IPAP Biochem Chapter 2 - Carbohydrates

Carbohydrates

Have a formula of (CH2O)x, where x = a number from 3-7

Triose

Three carbon monosaccharide

Tetrose

Four carbon monosaccharide

Pentose

Five carbon monosaccharide

Hexose

Six carbon monosaccharide

Heptose

Seven carbon monosaccharide

Carbohydrate suffix

-ose

Common monosaccharides in human biology

Glyceraldehyde, ribose, glucose, fructose, galactose

Hexose monosaccharides

Glucose, Galactose, and Fructose

Pentose monosaccharide

Ribose

Triose monosaccharide

Glyceraldehyde

Which carbons of monosaccharides are especially reactive?

First and sixth carbons

What part of monosaccharides are hydrophilic and reactive?

The hydroxyl groups

Common diasaccharides in human biology

Lactose, trehelose, maltose, and sucrose

Lactose

Formed from galactose and glucose

Where do glucose and galactose form a glycosidic bond to form lactose?

Carbons 1 & 4

Trehelose

Formed from two glucoses

Where do two glucose molecules bond to form trehelose?

Carbons 1 & 1

Maltose

Formed from two glucoses

WHere do two glucose molecules bond to form maltose?

Carbons 1 & 4

Sucrose

Formed from glucose and fructose

Where do glucose and fructose bond to form sucrose?

Carbons 1 & 2

Glycogen

formed from glucose molecules bound together linearly

What is glycogen used for?

Carbohydrate storage

Where are the glucose molecules in glycogen bonded linearly?

Carbons 1 &4

Glycogen branches approximately every how many glucose molecules?

10

Where are the bonds that form the branches in glycogen?

Carbons 1 & 6

How many molecules of glucose long is glycogen typically?

Thousands

Glycoproteins

Formed from a bond between a carbohydrate and a serine, threonine, or asparagine

Where does a carbohydrate bond to a serine or threonine to form a glycoprotein?

Between the carbohydrate hydroxyl group and the amino acid hydroxyl group

Where does a carbohydrate bond to a asparagine to form a glycoprotein?

Between the carbohydrate hydroxyl group and the amine nitrogen of the amino acid

How many proteins in the body are glycoproteins?

Approximately half

Examples of functional roles glycoproteins play in the human body

Binding, signaling, and regulation

Glycosaminoglycans (GAGs)

Contain repeating disaccaharide chains of modified glucose and/or galactose

What are the modifications of the glucose and galactose in a GAG?

Amine group added with an acetyl (NHCOCH3) or a negatively charged sulfate (NHSO3-)

In a GAG, the negatively charged sulfate is linked to what?

The hydroxyl or carboxyl of at least one disaccharide in the repeating chain

Common GAGs

Heparin, chondroitin, and hyaluronic acid

Which GAG is the longest?

Hyaluronic acid

What function is heparin involved in?

Clot regulation

What structures is chondroitin involved with?

Connective tissue and cartilage

Proteoglycans

Formed by a bond between a GAG and a protein

What are proteoglycans important for?

Strong structural elements in connective tissue, collagen