principles biochemistry Flashcards
what is glucose
monosaccharide carbohydrate
examples of disaccharides
maltose, sucrose, lactose
examples of poysacharides
cellulose and glycogen
examples of sugars
mono and disacharides
what happens in aerobic glycolysis
glucose is oxidised and 2 pyruvate are produced in the cytosol
net gains of aerobic glycolysis
2ATP invested , 4 produced, 2NAD -> 2NADH + 2H
final electron acceptor of aerobic glycolysis
NAD
regulation of aerobic glycolysis
hexokinase, phosphofructokinase, pyruvate kinase, citrate
stiochemetry of anaerobic glycolysis
pyruvate + NADH -> lactate + NAD
what is the warburg effect
cancer cells have high anaerobic glycolysis rate and low hexokinase
storage of glucose
glycogen, starch, sucrose or converted to lipids
what produces ribose-5-phosphate
oxidation through the pentose phosphate pathway
glucose transporter
GLUT Na/glucose symporters - passive diffusion
aerobic respiration
glycolysis, TCA cycle, electron transport chain
what are amphipathic molecules
hydrophobic and hydrophilic and form michelles in water
what are zwitteriins
amino acids without charged side groups in nuetral solutions/isoelectric points
what is the function of a buffer
since both ends can be ionised, control pH in blood
example of a buffer
haemoglobin
primary structure
sequence of amino acid residues
secondary structure
hydrogen bonding of polypeptide chain eg alpha helix, beta sheet, triple helix
tertiary structure
3D metal ion complexes, disulfide bone, hydrogen bonding
quartenary structure
arrangement of different polypeptide subunits in a protein
fibrous protein
polypeptide chains in parallel, strong insoluble eg keratin, collagen
globular protein
spherical soluble since polar chains are on the outide eg heamoglobin and myoglobin
cofactor
metal ions, metal cooridination centre in the enzyme - effect the activity of enzymes
metalloprotein
enzyme with metal coordinations in its centre
coenzyme
necessary for enzyme function
apoenzyme
cofactor
holoenzyme
enzyme + cofactor
isozymes
isoform of enzyme, catalyse same reaction but different chemical properties
regulation
by phosphorylation (kinase) or dephosphorylation (phosphotase) active/inactive form
zymogens
inactuve precursors of an enzyme, irreversibly changed to active enzymes by cleavage
proteolysis
enzyme regilation, proteins/[peptides broken into amino acids by enzymes such as trypsin
what does michaelis menten kinetic model explian
relationship between Vmax and Km and how substrate conc affects catalysis rate
what is vmax
the reaction rate at infinite substrate concentration
what is Km
substrate at 50% of reaction rate
low Km needs
little substrate to work at half max rate
lineweaver burke plot
for determination of vmax and Km uses reciprocals of V and S
vmax same Km varies
competitive inhibitor
vmax varies, km same
non competitive inhibitor
vmax on lineweaver burke plot
intersection with Y axis
Km on line weaver burke plot
intersection with x axis
allosteric control
end product inhibits rate limiting enzyme to avoid intermediate build up
allosteric enzyme
non michaelis menten kinetics, increase substrate concentration causes sigmoid curve not hyperbola fue to cooperativity
oxygen to heamoglobin
allosteric regulation and positive cooperativity
stoichestry of TCA cycle
pyruvate -> acetyl - coA +NADH +H
what is the TCA cycle catalysed by
pyruvate dehydrogenase
where does the TCA cycle take place
mitochondrial matrix
ATP of TCA cycle
2 ATP
stages of TCA
uptake of C (acetyl coA)
release of 2C as 2CO2
transfer of 3 pairs of electrons from NAD to 3NADH+H
transfer of one pair of electrons to reduces FAD -> FADH2 by succinate dehydrogenase
1 GTP formed from GDP +Pi
what is the only enzyme in the mitochondiral membrane not the matric
succinate dehydrogenase
what is PDC deficiency disorder
X linked disorder causes still births in males
what does NADH do
delivers electrons to the lectorn transfer chain in the inner mitochondrial membrane _> phosphryl trasfer potential for ATP hydrolysis
what happens when NAD is regenerated
retuned to glycolysis
what inhibits oxidative phosphorylation
cyanide, azide and CO
how much ATP generated by the end of TCA
32
what does insulin do
activates glucose in blood for glycolysis, glycogen synthesis, protein synthesis and ion uptake
insulin defiency
no cellular glucose uptake so increased blood glucose some glucose in urine / diuresis which presents as dehydration and the body breaks down fts for fuel into fatty acids and acidic ketone bodies so presents as ketoacidosis
what are lipids
long chain fatty acids
what is lypolysis
lipid breakdown, fat stored in adipose tissue
what is glycogen
glucose residues stuck together
glycoenolysis
glycogen breakdown
glycogen storage disease
cant break down glycogen, glucose not released from glycogen storage when required (exercise), glycogen acculumarte causing hepatomegaly
what is cholesterol used for
memvrane structure and fluidity bile ducts, vit and steriod hormones precursor
what do lipoproetins do
carry lipids in blood
what is a case control study
2 groups compared on the basis of a supposed attribute
what is a cohort study
follows a group of people over time - eg risk factors for a disease
what is systemic review
literature review focused on a research question, syntheize high quality evidnce
what is meta analysis
combines findigs from independent studies
