Biologicalm moles

What ion is required for the hydrolysis of starch by an enzyme?

Chlorine (Cl-)

Pentose

5 carbons

Hexose

6 carbons

Describe ribose

ribose is a pentose monosaccharide found as a pentose sugar in DNA (deoxyribose sugar)

Describe cellulose

Beta glucose (alternating molecules must be inverted otherwise hydroxyl groups are too far to bond), straight chained molecule, make hydrogen bonds > microfibril > macrofibril > fibres

Cellulose fibres

strong, insoluble, used to make cell walls, good for digestion

Fructose

hexose monosaccharide, occurs naturally in fruit

Sucrose

disaccharide, alpha glucose and fructose monomers, alpha non-reducing sugar, found in sugar cane ect

Maltose

2 alpha glucose monomers

Lactose

galactose + glucose monomers

Elements in carbohydrates

C, H, O

Elements in lipids

C, H, O

Elements in protein

C, H, O, N, S

Elements in nucleic acids

C, H, O, N, P (ATP is also a nucleic acid)

Biuret test method and positive result and what it tests for

Tests for - proteinsMethod - add Biuret's solution to samplePositive result - lilac colour

Method -

Positive result -

Benedict's test method and positive result and what it tests for (reducing)

Tests for - reducing sugars

Method - place sample in boiling tube (if solid, grind it up or blend in water), add equal amount Benedict's solution

Positive result - brick red colour

Why does the test for reducing sugars work?

Benedict's solution contains Cu2+ ions [copper(II) sulfate] that are blue

reducing sugars react with the copper ions reducing them to Cu+ ions [copper(I) sulfate] that are orange/red

the more reducing sugar present, the more precipitate formed meaning there are less Cu2+ in the solution therefore the precipitate is more brick red

Why does the test for non-reducing sugars work?

Hydrochloric acid needs to be added to hydrolyse the non-reducing sugar from disaccharide/polysaccharide to monosaccharides which are always reducing sugars

Emulsion test method and positive result and what it tests for

Tests for - lipids

Method - sample is mixed with ethanol, water is added, shaken

Positive result - cloudy emulsion

Iodine test method and positive result and what it tests for

Tests for - starch

Method - add iodine to sample

Positive result - blue/black colour

Benedict's test method and positive result and what it tests for (non-reducing)

Tests for - Non-reducing sugars

Method - boil sample with hydrochloric acid, add Benedict's solution and heat

Positive result - brick red colour

What is a phosphodiester bond?

The type of bond that links the nucleotides in DNA or RNA.

How does a phosphodiester bond connect nucleotides?

It joins the phosphate group of one nucleotide to the hydroxyl group on the sugar of another nucleotide.

Maltose

disaccharide, 2 alpha glucose monomers, alpha 1-4 glycosidic bond, reducing sugar, found in wheat/pears ect

Lactose

disaccharide, beta glucose and galactose monomers, beta 1-4 glycosidic bond, found in dairy products, reducing sugar

Functional role of nucleotides

nucleotides are the building blocks for nucleic acids and are essential for transferring information to new cells

Glycolipids

Triglycerides

lipid that is made of 1 glycerol and 3 fatty acids

3 ester bonds formed so 3 water molecules removed

insoluble in water

Triglycerides uses

energy storage, thermal insulation, cushioning, buoyancy, electrical insulation, respiratory substrate, energy source for respiration

Lipid properties

non-polar, insoluble in water, soluble in organic solvents like alcohol

what does cholesterol produce

vitamin D, steroid hormones, bile (helps in digestion, is made in liver)

saturated

no double C=C bond, solid at room temp

monounstaurated

1 double C=C bond, liquid at room temp

polyunstaturated

more than 1 double C=C bond, liquid at room temp

esterification

type of condensation reaction

alcohol + acid --> ester + water

role of cholesterol

increase stability of the membrane, reduce fluidity of the membrane (regulate fluidity especially during temperature changes)

how do phospholipids form the bilayer of a plasma membrane

hydrophilic part forms hydrogen bonds with water, the medium in and out of plasma membrane is aqueous, hydrophobic nature of fatty acids result in them facing toward each other

melting point of lipids

less hydrogen atoms means more double C=C bonds, fatty acid chains bend, less uniformly packed, lower m.p.

why can lipids increase the buoyancy of aquatic animals

lipids/fats are less dense than water

phospholipid

a glycerol molecule, two fatty acids, and a phosphate group that is modified by an alcohol.

The phosphate group is the negatively-charged polar head, which is hydrophilic.

The fatty acid chains are the uncharged, nonpolar tails, which are hydrophobic

What are the charges of hydrophobic and hydrophilic parts?

hydrophobic - uncharged (non-polar) - don't dissolve well

hydrophilic - negatively (polar) - polar dissolve well in water

oxygen - negative