Hormonal communication Flashcards
w/ ref, describe the events occurring at the stages labelled 1 to 4
1) glucose metabolised to produce ATP
2) ATP blocks potassium ions + k+ builds up inside cells
3) VG Ca2+ channels opeen to Ca2+enter by diffusion
4) more Ca2+ resulting in exocytosis
after the inital release of insulin from the beta cell, insulin secretion continues even when there is no further glucose intake
suggest and explain why the cell continues to secrete insulin
- continues to be secrete as long as blood glucose conc remains high
- ATP is still present + so K+ channels remain closed
- exocytosis still being trigged by Ca2+
describe 2 similarities in the action of plant and animal hormones in cell signalling
- hormone binds to receptor
- causing cascade of events / enzymes reactions
- may involve switching on/off genes
- only needed in small conc to have an effect
- may have effect on more than one target tissue
- that effect may involve interaction of more than one hormone
explain why plants are more able to form natural reproductive clones than animals
- most plant cells retain the ability to differenciate (totipotent)
- plant have meristems
- plant cells can de-differenciate +then differenciate into a diff cell type
- mosy animal cells are not totipotent/ are multipotent
- hybrids cannot reproduce sexually
- polypoidy provide dupilcate of each chromosomes
- polyploidy allows the hybrid to form gametes
cross seedling
cross seedling
- apex(tip of shoot) produce auxin
- diffuse down shoot
- greater auxin conc on shaded sided of stem
- auxin causes cell wall loosening
- auxin causes cell elongation
- H+ ions pumped into cell wall/ decr pH to allow
- enzymes to work/ bonds broken within cellulose in walls
human
- AP along sensory neurone membrane
- synpase across neuromuscular junction
- Cu2+ inside presynaptic transmission + this causes vesicles containing ACH to move + fuse w/ plasma membrane, leaving into synaptic cleft
- depolarisation of muscle fibres (ACH bind to receptor of sarcolemma)
-actin+myosin slide over each other
why is it important that the patient had not eaten for at least eight hours before the blood glucose conc test
time needed to restore normal glucose conc
- HBAIC contained within erythrocytes
- RBC have a limited life span
- HBA1C broken down in liver
-patient might have has a drink containing sugar
- patient was nervous+ secreted adrenaline
- other medication interferes w/ glucose levels
- if blood glucose falls extremely low
-if patient cannot produce enough glucagon - glucose source cannot be taken by mouth
describe how glucagon is invloved in the regulation of blood glucose conc in a person who is able to regulate their blood gluocse conc correctly
- glucagon released by alpha cells in islet of langerhans in the pancreas
- promotoes conversion of gycogen to glucose in liver cells
- gluconeogenesis
- conversion of triglcerides to fatty acids
- negative feedback reduces the secretion of glucagon
- glucagon reduced insulin secretion
name the endocrine tissue in the pancreas that is responsible for secretion of hormones
islets of langerhans
identify the specific cell type in pancreatic tissue that secretes the hormone insulin
beta cells
- increases
- glycolysis
- depolarised
- calcium
- exocytosis
state where in a pancreatic cell insulin molecules are synthesised
ribosomes
outline the events that occur after the synthesis of an insulin molecule until it is reading to be secreted from the pancreatic cell
- transported to golgi
- modified in golgi
- packaged into vesicles
- vesicles transported towards plasma membrane
explain what is meant by homeostasis
maintain a stable internal environment despite changes in the external environment
describe how negative feedback is used to control blod glucose conc
when BGC increase, beta cells in the islets of langergans in the pancreas detect this + release insulin. this allows uptake of glucose in the liver cell. this increases conversion of glucose into glycogen. This increases rate of respiration to release energy.
when BGC decrease, alpha cells in the islets of langerhans in the pancreas release glucagon. this increase the coversion of glycogen into glucose. glycogenolysis. this increase the making of new glucose from amino acids/ gluconeogenesis. glucose leaves cells by facilitated diffusion into blood.
explain how emphysema could result in fatigue
- lesss ventilation
- less oxygen for respiration
- so less ATP produced
- increased acidity as CO2 interfering w/ enzymes
suggest why fatigue may occur in a person w/ type 2 diabettes who is not taking medication
- less glucose uptake into cells
- less glucose for respiration
- glucose not converted to glycogen
suggest how weak + irreglular heart beat could result in fatigue
- slow rate of blood flow
- less oxygen for aerobic respiration
- less glucose reaching cells for respiration
- so less ATP produced
- Increased acidity affects enzymes
outline the consequences of an ineffecient transfer in pyruvate into mitochondria + link this to the symptoms of CFS stated above.
