AH 1.4 - Communication and Signalling

State the term that describes a wave of electrical excitation along a neuron's plasma membrane.

• Depolarisation

• Hyperpolarisation

• Resting membrane potential

• Action Potential

State the term that describes the change in the membrane potential to a less negative value inside.

• Depolarisation

• Hyperpolarisation

• Resting membrane potential

• Action Potential

State the term that describes the state where there is no net flow of ions across the membrane.

• Depolarisation

• Hyperpolarisation

• Resting membrane potential

• Action Potential

State the term that describes the photoreceptor cells responsible for colour vision.

• Cones

• Rods

• Opsin

• Retinal

State the term that describes the photoreceptor cells in the retina that function in dim light and respond to low light intensities.

• Cones

• Rods

• Opsin

• Retinal

State the term that describes the light sensitive molecules that combines with a membrane protein.

• Cones

• Rods

• Opsin

• Retinal

State the term that describes the type of signalling molecules that can diffuse directly through the phospholipid bilayer.

• Hydrophobic signalling molecule

• Hydrophilic signalling molecule

Which group of signalling molecules do steroid hormones belong to?

• peptide hormones

• neurotransmitter

• extracellular hydrophobic

• extracellular hydrophilic

Only target cells respond to a specific signal because

• receptor molecules in non target cells do not change conformation when the signalling molecule binds

• non target cells do not respond when the signalling molecule binds to its receptor

• only target cells have receptor molecules for the signalling molecule

• signalling molecules only come into contact with target cells

Which letter in the diagram represents the first stage in cell signalling for a peptide hormone molecule?

• A

• B

• C

• D