B2.1 Membranes and Transport Flashcard

Front

What is exocytosis?

Back

Exocytosis is the process by which cells expel materials in vesicles that fuse with the plasma membrane, releasing their contents outside the cell.

Front

What does 'hydrophilic' mean?

Back

Hydrophilic literally means 'water loving', referring to substances that are attracted to water.

Front

What does 'semi-permeable' mean in relation to lipid bilayers?

Back

Semi-permeable means that the lipid bilayer allows some substances to pass through while blocking others.

Front

What is the difference between saturated and unsaturated fatty acids?

Back

Saturated fatty acids have no double bonds between carbon atoms and contain the maximum number of hydrogen atoms, while unsaturated fatty acids have one or more double bonds.

Front

What occurs when a neuron reaches threshold potential?

Back

When a neuron reaches threshold potential, voltage-gated sodium channels open, allowing sodium ions to flow into the neuron.

Front

Define active transport.

Back

Active transport is the movement of substances across a cell membrane against their concentration gradient, requiring energy (ATP).

Front

What is pinocytosis?

Back

Pinocytosis is a form of endocytosis where the cell engulfs liquid from the surrounding environment.

Front

What is carrier-facilitated diffusion?

Back

Carrier-facilitated diffusion is a passive transport process where specific molecules are transported across the cell membrane via protein carriers.

Front

Explain the role of phospholipids in cell membranes.

Back

Phospholipids form the basic structure of cell membranes, creating a bilayer that is hydrophobic on the inside and hydrophilic on the outside.

Front

What is the significance of the fluid mosaic model?

Back

The fluid mosaic model describes the structure of cell membranes as a mosaic of various proteins that float in or on the fluid lipid bilayer, allowing for flexibility and movement.