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Flashcards in Biology (Biological molecules) Deck (104)
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1
Q

metabolic reactions are?

A

sum of all chemical reactions in body

2
Q

catabolic reaqctions are

A

break down larger molecules into samller oens

3
Q

anaolic reactions are?

A

build smaller ones up into lagrer ones

4
Q

monomers and polymers?

A

thousands of monomers make up a polymer

5
Q

respiraion where you break down glucose is a?

A

catabolic reaction

6
Q

Animals and plans have enzymes that onyl break down?

A

alpha glucose

7
Q

carbodydatrets are?

properties

A

sugar units

soluble in water/form crystals

8
Q

names by?

A

number of carbon atoms e.g. 3-carbon>triose

9
Q

glucose is ?

A

hexose sugar

10
Q

general formula of carbohydrates?

A

CnH2On

11
Q

differences in alpha and beta glucose strcutre?

A

al;pha glucose OH and H same on both sides

beta glucose- oppsotite on either side

12
Q

joinging 2 monosacchairdes in a condenssation reaction makes a ?

A

dissacharide

13
Q

starch is?
1-4..?
water potential?
dense?

A

1-4 glycisidic bonds
mainly straight-chained amylose which can form helical chains>coil so pack desnely pack repitaroy substrates
hold ,pre per unit volume
insoluble- not affected by celluakr water potential

14
Q

glycogen is?
1-6..?
solule?
quicly relseae enrgy?

A

1-6 glycosidic bonds
branched>can’t compact closely together>hold less energy per unit volume
ut can relseae energy quciker as more readiyl hydolsed by enzymes
soluble- can affect cellualr water potential

15
Q

cellulose
parrallel chains?
beta glucose?

A

Beta 1-4 glycsidic bonds
moelcules form hydorgoen bonds with neighbouring moolecule not itself, so they lie parrale to each ohtrer with hydoyl groups alternately (180 degrees) between each
insoluble- doesn’t affect water potential

16
Q

several bundles fo moleculs lying parrael are?

A

microfibrils

17
Q

Several microfibrils join toether to make?
strength?
guard macrofibrils?

A

macrofibrils
whcih priovde great emchanical strength and suppro to cell wall
cross-links to provde supprot
contorl fucntions e.g. guard marcofibrils allow opening/clsong of stomata

18
Q

lipids are?

A

molecuels that contain carbon, hydroegn and oxugen

insoluble in water

19
Q

lipids are used in?

A

membranes/ hormoens like choelrterol

20
Q

glycerol and fatty acids make up fats/oil..glycerol is always?

A

the same but fatty acuids differ

21
Q

essential fatty acids means?

A

can’t build up in body>take in as part of diet

22
Q

saturated fats means?
unhealthier
solids at..

A

as much hydrogen is joined as possible is hjoined so solid at room temerature
animals contian a lot of these
unhealthy

23
Q

unsaturdtaed fats mean?
kink
fluid

A

C=C- nt all hydoegns are joined
held looslely- more fluid>tend to be oils>more in plants
healthier
kink in fatty acid chain

24
Q

Tricgkyercide is?

A

3 faty acids + 1 glycerol molecule

25
Q

Properties of triglycerides?
soluboltiy?
energy strorage?
thermal insuakltion?

A

repel water molecules>hydorphobi -not elctricla charge
densely pack substtares- energy stroage
insolubel- nto afected by water potenil
thermakl insualtin in tissues (adipose tissues)

26
Q

phosloipids are amde up of?

A

2 fatty acids+ 1glycerol + 1 phosphate group

27
Q

why is the phospate ‘head’ hdrophilic?

A

attratced to water moeciles

0 has delta negative charge on it- attratced to dleta positive charge on hydogen atoms inw ater molecules

28
Q

fatty acid tails are?

A

hydrohobic- inner bit of membrane- repel water while hydorphilic heads stay ont he outside of membranes close to wtaer

29
Q

phoislipids make up the?

A

bilayer (membrane)- seprate cell contents/les substances diffuse in/ cell signalling

30
Q

fatty acids may be?

cold climates

A

unsaturated- membrane is mroe fluid- in colder climates- this is ideal in low temps
saturated- more solid- less flexible

31
Q

Animals in colder climates have?

A

thick layer so adipose tissue (triglycerides)storage moleules- store vitamin A and D

32
Q

phos[ahes can ahve carbohydrate?

A

chains attached to them- cell signalling

33
Q

Choeleterol is a ?
diffusion
fludiity

A

lipid hormone

  • dissuse starght thorugh bilayer though simple diffusion
  • sits in between fatty acid tails>stabiltiy
34
Q

hgih levels of Cholesterol means?
bile
inner linigns?

A

lumps.gallstones

innerlinings>desposits>atherclesosis

35
Q

Proteins are ….. joined together yb thousands of?

