Biology biological molecules 3.1.1&2

Card 8 is 3.1.2

the biochemical basis of all life

carbon hydrogen nitrogen oxygen. this is proof of evolution.

what are monomers

basically smaller units from which larger molecules are made.

what are polymers

basically molecules that are made from a large number of monomers

examples of monomers

amino acids, nucleotides and monosaccharides, such as ALPHA GLUCOSE AND BETA GLUCOSE.

Example of a polymer

cellulose, glycogen, and dissaccharides.

a condensation reaction

joins tomolecules together which form a bond and involves the elimination of a molecule of water

A hydrolysis reaction

this breaks a chemical bond between two molecules and involves the use of a water molecule

mono saccharides

they are sugar molecules, they are monomers which make up larger disaccharides and polysacchardies

glucose

c6 h12 o6( hexase)

the monosaccharides

glucose, fructose and galactose

sucrose

glucose+ fructose. sucrose is not a reducig sugar

disaccharides

they are know as nonredcing sugars

Glycosidic bond

this is formed between two monosaccharides. Eg Maltose is made from two alpha glucose joined together by a condensation reaction. these are formed between the OH groups of the C1 and C4

lactose

glucose+galactose.

maltose

alpha glucose +alpha glucose

isomers

Basically molecules with the same molecular formula a different arrangement of atoms withthin the molecule for instance the alpha and beta glucose molecule.

image of isomer on the right.

covelent bonding

when atoms share pairs of electronds in their outer shell and a more stable compound called a moecule isformed

Apolarised molecule

when the charges ar are not spread evely aroudnd the loecule also known as uneven distribution of electrons.

carbohydrates

the carbon atoms readily form bonds with other carbon atoms. therefore a sequence of lengths of carbon atoms are built. these form a “backbon that other atoms can be attache. this permits a large number of different sizes and types of molecules to be based on carbon.

mono saccharides

they are sweet tasting SOLUBLE SUBSTANCES. they have the forula ( CH20)n where n has a range of 3-7

why would a colorimeter improve repaetability

because colour is subjunctive

percentage error

uncertainty/ volume) x100

test for reducing sugars

add solution in test tube. then add benedicts solution, heat for 4 mins and a red precipitate shoud be formed.

test for non reducing sugars

the first biochemical test willl be negative for non-reducing sugars. they need to be neutraised first, which means, the a put in a test tube, then added an acid or HCL . once it stops fizzing sodium hydrogen carbonate (NaHCO3). the beenedicts solutin is added and then placed ina water bath. this is because the disaacharide has been hydrolysedinto monosacchardides.

starch

made from alpha glucose molecules which form a glycosidic bond. they form a helix structure which makes it compact and good for storage. it has branched and unbranched chain. the OH groupp be pointing inwards which form hydrogen bonds that keep them in shape. it is made from amylopectin and amolose

properties of starch

they are large molecules and thereforecannot diffuse out of the cell memebran. the are large molecules therefroe insoluble.so this does not affect their water potential. when hydrolyesed, it easily transported and readily used for respiration. Has many ends so that they are acted on by enzyme acticity. also glucose is released easily. it is also stored in storage organs and seeds, and is found in plants.

glycogen is very

Has very similar to starch but found in ANIMAL CELLS. it is stored in small granues and is shorter and highly branched. ithese granules are found muscles, and liver cells.

celllulose

made of beta glucose molecules arranged parallel to each other and are straight chains with unbranched chains which then form hydrogen bonds that are adjacent and form a linkage between these chains that have collective strength, this makes the cell wall very turgid and non-woody parts of the plant semi turgid.