Biology[Module 2:Biological molecules:Carbohydrates]

what are hydrogen bonds?

weak electrostatic attraction between a slightly positive charged ago and a slightly negative charged atom

what does water consist of?

-2 hydrogen atoms and one oxygen atom covalently bonded

-oxygen has a delta negative charge (stronger affinity)

-h2o is polar

-held by h bonds which helps it sustain life

Properties of water

-density of ice

-solvent

-high specific heat capacity

-high latent heat of vaporisation

density of ce

-ice is less dense then water,so it floats

-ice insulates the water below from freezing allowing aquatic life to survive

solvent

-water dissolves polar molecules by slightly delta negative oxygen molecules becomes attracted to positive ion

high specific heat capacity

-the amount of energy needed to raise the temperature of 1kg of h2o by 1C

-a lot of heat needed to change the temp allowing aquatic life to survive

high specific heat of vaporisation

-Evaporation has a cooling effect:a lot of energy has been lost

carbohydrates

-starch—maltose(by amylase)—glucose(by maltase)

types of carbohydrates

-polysaccharides=many sugars(starch in plant cells, glycogen in animal cells+energy storage molecules)

disaccharide

two sugars

• maltose=glucose+glucose

• lactose=glucose+galactose

• sucrose=glucose+fructose

monosaccharides

one sugar

• glucose(energy source )

• galactose

• fructose

formula for respiration

glucose+oxygen—>co2+h20+ATP

what is a monomer and polymer?

monomer=a single repeating unit

polymer=a large molecule made up of monomers

what is a condensation reaction?

reaction in which water is formed/removed and a bond is formed

what is a hydrolysis reaction?

reaction in which a molecule of water is used and a bone is broken

Types of glucose

-Alpha glucose =has the OH group on C1 below

-Beta glucose=has the OH group on C1 above

what type of bond do carbohydrates make?

glycosidic bond

Benedicts Test(for reducing sugars)

-ass benedict’s reagent to sample in a test tube and heat it up

-a red-brown colour if the test is positive

-reducing sugar are able to donate electrons

Benedicts Test(for non-reducing sugars)

-add HCl to sample and heat to hydrolyse sucrose

-add NaHCO3 to neutralise HCl

-add benedict’s reagent and heat

-red-brown colour if the test is positive

Colorimeter

-used to make the test quantitative

-mesures absorbance

USE:

-place a cuvette with distilled water into the colorimeter and press R to reset the equipment

-place cuvette containing solution into the colorimeter and press T to test

structure of amylose

-in plants

-long chain of alpha glucose

-glycosidic bonds between carbon 1-4

-helical shape

-compact=less space

-hydrogen bonds

-hydroxyl group on c2=less soluble=allowing hydrogen bonds to from to maintain the structure

structure of amylopectin

-in plants

-helical shape

-hydrogen bonds

-glycosidic bonds between carbon 1-4 +branches formed by glycosidic bonds between carbon 1-6

structure of glycogen

-in animals

--glycosidic bonds between carbon 1-4 +branches formed by glycosidic bonds between carbon 1-6

-more branches=more compact=easier to remove monomer units as there are more ends

-more branches=enzymes can easily access and rapidly hydrolyse into glucose for respiration

-insoluble=not affects water potential in cells

-compact=can store a lot of glucose molecules

structure of cellulose

-in plants

-beta glucose joined by condensation reaction

-1-4 glycosidic bonds

-many hydrogen bonds which gives high tensile strength =they can resist pulling forces without breaking

-unreactive+insoluble