A

polymers

monomers- amino acids

36
Q

strucure of amino acid has R group..?

A

differnt for every amino acid

20 of them- each amino acid in chain- possiblity out of 20

37
Q

amino acid in plants?

A

maunfacure them from niortates in soil

38
Q

essenail amino acids for animals?

vegetarians- protein source?

A

some digest amino aicds.buidl up proteins

some we can’t build up- have to take them in diet like meat so important vegetarians find proteion souce e.g. soya beans

39
Q

What happenms if too many amino acids

A

toxic- have to be remvoe dby deanimation

40
Q

protein is?

A

one or more polypeptide chains joined together

41
Q

called amino acid residue as?
enzymes?
ezymes that break down protien are?

A

some removed in condesnation reation
covalent bonds are very strong- enzyems haev to catalyse reaction in condensation/hydolsis
protease enzymes- digest food, hormones- vital so effects arem’t premamnt, aging- skin loses elacsitiy/ability to rebuild collagen

42
Q

proteins/polypetides aresyntheised on?

A

ribosomes-deterined by mRNA orders the amino acids in a partiuclar sequence
differne protiens- differnt mRNA has to pas throgh ribosomes

43
Q

pimary strucure is?

A

basic sequnce of amino acids

44
Q

seocndary strucure is?

A
amino acids coil or fold to form alpha helix or beta pleated sheet
hydogen bonds (N-H and C=0)- weak but many togther priovide strength
45
Q

tertiary strucuture is?

vital to funciton?

A

alpha helix/beta pleated sheet fold on themsleves to form 3D shape.c Held togethr by many bonds
vital to strcuure e.g. hormone must have complemntayr shape to receptor

46
Q
Bonds in tertiary strucure?
disulfide
ionic
hydrogen
hydrophilic/hydrophobic interactions?
A

disulfide- amino acid cysteine- between sulfur atoms- covanlent
ionic- oppsitely chargfed R groups near each other
hydorgen- delta positive and negative (N-H and C=0)
hydorhilic/hydrophobic- amino acids inwards and outwards in a water-based environemnt

47
Q

Ehat happens if hea is appleid to tertiayr structre?

A

kinetice enrg cuases bonds to vibrate>brekas some of them (wekaer ones liek hydorgen/ionic bonds)>distorts the 3D shape
ebough heat is applied>strucure will unravel) protein becomes denatued (stops functioning)

48
Q

Quaternary strcuure is?

A

protien with more than one polypeptide chain or a one and an inorgainc component

49
Q

haemoglobin has quaternary strcure
subuntis (chains)
prosthtic group

A
4 polypeptide chians/sub-units
2 alpha/ 2 beta
prosthetic grop - Fe 2+ haem group
globular ptotein- metabolic roles/soluble in water
alpha helix
50
Q

How ia the atrcuure of ahempglobin adapete dto its function

3D tertiary shape- carry oxygen to tissues

A

haem group can bind to oxygen
4 haem sites- bidn up to 4 oxygen molecuels
oxygen + haempglobin > oxyhaemoglobin
transport oxygne to repsiring tissues
3D shape-no nulcues so can pack full of haempglobin/large SA so can carry ltos of oxygen

51
Q

Collagen is a ….. protein so is……in water?

A

fiborous protein- strucural roles- insoluble inw water

52
Q

Collagen is made up of?
popypptide chains
left-handed alpha helix?
amino acids?

A

3 poplypetide chains wound in a left-handed helix strucure (makes it more fiborous)
35% of glycine, proline, alaline

53
Q

How does the strucute of collagen adaopt it to its function?
hydrogen bonds?
covalent bonds
cross-links

A

hydrogen bonds wihthing heli strucure- strength
collagen molecuels form cross-links with neighbouring ones addign strenght/stabiltiy
cross-links are staggered- adding strength

54
Q

What is collagen’s role in body?

A

tendons (made of collagen) attach skeltal muscle to bones
cartilage/connectiove tissue- provides strenght for trachea/bronchi
inner walls of arteries- blood at high pressure

55
Q

Starch test?

A

add iodine

changes form yellow/brown to blue/black

56
Q

reducing sugars test?
colourimeter?
calibration curve?

A

bendicts soltion (copper ll sulfate)
changes to red ppt
more preicpitate ther is tell how much bendedicts solution used up>filtrate it
put contents into cuvette>put in sample chamber>photoelectric cell picks up light [shows reading of light passed through)>more benedicts solution used- less light will be blocked [ light transmission increases]
plit a calibration curve of concentration of sugar (x axis) agaisnt % light transmission (y axis)

57
Q

non-reducing sugar test?

A

2 samples- beendicts sotution0 make sure there are no reducing sugars
if not- boil other with dilute hydrochloric acid>solits dissacharides (like sucrose- non-reducing sugar) into its monosaccharides (glucose and fructose)
carry out benedicts solutin again>postivie

58
Q

lipids test?

