Biology (Biological molecules) Flashcards
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
Properties of triglycerides?
soluboltiy?
energy strorage?
thermal insuakltion?
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
phosloipids are amde up of?
2 fatty acids+ 1glycerol + 1 phosphate group
27
why is the phospate 'head' hdrophilic?
attratced to water moeciles
| 0 has delta negative charge on it- attratced to dleta positive charge on hydogen atoms inw ater molecules
28
fatty acid tails are?
hydrohobic- inner bit of membrane- repel water while hydorphilic heads stay ont he outside of membranes close to wtaer
29
phoislipids make up the?
bilayer (membrane)- seprate cell contents/les substances diffuse in/ cell signalling
30
fatty acids may be?
| cold climates
unsaturated- membrane is mroe fluid- in colder climates- this is ideal in low temps
saturated- more solid- less flexible
31
Animals in colder climates have?
thick layer so adipose tissue (triglycerides)storage moleules- store vitamin A and D
32
phos[ahes can ahve carbohydrate?
chains attached to them- cell signalling
33
Choeleterol is a ?
diffusion
fludiity
lipid hormone
- dissuse starght thorugh bilayer though simple diffusion
- sits in between fatty acid tails>stabiltiy
34
hgih levels of Cholesterol means?
bile
inner linigns?
lumps.gallstones
| innerlinings>desposits>atherclesosis
35
Proteins are ..... joined together yb thousands of?
polymers
| monomers- amino acids
36
strucure of amino acid has R group..?
differnt for every amino acid
| 20 of them- each amino acid in chain- possiblity out of 20
37
amino acid in plants?
maunfacure them from niortates in soil
38
essenail amino acids for animals?
| vegetarians- protein source?
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
What happenms if too many amino acids
toxic- have to be remvoe dby deanimation
40
protein is?
one or more polypeptide chains joined together
41
called amino acid residue as?
enzymes?
ezymes that break down protien are?
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
proteins/polypetides aresyntheised on?
ribosomes-deterined by mRNA orders the amino acids in a partiuclar sequence
differne protiens- differnt mRNA has to pas throgh ribosomes
43
pimary strucure is?
basic sequnce of amino acids
44
seocndary strucure is?
```
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
tertiary strucuture is?
| vital to funciton?
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
```
Bonds in tertiary strucure?
disulfide
ionic
hydrogen
hydrophilic/hydrophobic interactions?
```
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
Ehat happens if hea is appleid to tertiayr structre?
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
Quaternary strcuure is?
protien with more than one polypeptide chain or a one and an inorgainc component
49
haemoglobin has quaternary strcure
subuntis (chains)
prosthtic group
```
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
How ia the atrcuure of ahempglobin adapete dto its function
| 3D tertiary shape- carry oxygen to tissues
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
Collagen is a ..... protein so is......in water?
fiborous protein- strucural roles- insoluble inw water
52
Collagen is made up of?
popypptide chains
left-handed alpha helix?
amino acids?
3 poplypetide chains wound in a left-handed helix strucure (makes it more fiborous)
35% of glycine, proline, alaline
53
How does the strucute of collagen adaopt it to its function?
hydrogen bonds?
covalent bonds
cross-links
hydrogen bonds wihthing heli strucure- strength
collagen molecuels form cross-links with neighbouring ones addign strenght/stabiltiy
cross-links are staggered- adding strength
54
What is collagen's role in body?
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
Starch test?
add iodine
| changes form yellow/brown to blue/black
56
reducing sugars test?
colourimeter?
calibration curve?
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
non-reducing sugar test?
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
lipids test?
dissolve in ethanol
| shake it with ethanol>decant into test-tube>cloudy white emulsion
59
proetins test?
biruet reagent
add it in equal voume to sample>down side of test-tube
blue ring>dissolve to violet colour
60
water is polar so?
electron density
hydrogen bonds making/breaking
unssymetircal electorn density
| continaulyl maing/brekaing hydroge bonds- moving around
61
What does the strong hydrogen bonds mean in relation to keep large bodies of water stable?
