biological molecules

what Is a monomer

small units that make larger molecules

what is a polymer

made from large number of monomers and chemically bonded

examples of monomers

monosaccharides , amino acids , nucleotides

what is condensation reaction

joins 2 monomers together with formation of covalent bond and involve elimination of water

what is hydrolysis reaction

breaks covalent bonds between 2 monomer

involve use of water molecule

describe molecules of life

all contain carbon, hydrogen, oxygen

these are organic

can be grouped into 4 types, carbohydrates, lipids , proteins , nucleic acids

which make up biochem process of life

what can the monomer of glucose make polymers of

starch, cellulose , glycogen

what can the monomer of amino acids make a polymer of

protein

what can the monomer of nucleotides make a polymer of

DNA & RNA

examples of carbohydrates

monosaccharides, disaccharides, polysaccharides

examples of monosaccharides which are monomers

glucose

fructose

galactose

examples of disaccharides (dimers)

sucrose

maltose

lactose

examples of polysaccharides (polymers)

starch

cellulose

glycogen

describe glucose

exist as 2 isomer alpha and beta

found in all 3 polysaccharides

for the drawing, the right side is swapped for beta

what do molecules of life all contain

carbon, hydrogen and oxygen

all organic

what 4 groups can carbon hydrogen and oxygen be grouped into

carbohydrates, lipids, proteins, nucleic acids

describe carbohydrates

respiratory substrate

provides energy for cells

used for structure in cell membrane and cell wall in plants

describe lipids

respiratory substrate

provide energy for cells

form a bilayer in cell membrane

make up some hormones

describe proteins

main component of many cellular structure

form enzyme & chemical messengers

describe nucleic acid

form polymers (DNA & RNA)

which makes up genetic material of organisms

codes for sequence of amino acids

which make up all proteins

what are long chains of sugar units called

saccharides

what is a single monomer , pair of monomers and many called and what bonds join them together

monosaccharide

disaccharide

polysaccharide

glycosidic bonds in condensation reaction

what bonds is formed from condensation reaction between 2 monosaccharides

glycosidic bond

how is a disaccharide formed

condensation of 2 monosaccharides

how is the disaccharide maltose formed

condensation of 2 glucose molecules

how is the disaccharide sucrose formed

condensation of glucose and fructose

how is the disaccharide lactose formed

condensation of glucose and galactose

how are polysaccharides formed

condensation of many glucose units

how is glycogen and starch formed

condensation of alpha glucose

how is cellulose formed

condensation of beta glucose

describe structure of glycogen

long branched chains w lots of side branches

glycosidic bonds = 1-6

large but compact, maximising amount of energy stored

properties of glycogen

lots of branches increases SA, so enzyme can hydrolyse glycosidic bonds

which allows glucose release quickly

insoluble , doesn’t affect water potential of cells & can’t diffuse out cells

uses of glycogen

animal store excess glucose as glycogen in muscles and liver

glycogen= energy store, can be hydrolyse to release glucose quick for respiration

describe structure of starch

mix of 2 polysaccharide , amylose & amylopectin

amylose=long & unbranched , forms coils

amyloplectin=long, branched cuz of 1-6 glycosidic bond

properties of starch

amylose=coiling so is compact & store more in a smaller place

amylopectin=branches increase SA for enzyme to hydrolyse glycosidic bonds

which allows quick release of glucose

insoluble , won’t affect cell water potential

uses of starch

plants use to store excess glucose

cuz its too big to leave cells

starch can be hydrolyse to release glucose for respiration

describe structure of cellulose

long

unbranched

straight chains

glycosidic bonds 1-4

cellulose chain link by H bonds between glucose molecules in each chain

which forms thicker fibres (microfibrils)