A

dissolve in ethanol

shake it with ethanol>decant into test-tube>cloudy white emulsion

59
Q

proetins test?

A

biruet reagent
add it in equal voume to sample>down side of test-tube
blue ring>dissolve to violet colour

60
Q

water is polar so?
electron density
hydrogen bonds making/breaking

A

unssymetircal electorn density

continaulyl maing/brekaing hydroge bonds- moving around

61
Q

What does the strong hydrogen bonds mean in relation to keep large bodies of water stable?

A

becaus ethye makes bonds that are hard to break>needs a lot fo heat energy to heat up it
large bodeis of water liek oceans need a lot of heat energy>stay fairly stabke>provide a constant environment for organims

62
Q

What does hdogen bonds mena in terms of freezing?

ice?

A

as you reduce temp>less kinetic enrgy>move around less>don’t breka bonds as easily
held in a solid semi-crystalline strucure called ice
less dense than water>floats on top of water>insulates water below so sustains life under water
habiat for polar bears (floating ice-packs)

63
Q

What does evaporation from surface of water do

humans?

A

cools it- keep temp constant

humans- sweating/dogs- panting

64
Q

cohesion forces due to hydoregn bonds mean?

plants?

A

stick toger-pulled pu as pne continous colum

xylem vessles.used to trrasnprot water up plant

65
Q

wate provides a medium like?

A

blood (humans) and vascualr tissue (plants)

66
Q

as water is polar when polar molecules ..?

metbaolc processes?

A

mix>dissolve as delta postiive oxygn and delta positive hydrogen cluster round oppsotie parts in moelcules_keeops them seprate
once dissolved-move around freely>metaboli processes
e.g. ions (minerals/vitamins) dissolve easily>respiration/hotosynthesis

67
Q

Nucleotides are?

A

Monomers of nucleic acids

DNA = deoxyribonucleic acid

68
Q

Components of nucleotides are?

A

Phosphate group
5-carbon sugar
Nitrogenous bases

69
Q

Condensation reactions?

A

Form between phosphate group (loses a hydrogen off 1 hydroxyl group) and sugar
Sugar and base
Strong covalent bonds in nucleotides and between them to join chains together

70
Q

As nucleotides are bonded together?

A

Repeating sugar-phosphate backbone with bases projecting inwards
Sequence of bases that provide the coded information in DNA

71
Q

Only sugars that are?

A

The same bind together so nuclei acids can only be DNA or RNA

72
Q

DNA is?

A

Double stranded
Purines- adenine which matches to pyrimidine thymine
Purine- guanine which matches to pyrimidine cytosine

73
Q

RNA is?

A

Single-stranded
Purine- adenine matching with pyrimidine uracil
Purine- guanine matching with pyrimidine cytosine

74
Q

In DNA the two strands?

A

Coil together to form a double helix

75
Q

Thy are said to be anti?

A

Parallel as the two strands run parallel but opposite to each other
Left-side goes 5(prime)>3
Right side goes 3(prime)>5

76
Q

The space in the middle is the same due to the ….?

These bases re held together by …?

A

Bases projecting inwards
Hydrogen bonds- gives them strength
3 between C and G
2 between A and T

77
Q

DNA semi-conservative replication process ?

A

cell undergoes mitosis- a phase DNA replication
2 copies produced
1) DNA helicase breaks he hydrogen bonds and unwinds the double helix
2) this exposes the bases (DNA codes)
3) free DNA nucleotides bind to complementary bases
4) DNA polymerase links them by forming phosphate diesther bonds with nucleotides
5) seals the backbone- happens on both parent strands

78
Q

Why is it called semi-conservative DNA ?

A

2 copies are produced
One is parent original strand one is newly synthesised strand
Parent one provides template

79
Q

Mendeleev and stahl experiment

14N

A
N 14 is higher 
Centrifugation- spin tubes round
Force- heavier atom are pulled downwards/ lighter atoms go to top
Limitations
Sugar- same concentration
Spin same speed
Spin for same amount of time
80
Q

DNA molecules are very long as?

A

Hold a lot of information - form of DNA codes
Double helix structure provides stability
Hydrogen bonds allow for easy unzippig

81
Q

RNA is different to DNA ?

A

Riboxynucleic acids
Base is uracil
3 forms of RNA

82
Q

Steps of mRNA copying the DNA?

A

Sequences of bases in DNA > amino acids > proteins
1) DNA nucleotide sequence that codes for a particular protein can be exposed by splitting of hydrogen bonds and DNA helicase
2) RNA nucleotides copy the exposed sequences/gene (multiple sequences of nucleotides) to form a complementary strand- complementary base-pairing=mRNA
3) mRNA leaves nuclear complex via nuclear pore and attaches to a ribosome on the rough e.r
4) rRNA reads the mRNA 3 bases at a time (translation- 3 nueotides=1 amino acids)
5) tRNA (transfer RNA) brings the amino acids in that order to ribosomes
Peptide bonds are formed to make polypeptides and proteins)

83
Q

Gene is?