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
What does hdogen bonds mena in terms of freezing?
| ice?
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
What does evaporation from surface of water do
| humans?
cools it- keep temp constant
| humans- sweating/dogs- panting
64
cohesion forces due to hydoregn bonds mean?
| plants?
stick toger-pulled pu as pne continous colum
| xylem vessles.used to trrasnprot water up plant
65
wate provides a medium like?
blood (humans) and vascualr tissue (plants)
66
as water is polar when polar molecules ..?
| metbaolc processes?
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
Nucleotides are?
Monomers of nucleic acids
| DNA = deoxyribonucleic acid
68
Components of nucleotides are?
Phosphate group
5-carbon sugar
Nitrogenous bases
69
Condensation reactions?
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
As nucleotides are bonded together?
Repeating sugar-phosphate backbone with bases projecting inwards
Sequence of bases that provide the coded information in DNA
71
Only sugars that are?
The same bind together so nuclei acids can only be DNA or RNA
72
DNA is?
Double stranded
Purines- adenine which matches to pyrimidine thymine
Purine- guanine which matches to pyrimidine cytosine
73
RNA is?
Single-stranded
Purine- adenine matching with pyrimidine uracil
Purine- guanine matching with pyrimidine cytosine
74
In DNA the two strands?
Coil together to form a double helix
75
Thy are said to be anti?
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
The space in the middle is the same due to the ....?
| These bases re held together by ...?
Bases projecting inwards
Hydrogen bonds- gives them strength
3 between C and G
2 between A and T
77
DNA semi-conservative replication process ?
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
Why is it called semi-conservative DNA ?
2 copies are produced
One is parent original strand one is newly synthesised strand
Parent one provides template
79
Mendeleev and stahl experiment
| 14N
```
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
DNA molecules are very long as?
Hold a lot of information - form of DNA codes
Double helix structure provides stability
Hydrogen bonds allow for easy unzippig
81
RNA is different to DNA ?
Riboxynucleic acids
Base is uracil
3 forms of RNA
82
Steps of mRNA copying the DNA?
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
Gene is?
DNA sequence (multiple nucleotides) for coding for a polypeptide
84
What are enzymes?
| What do they have in common?
Globular proteins/soluble/catalyse metabolic reactions/catalysts
85
What does a catalyst mean?
speeds up rate of reaction without undergoing any permanat change itself
86
Exracellular or?
At outside cells
| Intercellular (act inside cells)
87
Enzymes have an active site which is?
Cleft which a substrate molecule will fit into complementary shape
88
Lock and key> induced lock and key
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
Enzyme-substrate complexes ?
Different shape to active site so move out
90
How do enzymes reduce activation energy?
Hold the enzymes in a way that makes it easier for reactions to happen-sufficent
Lower temp
91
How does heat effect enzymes?
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
Why would the rate of reaction go to 0 if keep increasing temp?
Eventually enough bonds break 3d struxure unravels denaturation enzyme stops working
93
Enzymes affected by pH?
| What is pH?
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
Increasing substrate conc?
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
Increasing enzyme conc?
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
In both these enzyme and substrate concentrations are ?
| Enzyme conc in cells are usually?
Limiting factors
| Marinated at low level
97
Competitive inhibitors are?
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
Non- competitive inhibitors ?
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
What are coenzymes?
```
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
Prosthetic groups?
Permanent coenzyme
Interfere with tertiary 3D shape so vital to function > properties
Eg haemoglobin
101
Cofactors?
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
Metabolic poisons- inhibitors?
Potassium cyanide
Inhibit cell respiration- inhibs enzyme cytochrome oxidase in mitochondria
Build-up of lactic acid in blood- cause people to die
103
Medicinal drugs-HIV?
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
Antibiotics- inhibitors?
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?
