The correct answers are: The lipid bilayer and proteins exist side by side without covalent bonds between them and Some proteins and lipids undergo lateral diffusion along the inner or outer surface of the membrane
According to fluid mosaic model, there is a lipid bilayer that gives fluidity and in which the protein molecules are embedded.
The membrane is mosaic because there is a pattern of different types of molecules that are put together. Molecules are constantly moving in two dimensions.
Components of the cell membrane include:
• Phospholipids – Form a bilayer
• Cholesterol –improves stability and reduce fluidity
• Proteins –integral (transmembrane) or peripheral
• Sugars-usually attached to proteins.
Answer:
The correct answer is c) action potential
Explanation:
Action potential starts with the opening of the sodium channel in response to the stimulus given to the neuron by neurotransmitter. This opening of sodium ion channel results in the influx of sodium ions in the receptive region of neurons from outside. This is the depolarization step of action potential.
Before this step, the neurons are negatively charged from inside and positively charge outside and this stage it is considered to be resting stage.
As the amount of Na⁺ reaches the threshold value the action potential fires and send the electric signals down to axons.
Therefore action potential occurs because of the influx of Na⁺ ions through chemically gated channels in the receptive region of a neuron.