A

DNA sequence (multiple nucleotides) for coding for a polypeptide

84
Q

What are enzymes?

What do they have in common?

A

Globular proteins/soluble/catalyse metabolic reactions/catalysts

85
Q

What does a catalyst mean?

A

speeds up rate of reaction without undergoing any permanat change itself

86
Q

Exracellular or?

A

At outside cells

Intercellular (act inside cells)

87
Q

Enzymes have an active site which is?

A

Cleft which a substrate molecule will fit into complementary shape

88
Q

Lock and key> induced lock and key

A

Substrate (key) fits into the active site (lock)
Induced fit- active site changes shape to fit closer round substrate when they collide/oppositely charged groups also make it hold
Change destabilises substrate molecule- easier for reaction to happen

89
Q

Enzyme-substrate complexes ?

A

Different shape to active site so move out

90
Q

How do enzymes reduce activation energy?

A

Hold the enzymes in a way that makes it easier for reactions to happen-sufficent
Lower temp

91
Q

How does heat effect enzymes?

A

Intially increases rate of reaction- increased number of collisions- more with sufficent energy
Optimum temp
After rate decreases as kinetic energy makes bonds vibrate- break hydrogen/ ionic which hold tertiary struxure - unravels- active site chanea shape

92
Q

Why would the rate of reaction go to 0 if keep increasing temp?

A

Eventually enough bonds break 3d struxure unravels denaturation enzyme stops working

93
Q

Enzymes affected by pH?

What is pH?

A

Measure of H+ concentration
Negatively charged amino acid are attracted to H+ ions
Intiially rate of reaction increases - cluster round the amino acids- makes the substrate fit better
7 - optum pH- bet complementary shape
Increase it past 7 starts to decrease as active site changes shape- doesn’t got as well- lead to denaturation

94
Q

Increasing substrate conc?

A

More substrate molecules - more for active site to catalyse- more enzyme-substrate complexes formed
Plateau /level off- if all active sites are being occupied- doesn’t do anything
Enzyme concentration has to be fixed

95
Q

Increasing enzyme conc?

A

Intitily increases - more available- more complexes being formed
Plateau off- all substrate molecules are being catalysed at a fastest rate as possible
Substrate conc has to be fixed

96
Q

In both these enzyme and substrate concentrations are ?

Enzyme conc in cells are usually?

A

Limiting factors

Marinated at low level

97
Q

Competitive inhibitors are?

A

Inhibiton = decrease the rate of an enzyme-controlled reaction
Competitive- similar shape to substrate so can bind to active site- reduce no of complexes- produce enzyme-inhibitor complexes
If increase substrate conc- substrate more likely to bind- better fit but if increase inhibiton level more likely to bind more chance in collisions
Temporary bind to active site or permanently bind

Te

98
Q

Non- competitive inhibitors ?

A

Bind to other place away from acitve site - alter tertiary 3D shape- change active site shape so substrate doesn’t it in anymore- reduces complexes
Increasing inhibition increases decreases rate if reaction further
Increasing substrate conc doesn’t do anything as it doesn’t bind to active site
Temporary or permanent

99
Q

What are coenzymes?

A
Organic non-protein molecules
Bind same time or just before substrate
Recycled back to help with reaction
Carry chemical groups between enzymes in a sequence 
Eg coenzyme A- aerobic respiration
100
Q

Prosthetic groups?

A

Permanent coenzyme
Interfere with tertiary 3D shape so vital to function > properties
Eg haemoglobin

101
Q

Cofactors?

A

Inorganic ions
Combine with enzyme or substrate to change chars distribution or shape of enzyme-substrate compexes to make form easier
Eg amylose enzyme starch>maltose only if cl- ions are present

102
Q

Metabolic poisons- inhibitors?

A

Potassium cyanide
Inhibit cell respiration- inhibs enzyme cytochrome oxidase in mitochondria
Build-up of lactic acid in blood- cause people to die

103
Q

Medicinal drugs-HIV?

A

HIV needs protease enzymes to build new viral coats- reproduce
Protease enzymes acts as inhibitors to viral protease enzymes so stop them producing complexes- can’t reproduce

104
Q

Antibiotics- inhibitors?

A

Pencilin
Bacteria-cause infection
Bacterial enzyme forms cross-links in cell walls- cell walls are made of polysaccharide materials/cross-links provide support
Penicillin-similar to bacterial enzyme- fits in cell wall- slightly different so makes it weak>falls apart- bacteria can’t reproduce- competitive?

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