- less pyruvate for krebs cycle
- no oxidative phosphorylation
- less ATP for muscle contraction
- anaerobic respiration takes place
- decrease pH causing aching muscle
suggest the poor specific immune response in ppl in CFS
- B lymphocytes dont respond to cytokines that have been produced
- little ATP for B cell mitosis
- little ATP for release of antibodies
state the name given to the groups of cells labelled x
islets of langerhans
describe the diff ways in which the pancreas acts as both an endocrine + an exocrine gland
endocrine
- hormone released directly into blood
- beta cells secrete insulin
- alpha cells secrete glugagon
- islets of langerhans monitor blood glucose conc
exocrine
- enzymes released in duct
- release triggered by nervous stimulation
- pancreatic secretions into small intestine
- alkaline
- containing lipid +amylae
B E D A G H C F J
state 2 advantages of treating type 1 diabetes by using insulin that has been produced by genetically modified bacteria rather than insulin that has beeen extracted by pigs
- plentiful supply
- cheap
- more ethical
- no religious objections
- reliable quantity
- exact match to human insulin
state an adv of using stem cells as a treatment for diabtetes 1 compared to treatment using insulin
- has the potential to cure the condition
- no need for repeated treatments (no need to inject insulin regularly)
i) cAMP, adrenaline
ii) glycogen into glucose by hydrolysis ; protein kinase attracts glygogen phosphoylase
suggest how the adrenaline molecule can cause different effects in diff target tissues
- diff tissues have diff receptors
- causing cAMP conc to increase or decrease
- second messenger may be different
- cAMP activates other enzymes in diff target cells
outline the hormonal+ nervous mechanisms involved in the control of heart rate
- adrenaline increases heart rate
- cardiovascular centre in medulla oblongata
- nervous connection to SAN
- which controls frequency of waves of excitation
- vagus nerve decreases heart rate
- accelerator nerve increases heart rate
- high blood pressure detected by baroreceptors
- low blood pH detected by chemoreceptors
- receptors in carotid arteries/ aorta
between starch + sucrose
- starch contains only glucose
- and sucrose contains 50% glucose
- by hydroylsis starch releases more glucose
between starch and cellulose
- both starch and cellulose are only made of glucose
- starch can be broken down but cellulose cannot be broken down
- enzyme present for starch digestion
w/ ref to table, explain how a person w/ type 2 diabetes could control the condition by modifiying their diet
- low starch
- as starch has the greatest effect on blood glucose conc
- increase protein/ cellulose has no effect on blood glucoe
- some sugars
- limiting fat as causes an imcrease in insulin + will make cells less responsive
glycogen: carbohydrate ; storage of glucose, provide glucose, undergo glycogenolysis ; liver cells
glucagon: hormone ; incr blood glucose conc, bind to receptor cells, causes conversion of glycogen to glucose ; islets of lamngerhans
name one hormone which increase the HR
adrenaline
state one way in which the nervous system decreases the HR
impulses along vagus nerve
RNA polymerase:
- makes mRNA
- transcription
- one strand DNA used
DNA polmerase
- DNA replication
- semi conservative/ both strands used
- used before cell division
Apoptosis
cytoskeleton
enzymes
phagocytosis
mitosis
tumour
describe how 2 internal organs would function differently in a calm mammal compared to a frightened mammal
lungs- breathing low- breathing fast
liver- glucose to glycogen - glycogen to glucose
heart - decr heart rate - incr heart rate
calm - parasympathetic - acetylcholine
frightened - sympathetic - noradrenaline
state precisely where in the body adrenaline is produced
adrenal medulla
adrenaline binds to receptors
complementary fit
G protein activated
adenyl cyclase activated
ATP converted to cAMP
cAMP activates proteins
by altering 3D structure/ phosphorylation
suggest how having a no. of steps in the signalling pathway enables a small no. of adrenaline molecules to rapidly cause large effects
- one molecule cause activation of many others
- this multiplying effect is repeated at every step
- recyling of cAMP
diff excretion -metablic waste , substances is to be removed from body ; urea, CO2, water
diff secretion useful product , substances are moved from within the body , remain in body ; enzymes insulin , antibodies
both require ATP, involved in homeostasis
glucose is not the only subtrate , fast can also be respired
ATP is produced by phosphorylation
other steps involved like krebs cycle
explain how type 1 diabetes is caused
- unable to produce insulin
- beta cells damaged
- by autoimmune disease
- family history
- condition can be triggered by environmental factor
describe 3 factors that increase a persons risk of developing type 2 diabetes
- lack of physical activity
- high intake of highly processed food
- increasing age
- more common in males
-more common in asian groups - obese
-high blood pressure
-excessive alcohol intake
iv: conc of GH injected
dv: rate of growth
cv: animal species , foodstuff, conditions
trial pop over several months
control group to ensure validity of conclusions
method for assessing growth :% mass change of growth rate to allow comparability , diff species of chicken should be investigated , ensure food is consistent across all trial groups
