carbohydrates and proteins

Question 1

what are the simplest carbohydrates ?

Answer 1

monosaccharides/sugar monomers

Question 2

can the carbon skeletons of monosaccharides vary in length ?

Answer 2

yes

Question 3

what makes monosaccharides useful ?

Answer 3

they are the main fuel for cellular work
used as raw materials to manufacture other organic molecules

Question 4

whats the name for monosaccharides with only three carbons ?

Answer 4

trioses

Question 5

whats the name of monosaccharides that have 5 carbons ?

Answer 5

pentoses

Question 6

whats the name of monosaccharides that have 6 carbons ?

Answer 6

hexoses - these are also structural isomers

Question 7

what are the 3 common disaccharides ?

Answer 7

sucrose, lactose and maltose

Question 8

what do we know about sucrose ?

Answer 8

is table sugar and is also used in plants as the molecule to transport sugar around

Question 9

what do we know about maltose ?

Answer 9

found in seeds like wheat or barley and produced as part of the breakdown of starch to glucose

Question 10

what do we know about lactose ?

Answer 10

is milk sugar

Question 11

what are glycosidic bonds ?

Answer 11

they are covalent bonds that form between a carbohydrate and another molecule

Question 12

what can polysaccharides function as ?

Answer 12

storage molecules or structural compounds

Question 13

are polysaccharides usually hydrophilic or hydrophobic ?

Answer 13

hydrophilic

Question 14

what are the biologically important polysaccharides ?

Answer 14

starch, glycogen, cellulose, chitin

Question 15

what are the features of starch ?

Answer 15

is composed of glucose monomers
used by plants for energy storage

Question 16

what are the features of glycogen ?

Answer 16

composed of glucose monomers
used by animals for energy storage

Question 17

what are the features of cellulose ?

Answer 17

is a polymer of glucose
forms plant cell walls

Question 19

what version of glucose does cellulose have ?

Answer 19

beta version

Question 20

what version of glucose does glycogen have ?

Answer 20

alpha version

Question 21

what are the features of chitin ?

Answer 21

used by insects and crustaceans to build an exoskeleton
found in the cell walls of fungi

Question 22

the hydrolysis of storage polysaccharides such as glycogen, release glucose when …

Answer 22

energy demand is high

Question 23

do glycogen stores last long ?

Answer 23

no

Question 24

in human how long would it take for the glycogen store to be depleted without food ?

Answer 24

within a day

Question 25

what do enzymes do ?

Answer 25

serve as catalysts and regulate virtually all chemical reactions within cells

Question 26

what bonds link amino acid monomers together ?

Answer 26

peptide bonds

Question 27

how are peptide bonds formed ?

Answer 27

through dehydration reactions joining the carboxyl group of one amino acid to the amino group of the next amino acid

Question 28

side chains can be ...

Answer 28

hydrophobic (greasy and lipophilic) h-bonding (more polar and hydrophilic) charged (either negative positive, polar and hydrophilic)

Question 29

what do we know about hydrophobic side chains ?

Answer 29

all of these side chains are greasy and would break up the h-bonding network of water. they are lipophilic and very happy in a cell membrane

Question 30

what do we know about h-bonding side chains ?

Answer 30

all of these can act as h-bond donors or acceptors. this makes them much more hydrophilic and less lipophilic. they can also interact with other parts of the protein chain

Question 31

what do we know about positively charged side chains ?

Answer 31

all of these side chains will be protonated at a physiological ph. they can also h-bond as well as being attracted to negative charges, and they are polar.

Question 32

what do we know about negatively charged side chains ?

Answer 32

these have a carboxylic acid in their side chain which will be largely deprotonated at a physiological ph. this makes them polar, hydrophilic/lipophobic and attracted to positive charge

Question 33

what is the primary structure ?

Answer 33

the sequence of amino acids in a polypeptide chain

Question 34

what is secondary structure ?

Answer 34

the formation of secondary structures such as alpha helices and beta pleated sheets -these form because of hydrogen bonding between different amino acids in the chain

Question 35

what is tertiary structure ?

Answer 35

when the secondary structures fold up to form a very precise three dimensional structure

Question 36

what are the forces responsible for the formation of tertiary structure ?

Answer 36

hydrogen bonds ionic bonds disulphide bonds van der waal's forces

Question 37

what can split hydrogen bonds ?

Answer 37

high temperatures and an altered pH

Question 38

how can ionic bonds be split ?

Answer 38

by changing the ph

Question 39

how can disulphide bonds be split ?

Answer 39

by reducing agents

Question 40

what are van der waals forces ?

Answer 40

these are weak forces of attraction between non-polar groups .

Question 41

how are van der waal's forces split ?

Answer 41

split by a rise in temperature

Question 42

what are the features of fibrous proteins ?

Answer 42

fibrous protein molecules form long chain or fibres their fibrous nature makes them insoluble in water and this makes them useful for structure and support

Question 43

what is the structure of fibrous proteins ?

Answer 43

fibres form a triple helix of polypeptide chains these chains are held together by hydrogen bonds

Question 44

if a proteins shape is altered, it can no longer ...

Answer 44

function

Question 45

what happens to a protein in the process of denaturation ?

Answer 45

it unravels loses its specific shape and loses its specific function

Question 46

what can denature proteins ?

Answer 46

by changes in salt concentration, changes in pH, or high heat