biological molecules

Question 1

what is a monomer?

Answer 1

repeating subunits that make up a polymer

Question 2

What is a polymer?

Answer 2

a chain of monomers

Question 3

What is a condensation reaction?

Answer 3

Forming bonds between between monomers, water is produced

Question 4

What is a hydrolysis reaction?

Answer 4

Breaking bonds between polymers, water used

Question 5

Give two examples of biological polymers

Answer 5

Proteins
Polysaccharides

Question 6

Give three examples of biological monomers

Answer 6

Monosaccarides
Amino acids
Nucleotides

Question 7

What is the general formula for carbohydrates?

Answer 7

(CH2O)n

Question 8

What are monosaccarides?

Answer 8

. Sweet tasting soluble substances
. Glucose, fructose, galactose

Question 9

where is starch found and what is it made of?

Answer 9

. plants
. amylose and amyloplecin

Question 10

what is the structure of starch?

Answer 10

. compact (due to coiled and branched chains)
. insoluble so does not effect osmotic properties of cell

Question 11

what is the function of starch?

Answer 11

. storage of energy in plants
. lots of glucose can be fit in a small space due to coils

Question 12

where is glycogen found and what is it made of?

Answer 12

. animals
. alpha glucose

Question 13

what is the structure of glycogen?

Answer 13

. even more coiled and branched than amylopecin
. insoluble so does not effect osmotic properties of cell

Question 14

what is the function of glycogen?

Answer 14

. main energy store in animals
. lots of glucose so can fit in small space due to coils

Question 15

where is cellulose found and what is it made of?

Answer 15

. cell walls of plants
. beta glucose and hydrogen bonds

Question 16

what is the structure of cellulose?

Answer 16

. long and unbranched
. held together by hydrogen bonds
. large numbers of beta glucose chains
. layers on top of eachother

Question 17

what is the function of cellulose?

Answer 17

. structure
. many chains together in layers to form microfibril and fibril to keep cell wall strong

Question 18

what is the structure of lipids?

Answer 18

. contains C,H,O
. O:C:H smaller than carbohydrates
. insoluble in water
. soluble in organic solvents (acetone and alcohol)
. tryglycerides and phospholipids

Question 19

how are lipids used in cell membranes?

Answer 19

. cell surface membrane and around organelles
. phospholipids contribute to flexibility of membranes and transfer of lipid-soluble substances

Question 20

how are lipids a source of energy?

Answer 20

. when oxidised, provide more than 2x energy of carbs and release valuable water

Question 21

how are lipids waterproof?

Answer 21

. insoluble in water, waxy lipid cuticles that conserve water
. mammals have oily sector

Question 22

how do lipids provide protection?

Answer 22

. stored in delicate organs such as kidney

Question 23

how do lipids provide insulation?

Answer 23

. slow conductors of heat, can help retain body heat
. act as electrical insulators around mylen sheath in nerve cells

Question 24

what are properties of tryglycerides?

Answer 24

. glycerol and 3x fatty acids
. condensation reaction for fatty acid bond
. ester bond with glycerol
. glycerol is the same in fats and oils
. variations in fatty acids
. over 70 different fatty acids
. all have -COOH group with hydrocarbon
. saturated= c-c
. unsaturated= c=c

Question 25

what is the structure of phospholipids?

Answer 25

. 2 fatty acids and glycerol . inorganic phosphate group in place of 3rd fatty acid

Question 26

how can phospholipids be described as polar?

Answer 26

in an aqueous environment, phospholipid molecules from a bilayer within cell surface membranes

Question 27

how do they have hydrophyllic heads?

Answer 27

faces water and helps to hold at cell surface membrane

Question 28

What can be made of proteins?

Answer 28

. Hair and skin contain a protein called keratin . They make haemoglobin (o2 carrying RBC) . Bones contain a protein called collagen . Hormones such as insulin are often proteins . Found in cell membranes

Question 29

How many different amino acids are there?

Answer 29

20

Question 30

What are primary structure proteins?

Answer 30

The sequence of amino acids in a polypeptide or protein

Question 31

What are secondary structure proteins?

Answer 31

The regular folding or coiling of the polypeptide chain due to the formation of hydrogen bonds

Question 32

What are tertiary structure proteins?

Answer 32

The unique 3D folding of the polypeptide chain

Question 33

What are quaternary structure proteins?

Answer 33

The 3D arrangement of 2 or more polypeptide chains, often involving a prosthetic group

Question 34

What are the qualities of enzymes?

Answer 34

Increased temperature makes molecules move faster Biological systems are very sensitive to temperature changes Increase RoR without increasing temp Create a new reaction pathway "short cut"

Question 35

What is free energy?

Answer 35

Energy available the enzymes need to perform work

Question 36

What is the structure of enzymes?

Answer 36

Have a specific 3d shape Specific region of enzyme is functional- active site Small depression in enzyme molecule Substrate fits into depression to form enzyme-substrate complex Substrate is held by temporary bonds that form between certain amino acids of active sites and groups of substrate molecules

Question 37

How does the lock and key model explain denaturation?

Answer 37

Breaking of peptide bonds within the structure

Question 38

What is the induced fit model?

Answer 38

Substrate and active site not entirely complimentary Can change shape - conformation When Substrate bonds with enzyme, induces change in enzymes conformation Active site moulded into precise conformation Bonds stretched to make reaction easier Chemical reaction is suitable

Question 39

What factors effect enzymes?

Answer 39

Substrate concentration Ph Temperature Inhibitors

Question 40

What are competitive inhibitors?

Answer 40

Structurally similar to substrate Blocks active site Cannot react with enzyme

Question 41

What are non competitive inhibitors?

Answer 41

No structural similarity to substrate Binds to site other than active site Binding changes shape of active site

Question 42

How does substrate concentration effect enzymes?

Answer 42

. Faster reaction until it reaches saturation point when enzyme molecules are occupied . If you alter concentration of enzyme then Vmax will change too

Question 43

How does pH effect enzymes?

Answer 43

Extreme pH can produce denaturation Structure of enzyme changed Active site distorted Is pH values are slightly different from optimum small changes to enzyme and substrate occur Change in ionisation effects binding

Question 44

How does temperature effect enzymes?

Answer 44

Enzymes are not denatured at cold temperatures As temperatures increase, substrate and enzyme have more kinetic energy High temperatures cause denaturation Changed due to excessive movement within the enzyme and the ionic and hydrogen bonds break Substrate will no longer fit