proteins, polysaccharides and lipids

Question 1

describe alpha helixes

Answer 1

rod like, found in strong extensible proteins, stabilised by H bonds

Question 2

describe beta pleated sheets

Answer 2

zig zag chains, several side by side, parallel or anti-parallel, found in flexible proteins

Question 3

describe triple helixes, and state which molecule they are found in

Answer 3

found onli in collagen, strong and water-soluble, no H bonds in each chain but 3 chains held together by H-bonds

Question 4

name 4 groups of proteins

Answer 4

fibrous, globular, membrane and messegner

Question 5

describe fibrous proteins

Answer 5

insoluble, metabollicaly unreactive, structural (collagen, keratin, fibres etc)

Question 6

describe globular proteins

Answer 6

hydrophillic, backbone fold on itself, water-soluble

Question 7

describe the 2 types of membrane proteins

Answer 7

Peripheral:
. on surface of membrane
Integral
. within bilayer
. channel proteins facilitate movement of small molecules and carrier proteins bind to transporter molecules

Question 8

state the function of messenger proteins

Answer 8

allow cells to communicate with one another

Question 9

state the building blocks of polysaccarides and give some examples of polysaccharides

Answer 9

monosaccharides

ex- starch, glycogen, cellulose