component of cell walls in plant

properties of cellulose

H bonds between cellulose make microfibril really strong

but its still flexible allowing to provide support

uses of cellulose

major structural component

provides support

allows cell to become turgid

which also helps maximise SA of plants for photosynthesis

formula for monomer & trisaccharide

C6H1206

C18H32016

Describe lipids

biological molecules made from carbon, hydrogen , oxygen

only soluble in organic solvents

main types = triglycerides & phospholipids

roles of lipids

energy source

waterproofing

insulation

protection 

describe the role of lipid as an energy source

can be a reactant in respiration to release energy

to make ATP

describe the role of lipid for waterproofing

its insoluble

creates layer around plants & animals for water retain

describe the role of lipid as an insulator

poor conducts of heat & electricity

describe the roles of lipid for protection

protects around delicate organs

describe triglyceride structure

glycerol molecule & 3 fatty acids

ester bond formed in condensation between each 3 OH group on glycerol & OH group of each fatty acid chain

non polar

describe phospholipid structure

glycerol, phosphate group, 2 fatty acid chain

ester bond formed by condensation reaction between 2 OH group on glycerol & OH group of each fatty acid chain

describe saturated lipid

found in animal fats

no carbon carbon double bond

describe unsaturated lipid

in plants

carbon-carbon double bond

can bend- so can’t pack together tightly so liquid at room temp

describe triglycerides fatty acid chain

hydrophobic so insoluble in water

so doesn’t affect water potential

why is triglyceride good energy store

high ratio energy storing C-H bonds to C

in small space

when hydrolyse lots of energy released

good for animals carrying less mass

why does triglyceride release water when oxidised and why’s this good

high ratio of H-O atoms

source of water for organisms in dry environment

properties of phospholipid

phosphate head = hydrophilic 

fatty acid = hydrophobic 

so forms micelles in water contact 

so they’re polar & can form bilayers making up membranes 

what can phospholipids form and the importance of this

can form glycolipids w carbohydrates

which is important on cell surface membrane for cell recognition

what is liposome for

transport water soluble substances in cells

what is micelles for

transport of lipid soluble substances

describe phospholipid bilayer 

head = hydrophilic but tail=hydrophobic

in water form double layer

head face towards water , tail = opposite

centre=hydrophobic ——> so water soluble substance can’t easily pass 

creates barrier & solution separation 

describe water

polar molecule due to uneven distribution of charge

liquid at room temp

BP = 100 degrees

Hydrogen bonds

why is water polar molecule

uneven distribution of charge

unequal sharing of electron give H2O molecule slightly negative charge near its oxygen

and slightly positive charge near H atoms

describe water being liquid at room temp

mostly small molecules like water = gas at room temp

but interactions between water molecules = stronger

describe the hydrogen bonds in water

result of polarity

individually weak

collectively strong

properties of water

its a metabolite

its a solvent

has high specific heat capacity

has high latent heat of vaporisation

H2O molecules are cohesive

describe water as a metabolite

metabolism= collective name of them reaction in organism

metabolite= chemicals involved in metabolism

its metabolite in reactions like condensation, hydrolysis —→ usednin forming & breaking bonds

describe water as a solvent

good solvent cuz its polar—→ allows ions & polar molecules to dissolve easy as they’re attracted to poopsoite charges on H2O molecules

ionic compounds & polar substance dissolve in h2o—> so them reaction can happen, substance can be transported

non polar like lipid & v large molecules aren’t soluble in water

describe water having high specific heat capacity

can absorb lots of energy without changing temperature by much

why does water have high specific heat capacity

H20 molecules stick together with H bonds

so lots energy required to break these bonds

so H20 can act as a temperature buffer

benefits of water having high specific heat capacity

can act as a temp buffer

help maintain stable aquatic system

help organism maintain consistent temp , therefore maintaining consistent activity

