Module 5 - Communication, Homeostasis & Energy Flashcards
Abscisic Acid (ABA)
Plant hormone that stimulates stomatal cloning, maintains seed dormancy & triggers cold protective responses
Abscission
The shedding of leaves in plants
Acetylcholine
Type of neurotransmitter that is used for communication between neurones
Actin
Type of protein filament found in myofibrils, forms thin filaments consisting of 2 long twisted chains
Actin-myosin binding site
A site on actin that is normally blocked by tropomyosin, during it becomes exposed, allowing myosin head to attach
Actin-myosin cross-bridge
Cross-bridge forms when a myosin head attaches to the myosin binding site on an actin filament
Adenylyl cyclase
Enzyme that catalyses the conversion of ATP to cAMP
Adrenal glands
Glands which are located on top of kidneys & produce adrenaline & steroid hormones
Adrenaline
Hormone that is secreted by adrenal glands under stressful conditions, serves as ‘primary messenger’ activating adenylyl cyclase
Afferent arteriole
Larger diameter arteriole which carries blood to glomerulus for ultrafiltration
Alkaloids
Group of nitrogenous compounds found in plants, are bitter-tasting & affect metabolism of animals/insects that take them in
All-or-nothing principle
Any generator potential that reaches/exceeds the threshold potential will produce an action potential of equal magnitude
Alpha cells (α cells)
Cells found in pancreas which secrete glucagon into the blood to raise glucose concentration
Anisotropic (A) bands
Darker bands in myofibril, consist of overlapping actin & myosin filaments
Anabolic steroid
Class of PED that are structurally similar to testosterone & used illegally by athletes to promote muscle growth
Anterior pituitary gland
Region of pituitary gland that produces & secretes hormones
Antidiuretic hormone (ADH)
Hormone released from posterior pituitary gland that increases reabsorption of water in kidney tubules
Aquaporin
Membrane channel used for selective transport of water in & out of the cell
Autonomic nervous system
Branch of nervous system that carries nerve impulses to muscles & glands, controls involuntary activities & have 2 divisions:
sympathetic
parasympathetic
Auxins
Class of plant hormones that control cell elongation, produce tropisms, prevent abscission, maintain apical dominance & stimulate production of ethene
Axon
Extension of nerve cell that carries impulses away from cell body
Beta (β) cells
Cells found in pancreas which secrete insulin into blood to lower glucose concentration
Bile Canaliculi
Vessels which collect the bile produced by hepatocytes
Blinking reflex
Involuntary blinking of eyelid when an object is held close to eye, last reflex to be lost
Cardiac muscle
Myogenic muscle found in walls of the heart
Central Nervous System (CNS)
Brain & spinal cord
Cerebellum
Region of brain that controls muscle coordination & non-voluntary movement e.g. balance & posture
Cerebrum
Largest region of brain, consists of 2 hemispheres, receives sensory information from receptors & sends information via motor neurones to effectors, responsible for all involuntary responses
Cholinergic synapse
Synapse which uses acetylcholine as its neurotransmitter
Creatine phosphate
Compound stored in muscles, serves as phosphate reserve enabling ATP regeneration
Cutting
Small section of the root/stem of an adult plant
Cyclic AMP (cAMP)
‘Secondary messenger’ involved in action of adrenaline that activates protein kinase
Dendron
Extension from nerve cell that carries impulses towards cell body
Depolarisation
Rapid influx of Na+ into cell, causes it to lose its negative charge & membrane potential increases
Ectotherm
Type of organisms which is dependent on its environment to maintain its body temp
Effector
Organ/tissue/cell that produces a response to stimulus
Efferent arteriole
Smaller diameter arteriole which carries blood away from the glomerulus after ultrafiltration
Endocrine signalling
Type of signalling that uses hormones secreted by endocrine cells into blood which produce an effect on receptors
Endotherm
Type of organisms which can regulate its own body temp without relying on external heat sources
Ethene
Plant hormone that stimulates ripening of fruit & promotes abscission in deciduous trees
Excitatory postsynaptic potential (EPSP)
Impulse which stimulates an action potential in postsynaptic neurone
Excretion
Process of removing metabolic waste from an organism
Fight or Flight response
Physiological reaction of body in response to potentially dangerous situation
Geotropism
Plant’s growth response to gravity
Gibberellins
Plant hormone that controls stem elongation, trigger growth of pollen tube during fertilisation & stimulate mobilisation of food storage reserves during seed germination
Glomerular filtrate rate (GFR)
Method of measuring kidney function which assesses the amount of blood plasma filtered per unit of time & produces values which should be above 90mL/min in healthy adults
Glomerulus
Bundle of blood vessels at beginning of kidney nephron where ultrafiltration takes place
Haemodialysis
Type of dialysis used where a patient’s blood is fed into dialysis machine & passed across an artificial membrane to remove waste
Hepatic artery
Main artery which supplies liver tissue with oxygenated blood from heart
Hepatic Vein
Main vein which takes deoxy blood from liver back to heart
Homeostasis
Maintaining a constant internal environment around an optimum despite external change
Hormonal Weed killers
Hormones (synthetic dicot auxin) that alter plant metabolism promoting rapid growth that’s unsustainable
Hormones
Cell signalling molecules produced by endocrine glands & releases into blood. Travel to target cells & bind to specific receptors, initiating response, effects of hormones are usually long-lasting
Hyperpolarisation
Drop in membrane potential below resting potential after repolarisation due to open K+ ion channels
