principles biochemistry

Question 1

what is glucose

Answer 1

monosaccharide carbohydrate

Question 2

examples of disaccharides

Answer 2

maltose, sucrose, lactose

Question 3

examples of poysacharides

Answer 3

cellulose and glycogen

Question 4

examples of sugars

Answer 4

mono and disacharides

Question 5

what happens in aerobic glycolysis

Answer 5

glucose is oxidised and 2 pyruvate are produced in the cytosol

Question 6

net gains of aerobic glycolysis

Answer 6

2ATP invested , 4 produced, 2NAD -> 2NADH + 2H

Question 7

final electron acceptor of aerobic glycolysis

Answer 7

NAD

Question 8

regulation of aerobic glycolysis

Answer 8

hexokinase, phosphofructokinase, pyruvate kinase, citrate

Question 9

stiochemetry of anaerobic glycolysis

Answer 9

pyruvate + NADH -> lactate + NAD

Question 10

what is the warburg effect

Answer 10

cancer cells have high anaerobic glycolysis rate and low hexokinase

Question 11

storage of glucose

Answer 11

glycogen, starch, sucrose or converted to lipids

Question 12

what produces ribose-5-phosphate

Answer 12

oxidation through the pentose phosphate pathway

Question 13

glucose transporter

Answer 13

GLUT Na/glucose symporters - passive diffusion

Question 14

aerobic respiration

Answer 14

glycolysis, TCA cycle, electron transport chain

Question 15

what are amphipathic molecules

Answer 15

hydrophobic and hydrophilic and form michelles in water

Question 16

what are zwitteriins

Answer 16

amino acids without charged side groups in nuetral solutions/isoelectric points

Question 17

what is the function of a buffer

Answer 17

since both ends can be ionised, control pH in blood

Question 18

example of a buffer

Answer 18

haemoglobin

Question 19

primary structure

Answer 19

sequence of amino acid residues

Question 20

secondary structure

Answer 20

hydrogen bonding of polypeptide chain eg alpha helix, beta sheet, triple helix

Question 21

tertiary structure

Answer 21

3D metal ion complexes, disulfide bone, hydrogen bonding

Question 22

quartenary structure

Answer 22

arrangement of different polypeptide subunits in a protein

Question 23

fibrous protein

Answer 23

polypeptide chains in parallel, strong insoluble eg keratin, collagen

Question 24

globular protein

Answer 24

spherical soluble since polar chains are on the outide eg heamoglobin and myoglobin

Question 25

cofactor

Answer 25

metal ions, metal cooridination centre in the enzyme - effect the activity of enzymes

Question 26

metalloprotein

Answer 26

enzyme with metal coordinations in its centre

Question 27

coenzyme

Answer 27

necessary for enzyme function

Question 28

apoenzyme

Answer 28

cofactor

Question 29

holoenzyme

Answer 29

enzyme + cofactor

Question 30

isozymes

Answer 30

isoform of enzyme, catalyse same reaction but different chemical properties

Question 31

regulation

Answer 31

by phosphorylation (kinase) or dephosphorylation (phosphotase) active/inactive form

Question 32

zymogens

Answer 32

inactuve precursors of an enzyme, irreversibly changed to active enzymes by cleavage

Question 33

proteolysis

Answer 33

enzyme regilation, proteins/[peptides broken into amino acids by enzymes such as trypsin

Question 34

what does michaelis menten kinetic model explian

Answer 34

relationship between Vmax and Km and how substrate conc affects catalysis rate

Question 35

what is vmax

Answer 35

the reaction rate at infinite substrate concentration

Question 36

what is Km

Answer 36

substrate at 50% of reaction rate

Question 37

low Km needs

Answer 37

little substrate to work at half max rate

Question 38

lineweaver burke plot

Answer 38

for determination of vmax and Km uses reciprocals of V and S

Question 39

vmax same Km varies

Answer 39

competitive inhibitor

Question 40

vmax varies, km same

Answer 40

non competitive inhibitor

Question 41

vmax on lineweaver burke plot

Answer 41

intersection with Y axis

Question 42

Km on line weaver burke plot

Answer 42

intersection with x axis

Question 43

allosteric control

Answer 43

end product inhibits rate limiting enzyme to avoid intermediate build up

Question 44

allosteric enzyme

Answer 44

non michaelis menten kinetics, increase substrate concentration causes sigmoid curve not hyperbola fue to cooperativity

Question 45

oxygen to heamoglobin

Answer 45

allosteric regulation and positive cooperativity

Question 46

stoichestry of TCA cycle

Answer 46

pyruvate -> acetyl - coA +NADH +H

Question 47

what is the TCA cycle catalysed by

Answer 47

pyruvate dehydrogenase

Question 48

where does the TCA cycle take place

Answer 48

mitochondrial matrix

Question 49

ATP of TCA cycle

Answer 49

2 ATP

Question 50

stages of TCA

Answer 50

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

Question 51

what is the only enzyme in the mitochondiral membrane not the matric

Answer 51

succinate dehydrogenase

Question 52

what is PDC deficiency disorder

Answer 52

X linked disorder causes still births in males

Question 53

what does NADH do

Answer 53

delivers electrons to the lectorn transfer chain in the inner mitochondrial membrane _> phosphryl trasfer potential for ATP hydrolysis

Question 54

what happens when NAD is regenerated

Answer 54

retuned to glycolysis

Question 55

what inhibits oxidative phosphorylation

Answer 55

cyanide, azide and CO

Question 56

how much ATP generated by the end of TCA

Answer 56

32

Question 57

what does insulin do

Answer 57

activates glucose in blood for glycolysis, glycogen synthesis, protein synthesis and ion uptake

Question 58

insulin defiency

Answer 58

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

Question 59

what are lipids

Answer 59

long chain fatty acids

Question 60

what is lypolysis

Answer 60

lipid breakdown, fat stored in adipose tissue

Question 61

what is glycogen

Answer 61

glucose residues stuck together

Question 62

glycoenolysis

Answer 62

glycogen breakdown

Question 63

glycogen storage disease

Answer 63

cant break down glycogen, glucose not released from glycogen storage when required (exercise), glycogen acculumarte causing hepatomegaly

Question 64

what is cholesterol used for

Answer 64

memvrane structure and fluidity bile ducts, vit and steriod hormones precursor

Question 65

what do lipoproetins do

Answer 65

carry lipids in blood

Question 66

what is a case control study

Answer 66

2 groups compared on the basis of a supposed attribute

Question 67

what is a cohort study

Answer 67

follows a group of people over time - eg risk factors for a disease

Question 68

what is systemic review

Answer 68

literature review focused on a research question, syntheize high quality evidnce

Question 69

what is meta analysis

Answer 69

combines findigs from independent studies