conformation so that every other glucose molecule in the polysaccharide is flipped.
This allows strands of cellulose to hydrogen bond with eachother and become very strong
The strength of cellulose gives the structure to plants and plant cells

17. Organic macromolecules: carbohydrates

18. Organic macromolecules: carbohydrates
Very few organisms have the enzymes to break down cellulose
Enzymes designed to break down starch do not break down cellulose
Cows have the enzymes needed to break down cellulose as do some microbes
Humans cannot break down cellulose but it helps in digestion and is still a necessary part of a healthy diet