OCR A-Level Biology Module 5 Communication, homeostasis and energy overview quiz quiz

High hydrostatic pressure created by a wider afferent than efferent arteriole

Active transport of water molecules across the basement membrane into the capsule

Osmosis of water from the collecting duct back into the surrounding capillaries

The action of ADH increasing the permeability of the glomerular capillary wall

Less ADH is released, so the collecting duct becomes less permeable and dilute urine is produced

More ADH is released, making the collecting duct more permeable so more water is reabsorbed

The kidneys stop filtering the blood until the water potential returns to its normal level

Glucagon is released to trigger the reabsorption of water from the loop of Henle

Voltage-gated sodium channels opening to let sodium ions flood into the axon at rest

Calcium ions entering the axon and binding to troponin within the cell membrane

The sodium-potassium pump moving 3 sodium ions out for every 2 potassium ions in

Acetylcholine binding to receptors and keeping the sodium channels permanently open

Potassium ions diffuse out of the axon through voltage-gated potassium channels

The sodium-potassium pump stops, allowing the membrane potential to drift positive

Calcium ions leave the axon, raising the potential to its peak of plus 40 millivolts

Sodium ions diffuse into the axon through voltage-gated channels

Myelin insulates the axon so the impulse jumps between nodes of Ranvier (saltatory conduction)

Myelin generates extra action potentials continuously along the whole length of the axon between the nodes

Myelin actively pumps more sodium ions across the membrane to speed up depolarisation

Myelin removes the refractory period so action potentials can fire one after another

Potassium ions leaving the presynaptic neurone, which triggers the vesicles to fuse and release their contents

Calcium ions entering through voltage-gated channels, causing vesicles to fuse with the membrane

Acetylcholinesterase diffusing across the synaptic cleft to break the vesicles open

Sodium ions leaving the postsynaptic neurone and travelling back across the cleft

Alpha cells; they raise blood glucose by promoting the breakdown of stored glycogen

Beta cells; they raise blood glucose by stimulating glycogenolysis and gluconeogenesis

Beta cells; they lower blood glucose by increasing uptake and glycogenesis

Alpha cells; they lower blood glucose by increasing glucose uptake into liver cells

It is the hormone that binds the surface receptor and activates adenylyl cyclase

It breaks down glycogen directly into glucose without activating any enzyme cascade

It enters the cell from the blood and binds to an intracellular receptor in the nucleus

It is the second messenger that activates protein kinase inside the cell

Accumulates on the shaded side and promotes cell elongation there

Accumulates on the lit side, where it inhibits the elongation of the growing cells

Is destroyed by light equally on both sides, so neither side of the shoot elongates

Causes the lit side to elongate faster than the shaded side of the bending shoot

Provides the energy for the power stroke by being hydrolysed at the myosin head

Binds troponin, moving tropomyosin to expose the myosin-binding sites on actin

Detaches the myosin heads from the actin filament so the sarcomere can lengthen

Breaks down acetylcholine at the neuromuscular junction to end the stimulation

The carbon dioxide that is fixed by rubisco during the light-independent reactions

The Calvin cycle, where it is released as RuBP is regenerated from triose phosphate

The photolysis of water in the light-dependent stage

The glucose produced at the end of the light-independent reactions of photosynthesis

TP (triose phosphate) directly

Glucose and oxygen gas

Reduced NADP and ATP

GP (glycerate 3-phosphate)

Oxidative phosphorylation

Glycolysis in the cytoplasm

The link reaction in the matrix

The Krebs cycle in the matrix

It is the first electron donor, passing electrons into the chain at the start of the process

It is the final electron acceptor, combining with electrons and protons to form water

It is split during photolysis to release the energy that drives the synthesis of ATP

It is converted directly into carbon dioxide as the electron transport chain operates