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72 Cards in this Set
- Front
- Back
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characteristics of active site? |
- it is the side chains and subtrates interaction - bind to substrate with weak force |
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what is the geospecificity and stereospecificity |
GEO- particular shape itself that fit into the active site
stereo- the erientation that allows the reaction to occur. |
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lock in key by whom indced fit by whom |
fiscer koshland |
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acid and base catalysis |
- H+ transfer - Glu, Asp, Lys |
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which amino acid involve in acid and base cataysis |
histidine |
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covalent catalysis |
formation of a highly reactive, short lived intermediate |
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metal ion catalysis |
- about a third require this - coenzyme (subset of co factor) |
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what use Mg 2+ as a cofactor |
hexokinase |
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list the enzymes 1. iron 2. copper 3. magnesium |
1. cytochrome oxidase catalase, peroxidase 2. cytochrome oxidase 3. carbonic anhydrase and alcohol dehydrogenase 4. lexokinase, glucose-6 phosphatase, pyruvate kinase
CCP, copper C, zn Ca, HGP |
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1. co enzymes thaimine pyrophophate 2. FAD 3. NAD |
1. aldehydes , B1 2. electrons B2 3. hydride ion, niacin, nicotinic acid |
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NAD participate in redox |
alcohol dehydrogenase ethanol to acetaldehyde |
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oxireductase transferase hydrolase lyases isomerase ligase |
- transfer electron - group transfer - hydrolases reaction - addition of double bond - yield isomeric form - formation of c-O, C-S, C-C and C-N condensation |
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what are the 4 assumptions |
- no product present - conc- substrate greater than enzymes - initial substarte conc does not change significantly - formation and breakdown in a fast equilibrium
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2 ways of calculating Km |
1. substrate conc at half Vmax 2. K-1/K1 Es breakdown/ES formed |
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how do you calculate enzyme efficiency |
Kcat/Km |
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define Kcat using formula |
Vmax/total enzyme conc catalytic rate constant |
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what Ki gives a strong binding |
10^-9 |
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define Kcat |
how much substrate is converted to product per enzyme per unit time |
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what is gout results from |
uric acid |
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what convert xanthine to uric acid |
xanthine oxidase |
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what is GABA degraded by and what is the inhibitor for this enzyme |
gaba aminotransferase anti-covulsant |
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HIV reverse transcriptase protease competitive or non competitve? |
azt- competitive, nevirapine- non competitve - all competitve |
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what does the meta ion provide |
- right orientation - binding energy - site for oxudation reduction reactions |
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coenzyme |
- are small organic molecules - co substrates - function as carriers - often derived from vitamins |
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example of irreversible enzymes penicillin oranophosphates |
- penicillin- inhibitor of glycopeptide transpeptidase in bacteria cell wall - cause paralysis by inhibiting acetycholinesterase |
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what is Ki |
Ki= E times I/EI |
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examples of allosteric effectos |
enzymes aspartate transcarbarnoylase CTP inhibit enzymes ATP activates enzymes |
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how is zymogen activated? |
activated by snipping out two dipeptides to from cymotrypsin change in conforamtional change |
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isoenzymes |
differ in physical, kinetic and immunological properties but catalysing the same reaction
and arise from two different genes |
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phosphatecreatine + ADP--> CK --> ATP |
heart muscle CK-MM 7% CK MB- 30% due to myocardial infarction |
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what is seizures caused by? |
insufficient GABA |
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what is a copper containing oxidoreductase |
tyrosinase |
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catalyse the steps in what? |
biosynthesis of melanin from tyrosine |
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what is it called when brown pigment found in plants?
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polyphenoloxidase |
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oxidise dopamine to what? dopamine- catecholamine |
an ortho quinone |
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oxyhaemoglobin is deoxygenated by what? |
dithionite solution |
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each haemoglobin carries |
4 oxygen molecules and 8 oxygen atoms |
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colour of metHB and deoxyhaem |
- brown - dark red |
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oxydation oxygenation |
loss of electrons gain of lxygen |
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cell-type responsible for the synthesis of melanin in the epidermis |
melanocyte |
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phenomelanin |
red-coloured chromophore |
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kinase |
phosphorylate |
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cell type to which melanin is exported |
keratinocyte |
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dark brown pigment |
eumelanin |
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melanosomes |
tyrosinase is a trans-membrane protein of this |
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copper |
tyrosinase cofactor |
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post translational modification of tyrosinase |
glycosylation |
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melanocyte dendrites |
cellular extension |
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participate in the redox reaction associated with tyrosinase activity |
copper |
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activate tyrosinase |
phosphorylation |
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pathway that synthesis malaninn |
melanogenesis |
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melanocyte stimulating hormone |
stimulates melanogenesis |
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melanocortin 1 receptor |
melanocyte stimulating hormone binds to this |
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what promote the release of MSH |
ultra violet radiation |
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froma s protective cap around the nucleus |
melanin |
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can absorb ultraviolet light |
melanin |
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often mutated in red headed |
MC1R |
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may be useful for pharmacologically inducing tanning exposure |
MSH analogues |
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can correct UV induced thymine dimers |
dna repair systems |
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difficult to determined because... |
is only approaching asymptote |
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what are the two types of macromolecule that can catalyse reacton |
ribosome and proteins |
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which features distinguish ensymes from chemical catalysts |
specificity, tightly regulated, milder reaction conditio, fast reaction rate |
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Km is also called dissociation constant |
K-1/K1 |
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the inactived form of ensyme are actvated by proteolysis |
oh ok |
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name two types of PTM that can activate ensymes |
phosphrylation and proteolytc cleavage |
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allosteric inhibiton |
reduce the activity of an ensyme but shouldn't inactivate it completely |
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lineweaver burk plot is taking the reciprocal |
oh ok |
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Kcat is |
Vmax/Et |
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what does penecillin bind to |
glycopeptide transpeptidase, irreversible |
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anchoring ensyme |
membrane spanning alpha helix holds the blood cel protein in the membrane and alternatively hydrophobic domain cannsert into the lipid interior or the membrane and locate a periheral protein on the membrane surface, poast translational addition of lipids. |
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how is lipid bilayer made and maintained |
terminal signal sequence of amino acids directs proteins t the ER, inserting protein into the lipid bilayer. once inserted into the lipid layer the protein is then transported to its final destination in vesicles. as its destination the vesicle carrying the membrane protein duses with the target membrane. during vesicle transport sugars are often added to the region of the protein that will be facing the cell exterior. thus protein facing outside the membrane have sugar attached |
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difference between ionotropic and metabotropic |
ion: directly open the channel and direct conformational change
meta: like g couple protein requires second messengers to signal |
