biological molecules

Question 1

name 4 monosaccharides

Answer 1

-alpha glucose
-beta glucose
-galactose
fructose

Question 2

what bond is formed when a disaccharide is formed

Answer 2

glycosidic and a condensation reaction forms to bond the monosaccharides.

Question 3

name 3 disaccharides

Answer 3

-maltose
-lactose
-sucrose

Question 4

how is maltose formed

Answer 4

glycosidic bond formed from a condensation reaction joined by a 1-4 glycosidic bond between 2x alpha glucose molecules.

Question 5

how is sucrose formed

Answer 5

an alpha glucose and fructose

Question 6

name the 4 polysaccharides

Answer 6

-chitin.
-glycogen
-cellulose
-starch

Question 7

what polysaccharide stores glucose in plants and contains amylose and amylopectin

Answer 7

starch

Question 8

what is amylose

Answer 8

a polysaccharide with coiled chains of a-glucose and are 1-4 glycogen bonds and takes longer to separate.

Question 9

why is amylopectine different from amylose

Answer 9

amylopectine has 1-4 and 1-6 glycosidic bonds and are strands not coiled connected to form branches so more easily seperated.in plants amylopectine consists of about 70-80 of starch.

Question 10

why is starch insoluble

Answer 10

does not affect water potential of cells.

Question 11

what is glycogen

Answer 11

energy store in animals made of only a glucose and is highly branched for easier break down.

Question 12

what is cellulose

Answer 12

straight chains of b-glucose with no branches held with 1-4 bonds . Are able to form many hydrogen bonds between )H groups of ajacent chains-produces micro fibrils which group to form macro fibrils and group to form cellulose fiber.

Question 13

what does chitin consist of

Answer 13

made of structural b-glucose whcih is rotated like in cellulose and some of the 0H groups are replaced with an amino acid. Cross linkage between these adjacent chains gives structural benefits

Question 14

what can chitin also be referred to as

Answer 14

mucopolysaccharide because contains amino acids.

Question 15

in triglycerides how is the fatty acids and glycerol bonded

Answer 15

3-condensation reactions forming 3 ester bonds.

Question 16

why are tiglycerides not polymers

Answer 16

they are not made of repeating small units of the same molecule.

Question 17

what are the differences between saturated and unsaturated fats

Answer 17

saturated fats are solid at room temp with no double bonds and are most animal fats.more hydrogen atoms in hydrocarbon tale-has a straighter looking structure. unsaturated fats are liquid at room temp with double bonds and most plant fats. fewer hydrogen atoms in hydrocarbon tale.

Question 18

describe a feature of phospholipids

Answer 18

head is hydrophilic wheras the tales are hydrophobic usually joined by a glycerol molecule

Question 19

the phosphate moleule is joined to glycerol by waht bonds

Answer 19

phosphate ester bond forming a water molecule.

Question 20

what happens with phospholipds in water

Answer 20

hydrogens dissociate from phosphoric acid giving the acid a negative charge creating a hydrophilic head as water is polar.

Question 21

use of phospholipds

Answer 21

important for all membranes and they can move around each other so keep the fluidity and keep the membrane stable.

Question 22

what is the role of the bilayer

Answer 22

control of substances in and out.
-electrical insulation e.g mylein sheath. due to its partial permeability.
-thermal insulation.
-only small non-polar molecules can pass e.g oxygen

Question 23

role of lipids

Answer 23

-energy store
-hibernation
-in seeds
-electrical insulation.
-thermal insulation
-organ protection
-structure of plasma mem.
-waterproofing
-buoyancy

Question 24

what does high cholesterol cause

Answer 24

raises low density liipoproteins and atherosclerosis

Question 25

what are amino acids made up of

Answer 25

basic group (amine /amino group) an acidic group (carboxyll), a hydrpgen atom and a residual/variable group.

Question 26

how is a dipeptide formed

Answer 26

peptide bonds between two carboxyll groups through condensation reactions

Question 27

what is the name given to the process of bonding to form polymers

Answer 27

polymerisation

Question 28

what is a secondary protein

Answer 28

the sequence of amino acids causes some amino acids to bend into a-helix shapes or fold into b-peated sheets . Hydrogen atoms bond but in large number s they provide strength.

Question 29

what bonds are tertiary structures held with

Answer 29

disulphide,ionic and hydrogen

Question 30

why does the protein molecule bend and twist in tertiary structures

Answer 30

to achieve max stability at lowest energy state.

Question 31

what quaternary protein has magnesium as its prosthetic group

Answer 31

chlorophyll

Question 32

what are globular proteins

Answer 32

3D folding in tertiary or Quaternary proteins resulting in a spherical shape

Question 33

what are fiborous proteins

Answer 33

long rope like shapes made of secondary and primary proteins

Question 34

fibrous proteins:
polypeptide chains form long twisted strands held together.
-seconday protein
-stable.
-insoluble
-structural e.g keratin

Answer 34

globular:
-polypeptide chains roll up into a spherical shape.
-unstable
-soluble
-metabolic e.g enzymes, antibodies or hormones.

Question 35

what does keratin consist of

Answer 35

2x a-helices twisted together.

Question 36

what does collagen consist of

Answer 36

3x a-helices twisted tightly together held with hydrogen bonds e.g ligaments