Cell Membrane, Passive Transports, and Water Systems (copy)

What is dehydration synthesis?

Making something bigger, like a molecule.

What is hydrolysis?

The process of adding water back to break down molecules.

What does electronegativity measure?

The affinity of an atom to gain electrons.

What is the relationship between solid water and liquid water?

Solid water (ice) is less dense than liquid water.

Why does ice float?

Because it expands and is less dense than liquid water.

What is osmosis?

Concentration of water moving from high to low concentration.

What is diffusion?

Concentration of gases moving from high to low concentration.

What is passive transport?

Movement of substances from high to low concentration without energy.

What does ATP stand for?

Adenosine Triphosphate.

What is the role of the cell membrane?

Controls what enters and exits the cell to maintain homeostasis.

What is a phospholipid bilayer?

Two layers of phospholipids that make up the cell membrane.

What are the polar components of phospholipids?

The phosphate head is polar (hydrophilic) and the fatty acid tails are non-polar (hydrophobic).

What is the fluid mosaic model?

Model describing the cell membrane as flexible and composed of various components.

What are integral proteins?

Proteins that span the entire membrane, functioning as channels or carriers.

What are peripheral proteins?

Proteins that attach to the membrane but do not span it completely.

What does selectively permeable mean?

The cell membrane only allows certain substances to pass through.

What is the intercellular space?

The space between the fatty acid tails in the phospholipid bilayer.

What are amphipathic molecules?

Molecules that have both hydrophilic and hydrophobic parts.

What is the function of cholesterol in the membrane?

Connects phospholipids together and maintains membrane stability.

What is a glycoprotein?

A molecule made up of a protein and a sugar chain.

What is a glycolipid?

A molecule consisting of a fat and a sugar chain.

What happens when you use energy from ATP?

ATP converts to ADP, losing one phosphate group.

What do channel proteins do?

They create tunnels for specific molecules to pass through the membrane.

What do carrier proteins do?

They transport molecules across the membrane by changing shape.

What is aquaporin?

A protein that selectively allows the passage of water through the cell membrane.

What is the function of a cell wall?

Provides structural integrity and helps retain water in cells.

What occurs during lysis?

A cell bursts open.

What happens to a cell in a hypertonic solution?

It shrinks as water leaves the cell.

What does isotonic mean?

A state where there is no net movement of water; perfect balance.

What happens to a cell in a hypotonic solution?

It expands and can potentially burst as water enters the cell.

What is turgor pressure in plant cells?

Pressure that keeps plant cells from bursting in hypotonic solutions.

How do saltwater fish prevent dehydration?

They pump salt out of their gills to maintain osmotic balance.

What is facilitated diffusion?

Movement of molecules across the membrane through proteins without energy.

What is the main driving force of diffusion?

The concentration gradient.

What are the components of a phospholipid?

A polar head and two non-polar fatty acid tails.

What type of molecules can easily move through the phospholipid bilayer?

Non-polar and small molecules.

What is the primary function of membranes?

To regulate the movement of substances in and out of the cell.

What is meant by the term 'osmotic pressure'?

The pressure exerted by water movement across a selectively permeable membrane.

What happens to plant cells in a hypertonic solution?

The cell membrane pulls away from the cell wall.

What is a contractile vacuole?

A vacuole in protists that helps regulate water levels.

How do molecules with no charge behave in the phospholipid bilayer?

They can easily move through the bilayer.

What is the effect of cold temperatures on hydrogen bonds in water?

They form a stable hexagonal structure in ice.

What qualities define proteins embedded in the cell membrane?

They serve as channels or carriers for substance transport.

What does the term 'concentration gradient' refer to?

The difference in concentration of a substance across a space.