BIOCHEM WEEK 2

monosaccharides

simplest sugars

polysaccharide

linked monosaccharides

glycosidic bond

joins a carbohydrate molecule to another group

glycoside

sugar molecule bound to something else via a glycoside bond

sucrose

glucose + fructose =

sucrase

the enzyme that breaks down sucrose into glucose & fructose

lactose

glucose + galactose=

lactase

the enzyme that breaks down lactose into glucose & galactose

glycogen

polysaccharide of stored sugar

salivary-amylase

in saliva, hydrolyzes starch to glucose

breaks alpha-1,4-glycosidic bonds

glycogenolysis

breakdown of glycogen —> glucose

uses enzyme glycogen phosphorylase (PG)

works on alpha-1,4-glycosidic bonds

glucagon

promotes glycogenolysis

glycoproteins

more protein than sugar

proteoglycans

more sugar than protein

lectin

proteins that bind to specific carbohydrate

carbohydrate recognition domain

specific region within a protein that recognizes and binds to carbohydrates

selectins

subtype of lectins, involved in wound healing

glycosyltransferases

enzymes that form glycosidic bonds between sugar molecules and other molecule, resulting in a glycoside

glycation

sugars spontaneously bind to proteins or lipids without the involvement of enzymes

Leads to advanced glycation end products (AGE)

dextran

a type of carbohydrate

bacteria produce dextran using the enzyme dextransucrase

glycocalyx

sticky, extracellular polysaccharide layers

sticks to teeth surfaces

first step in carious lesions

blood types

determined by glycosyltransferases

A, B, AB, O

blood type A

produces antibodies against Type B antigens

Donates to A/AB, receives from A/O

blood type B

produces antibodies against Type A antigens

Donates to B/AB, receives from B/O

blood type AB

has no antibodies

Donates to AB, receives from A/B/AB/O

blood type O

has antibodies against Types A and B

Donates to A/B/AB/O, receives from O

lipids

biomolecule that is hydrophobic and nonpolar

fatty acids

hydrocarbons that terminate with carboxylic acid groups

amphipathic

unsatured fatty acids

double bonds present

cis bend in chain

less dense, liquid at room T

saturated fatty acids

no double bonds

more dense

solid at room T

trans-unsaturated fatty acids

has double bond, but in trans configuration

triglyceride

3 FA and glycerol backbone

adipose tissue/fat

lipase

cleaves FA from glycerol

phospholipid

glycerol backbone, 2 FA, phosphate

referred to as lecithin

referred to as lecithin

phosphatidylcholine

most abundant phospholipid

contains choline

involved in transport

sphingolipid

built on sphingosine backbone instead of glycerol

ceramide

sphingosine backbone, 1 FA, attached to single H

sphingomyelin

sphingosine backbone, 1 FA, attached to a choline— used in nervous system

glycolipid

sphingosine backbone, 1 FA, attached to a sugar group

termed ganglioside when it’s an oligosaccharide attached instead of a simple sugar group

steroid

made up of a tetracyclic ring called steroid nucleus

involved in hormones and cell membranes

hydrophobic

cholesterol

the most abundant steroid

lipid digestion enzymes

lingual lipase in mouth

gastric lipase in stomach

pancreatic lipase in small intestine