sample size needs to be large enough to reduce effect of anomalies
ethical concerns - chicken should be reared in human conditions
consideration of potential -ve effects on chickens: large muscle mass, so may be unable to move as easily
describe how adrenaline binds to cardiac cells
- binds to receptors in plasma membrane
- glycoprotein
no production of hCG until 4 weeks
rapid increase until 8 weeks
rate of decline is less than increase after 8 weeks
level peaks at 8 weeks
levels fluctuate after 19 weeks
levels remain similar after 19 weeks
- hCG is a peptide hormone
- hCG binds to cell surface receptor
- cell signalling is involved in action of hCG
- hCG uses cAMP to bring about response in cell
which molecule does oestrogen interact with when it changes cell activity
DNA
cells produce more hCG than normal
due to expression of genes
synthesising more hCG
other tissues could be stimulated to produce more hCG than normal
adrenaline - incr HR, incr BP, incr blood glucose conc
noradrenaline
glucocorticoids / cortisol
1st row : cortex ; reabsorption in kidneys, control of BP
2nd row: adrenaline
A ,B
K - islets of langerhans
L - blood vessel
w - liver/ hepatic
x - islets of langerhans/ pancreatic
y - skeletal muscle
name the cells that secrette insulin
beta cells ( in the islets on langehans in the pancreas)
explain why it was necessary to incr the conc of glucose surrounding the cells before they measured insulin secretion
- glucose conc causes release of insulin
- change in insulin secretion is high enough to be measured
suggest and explain which statistical test the researchers would have used to analyse their data
- unpaired t test
- bc they are comparing means
the statistical test gave a value of p < 0.001. use the words chance + probability to draw a conclusional fromt he result of the statistical test
- probability is less than 0.001
- so differences between means were due to chance
nifedipine blocks Ca2+ channels.
explain how blocking calcium channels coudl inhibit insulin secretion
- Ca2+ dont enter cells
- no exocytosis
name the type of differenciated cell that scientist would produce from stem cells in order to treat daibetes mellitus
beta cells
which type of diabetets mellitus is most likely to be improved by stem cell therapy?
-type 1 results from a storgae fo beta cells in the pancreas
- stem cell therapy might increase insulin production
- type 2 dibetetes usually results from insulin resistance (rather than lack of insulin)
- age of patients
- gender of patients
- type of diabetes
- how the improvement was measured
- when the improvement was measured
explain why standard deviation is better than range for meaurng the dispersion of these data
-SD is less affected by the anomaly
- takes ino account every value in the data
- blood glucose measured using the same method
- blood glucose measured the same no. of times a day
- taking into account the patients medical history
- correct use of statistical test - unpaired t test
- insulin is still produced
- beta cells still working
- live cells no longer respond to insulin
- fewer insullin receptors
- if it was tpe 2 then the woman wouldnt produce normal levels of insulin
suggest 2 ways a woman w/ gestational diabetes can manage her condition
- low carbohydrate
- exercise
- manage weight gain
- drugs to control glucose levels
evaluate the treatments for type 1 diabettes that have been used in the past as well as current + potential future treatments (main)
past- from animal pancreas (pig)
current- from eg GM / recombiant bacteria/ humulin
potential treatments - transplant of pancreatic stem cells , immunotherapies / gene therapy
evaluate the treatments for type 1 diabettes that have been used in the past as well as current + potential future treatments ( adv of insulin)
Adv of insulin
animal dervived insulin
- tried + tested method
- early treatment kept ppl alive
‘human’ insulin
- high purity
- less risk of allergic reaction
- lower production cost
- over comes religious issue of animal products
-use of smart pens/ pumps
- pumps moitored by apps
evaluate the treatments for type 1 diabettes that have been used in the past as well as current + potential future treatments (dis of insulin)
animal
- needs to be purified
- risk of allergic reaction
- high production cost
- ethical issues of animal products
‘human’ insulin
- ppl persuaded to change from previous insulin regime eg animal insulin
- some may not understand tech of injection routine
- side effects of pumps eg hard lumps forming under skin
evaluate the treatments for type 1 diabettes that have been used in the past as well as current + potential future treatments ( adv of other treatments)
transplants
- no need for insulin injections
- more physiological control of blood glucose compared w/ injection
- reduce risk of ‘hypos’
- improved quality og life
- stem cells turned into functioning beta cells
immunotherapies
- ‘ reprogrammes’ immune systems
- stops damage to beta cells
evaluate the treatments for type 1 diabettes that have been used in the past as well as current + potential future treatments ( dis of other treatments)
transplants
- requirement of immunosuppression
- availability of donor tissue
- ethical issue associated w/ stem cells
- risk of cancer w/ stem cells (hard to control differenciation)
- not suitable for certain ppl eg those w/ poor kidney function
- may still need low does of insulin
- initial high costs
immunotherapies
- still in early stages
- need clinical trials