describe water having high latent heat or vaporisation

takes lots energy to evaporate 1kg of h20

why does water have high latent heat

lots energy required to overcome H bonding between h20 molecules

describe the effect of having high latent heat in terms of sweating

sweating is effective means of cooling

cooling effect with little water loss

describe h20 molecules being cohesive in water

H bonds make H2O MOLECULES STICK TOGETHER

benefit of h20 molecules being cohesive

chains of h2o can be pulled up xylem

causes surface tension to provide habitat to support ecosystem 

describe the property of solid water being less dense than liquid

when h20 freeze, h bonds become longer

so particles more spread out

and in a crystalline structure compared to when liquid

how is solid water being less dense than liquid make it a useful property

frozen water can provide habitats to support ecosystems

what is the monomener making up proteins

amino acids

how are peptide bonds formed

condensation reaction between 2 amino acids

peptide bonds form between amine group of 1 amino acid & carboxyl group of other

h2o molecule released

how is dipeptide bond formed

2 amino acids join by condensation

carboxyl group of 1 amino acid react w amino group of another

how is polypeptide bond formed

condensation of many amino acids

describe proteins

can be globular or fibruous

catalyse reactions or movement of substance across phospholipid bilayer

enzymes made of proteins

describe globular proteins

have role in cell signalling

describe role of fibrous protein

have structural role

describe protein struc

polymers made of monomers of amino acids

20 amino acids

contain hydrogen, oxygen, also nitrogen

R group made of fdiff elements

what does the r group in proteins cause and mean

means they have diff properties & interact with other molecules diff

affects protein shape

describe primary struc of protein

the sequence of amino acids joined by peptide bonds in polypeptide chains

contain initial sequence of amino acid

so determine protein function

describe secondary struc of protein

polypeptide chain coil into alpha helix or fold into beta pleated sheets

structures held bh H bonds, forming between amino acids in chain

many H bonds make struc stable

describe tertiary struc of protein 

3d shape of polypeptide chain

specific shape created cuz of sequence of amino acids

H bonds , ionic bonds , covalent form between R groups

why does change of amino acids affect secondary and tertiary structure

cuz bonds would form in diff places

changing temp/ph of solution the protein is in could also affect bonds, which affects secondary and tertiary struc so function affected

describe quaternary struc of protein

proteins made from more than 1 polypeptide chain

H bonds , ionic, covalent form between polypeptide chain

to hold quarternary struc together

enzyme function

increase rate of reaction by lowering activation energy

also catalyse specific metabolic reaction at cellular level

eg respiration, photosynthesis

structure of enzymes and how the shape is determined

3D tertiary structured globular proteins

shape determined by primary sequence of amino acids

describe active site of enzyme

has specific tertiary structure which is complimentary to substrate

only binds to certain substrate

ES complex form when enzyme bind to substrate

what happens when enzyme reaction done

product leaves active site 

enzyme goes and makes more ES complex 

how do enzymes speed rate of metabolic reaction

lowering activation energy

usually allow reaction to happen at lower temperature than without enzyme

how does allowing the reaction to happen at lower temp with enzyme increase rate

enzyme either hold substrate close tg

reducing repulsion & allowing them to bond easier/ put more strain on bonds of substrate

allowing them to break apart easier

describe lock and key enzyme model

shape of active site = exactly complimentary to substrate

substrate fit in exactly when they collide, forming ES complex

describe induced fit enzyme model

shape of active site=not exactly complmentary to substrate 

when substrate collide w enzyme , active site can slightly change shape to fit around substrate 

& form ES complex

describe how increasing enzyme conc affects rate

rate of reaction increase

cuz more active sites for substrate to bind to

increasing beyond certain point has no effect on rate

cuz there’s more active sites than substrate

substrate can become limiting factor

describe how increasing substrate conc affects rate

rate increase

cuz more substrate molecules

more collisions=more ES complex

rate slows as enzyme conc becomes limiting fac

rate follows curve cuz when lots active sites alr occupied, there’s reduced chance of successful collision of enzyme & active site

describe how increasing temp affects rate

initially rate increases

cuz molecules have more KE= move faster

increasing num of successful collisions 

increasing num of ES complex

once optimum temp reach rate go down

at high temp enzyme denature→tertiary struc of AS permanently changed

heat energy broke bonds holding T struc so AS not complimentary , so no more ES complex

cuz substrate can’t fit