Quizlet BIOL 5

What are the main components of cell membranes?

Phospholipids.

What characteristic makes phospholipids unique?

They are amphipathic molecules.

What part of the phospholipid attracts water?

The hydrophilic head.

What do the hydrophobic tails of phospholipids do?

Repel water.

What defines saturated fatty acids?

They contain only single C-C bonds.

What distinguishes unsaturated fatty acids?

They contain at least one double C=C bond.

What is a phospholipid bilayer?

Two layers of phospholipids with tails oriented inward.

What model describes the membrane structure with diverse components?

Fluid Mosaic Model.

What are integral proteins?

Proteins fully embedded in the phospholipid bilayer.

What are transmembrane proteins?

Integral proteins that span the entire membrane.

Where are peripheral proteins located?

On the membrane's surface.

What role do carbohydrates play in the cell membrane?

They are involved in cell recognition.

What are glycoproteins?

Carbohydrates bonded to proteins in the membrane.

What are glycolipids?

Carbohydrates bonded to lipids in the membrane.

What is membrane fluidity?

Flexibility of the membrane, influenced by various factors.

What role does cholesterol play in membranes?

Regulates membrane fluidity across temperature changes.

How does low temperature affect membranes?

It makes them rigid.

What is the effect of high temperature on membranes?

It increases fluidity.

What does asymmetry of the membrane refer to?

The inner and outer surfaces of membranes differ.

What is the function of cell signaling in membranes?

Membranes receive signals and initiate cellular responses.

What is cell adhesion?

The ability of membranes to help cells stick to each other.

What are transporters in membranes?

Proteins that facilitate movement of substances across membranes.

What do receptors do in membranes?

They bind to external signals.

What is the function of enzymes in membranes?

They catalyze biochemical reactions.

What is the role of phosphate groups in phospholipids?

They are the polar component of phospholipids.

What are fatty acid chains in phospholipids?

Hydrophobic tails that can be saturated or unsaturated.

What functions do membranes serve?

Define cell borders, manage transport, and signal reception.

How does passive transport work?

It allows movement across the membrane without energy input.

What is osmosis?

The diffusion of water across a semipermeable membrane.

What is diffusion?

The movement of molecules from high to low concentration.

What does tonicity refer to?

The relative concentration of solutes in solutions.

What is a selectively permeable membrane?

A membrane that allows specific molecules to pass through.

What are permeant molecules?

Molecules that can cross the phospholipid bilayer.

What is a concentration gradient?

The difference in concentration across a space.

What state is reached at equilibrium?

The concentrations are equal on both sides.

What is facilitated diffusion?

Transport of substances via membrane proteins.

What do channel proteins do?

Allow specific ions to pass through the membrane.

What are carrier proteins?

Proteins that bind and transport specific substances across membranes.

What are hydrophobic molecules?

Nonpolar molecules that easily pass through membranes.

What happens to large polar molecules in membranes?

They cannot pass through membranes.

What are ions in terms of membrane permeability?

Charged molecules that cannot cross membranes freely.

What factors affect diffusion?

Concentration, mass, temperature, surface area, and pressure.

What are gated channel proteins?

Proteins that open in response to specific signals.

What happens to molecular movement at high temperatures?

It increases, enhancing diffusion rates.

What is the effect of large surface area on diffusion?

It increases diffusion speed.

What is the role of blood pressure in diffusion?

It forces solutions through membranes, enhancing diffusion.