last minute things i need to remember Flashcards
describe the process of selective reabsorption of glucose and amino acids. (4)
sodium actively pumped out of cells lining tubule
conc of sodium decreases creating conc gradient
sodium diffuses into cell through cotransport protein carrying glucose and amino acids
water follows
how is water transported into a plant at the roots? (4)
ions actively transported into root tip, lowering it wp
water moves in by osmosis, moves along root apoplast and symplast pathway.
at endodermis, casparian strip forces water through symplast pathway into xylem
active transport of ions into xylem creates gradient for water to move in by osmosis
how do you adjust the concentration of ADH in the blood? (4)
osmoreceptors in hypothalamus lose water + shrink when wp is low
stimulates neurosecretory cells to make ADH in cell body,
and transports this to posterior pituitary gland
where ADH is stored in vesicles and released by exocytosis
what happens when adh is detected?
adh detected by cell surface receptors
enzyme controlled reactions
vesicles containing aquaporins move and fuse with membrane
more water can be reabsorbed
what is the “electrolyte” problem that arises from kidney failure?
kidney failure can cause abnormally high/low levels of electrolytes bc either none get reabsorbed or all stay in blood
urine samples in diagnostic
tests, with reference to the use of monoclonal
antibodies in pregnancy testing
blue bead is in end of pregnancy stick, and on that bead are antibodies for HCG
HCG binds to bead
bead moves, and goes past an area of fixed antibodies
that are complimentary to HCG
if youre pregnant, the HCG that has already bound to the bead will also attach to the fixed antibodies
how is insulin released from a beta cell
k+ channels are normally open so K+ flow out
when blood glucose conc increases, glucose moves in
and is metabolised to produce ATP
which closes K+ channels
so k+ accumulates inside, altering potential difference
which opens calcium channels
calcium floods in causing the vesicles of insulin to move and fuse with the membrane, releasing insulin by exocytosis
what are the 3 ways in which the hypothalamus coordinates the fight or flight response?
1) activates sns activates smooth muscle muscles and glands
2) activates sns adrenal medulla which secretes adrenaline
3) secretes CRH causing pituitary glad to secrete ACTH causing the adrenal cortex to secrete corticoid hormones
when insulin binds to a csr, what is the enzyme activated by the G protein?
tyrosine kinase
when adrenaline binds to a csr, what is the enzyme activated by the G protein?
adenyl cyclase
how the heart rate controlled, and by which two nerves?
accelerans nerve- noradrenaline- increase heart rate
vagus nerve- acetylcholine- decrease heart rate
describe the mechanism of muscle contraction
when the action potential reaches the sarcolemma, the wave of depolrisation goes down transverse tubules
which conduct the ap to the sarcoplasmic reticulum
which opens voltage gated calcium channels on the sarcoplasmic reticulum, releasing calcium
which binds to the troponin causing a confirmational change in the tropomyosin shape
exposing myosin binding sites on actin, myosin heads bind
ATP binds to myosin head, causing it to bend in the power stroke
which slides the fillament along
ATP is broken into ADP+pi
head detaches
where does the light dependant stage (cyclic and non-cyclic photophosphorylation) occur in photosynthesis?
light dependent- thylakoid membrane
light independent- stroma
name and describe the fermatation pathway used in anaerobic respiration in mammels
lactate fermentation pathway
- rNAD is oxidised to NAD releasing 2 hydrogens
- these hydrogens combine with pyruvate and lactate dehydrogenase to produce lactate
name and describe the fermatation pathway used in anaerobic respiration in yeast
ethanol fermentation pathway
- pyruvate is decarboxylated using pyruvate decarboxylase releasing co2, producing ETHANAL
- rNAD is oxidised to NAD releasing 2 hydrogens
- these hydrogens combine with ETHANAL and ETHANOL dehydrogenase to produce ethanol
