macromolecules 2

aldose

carbohydrate with aldehyde group

ketose

carbohydrate with ketone group

D-sugars and L-sugars

• mirror images

• D sugar = OH of 2nd carbon on the right

• L sugar = OH of 2nd carbon on the left

list 4 monosaccharides

• glucose

• fructose

• ribose

• glyceraldehyde

ring formation (aldose vs ketose)

• the OH group on the second to last carbon reacts with the aldehyde group/ketone group

alpha and beta monosaccharide forms

• alpha = OH on carbon 1 (ring formation) below the glucose ring (opposite CH2OH)

• beta = OH on carbon 1 (ring formation) above the glucose ring (same side as CH2OH)

formation of polysaccharides

• condensation reaction

• enzymes catalyse the formation of a covalent bond between monosaccharides (or subunits)

• formation of water molecule

breakdown of polysaccharides

• hydrolysis reaction

• enzymes catalyse the breakdown of a covalent bond between monosaccharides

• requires energy and water

linking two monosaccharides freezes the (?) form

alpha or beta

glycosidic linkage

• formed by the linkage of two monosaccharide units (via a condensation reaction)

• carbon-oxygen-carbon linkage

• name the two monosaccharide subunits

• disaccharide formation

• a1-D-glucoses

• between the OH on carbon one of the first D-glucose and the OH on carbon 4 of the second D-glucose

• what do the following beta linkages look like?

1. b1 - 6

2. b1 - 4

3. b1 - b1

4. b1 - a1

• what do the following alpha linkages look like?

• a1 - a1

• a1 - 2

• a1 - 6

cellulose

• polysaccharide

• structural function: forms cell walls of plants

• b1 - 4 linked D-glucose units

glycogen and starch

• polysaccharides

• glycogen: glucose (energy) store in animal cells

• starch: glucose (energy) store in plant cells

• glycogen and starch have similar structure

fatty acids are amphipathic

• hydrophilic polar head

• hydrophobic tail

unsaturated fatty acids

• double bond(s) in hydrophobic tail

• kinks formed

• do not allow close packing

• liquid at room temperature

saturated fatty acids

• no double bonds in hydrophobic tail

• tight packing

• solid at room temperature

triacylglycerides

• formed by condensation reaction between glycerol and three fatty acids

• triacylglycerides are not amphipathic

• saturated and unsaturated fatty acids determine structure and packaging of triacylglycerides

name three lipids that make up cell membranes

• phospholipids: OH in glycerol reacts with phosphate group

• glycolipids: OH in glycerol reacts with sugar group

• cholesterol: creates rigid regions in membranes

DNA vs RNA function

• DNA: long-term storage of hereditary material

• RNA: transient carrier of information

nucleotide composition

• nitrogenous base

• 5 carbon sugar

• phosphate group

ribose vs deoxyribose

deoxyribose lacks an OH on the second carbon

purines

• adenine

• guanine

pyrimidines

• cytosine

• thymine

• uracil

synthesis of sugar phosphate backbone

• nucleotides are joined together via phosphodiester bonds

• link the OH group on 3’ carbon of one sugar covalently to the phosphate group on the 5’ carbon of the next sugar

• condensation reaction

synthesis occurs in what direction?

5’ to 3’

how many hydrogen bonds between each complementary bases?

G pairs with C (3 H bonds)

A pairs with T (2 H bonds)

nucleotide function (list 3)

1. carriers of chemical energy

• high energy conserved in the phosphodiester bond

• cleavage releases energy used by cells

2. signaling molecules

• activate enzymes and turns on genes

3. combined with other groups as co-enzymes

amino acid composition (list 4)

• alpha carbon

• carboxylic acid

• amino group

• side chain group

amino acid chain synthesis

• condensation reaction forming peptide bonds

• OH of carboxylic acid group reacts with H of amino acid group

• water is formed

protein synthesis occurs in what direction?

from the amino (N-) terminal end towards the carboxylic (C-) terminal end