Chapter 5 Review on Matter, Membranes, and Signaling

These flashcards cover key concepts related to potential energy, membrane structure, transport processes, signal transduction, and the behavior of water in solutions.

What is potential energy in the context of matter?

Potential energy is the energy possessed by matter due to its location or structure.

Which property is necessary for protein A to bind to protein B?

Protein A must have regions of shape and charge that are complementary to those on Protein B.

What describes the structure of a biological membrane?

Two layers of phospholipids with proteins either crossing the layers or on the surface of the layers.

How do the membranes of eukaryotic cells vary?

Certain proteins are unique to each kind of membrane.

What can lead to rapid passage through the phospholipids of the plasma membrane?

Small nonpolar molecules can pass directly through.

What is the function of Structure E in a cell?

Detection of environmental change.

What role do transport proteins have in facilitated diffusion?

Transport proteins allow solutes to move passively down their concentration gradient across the membrane.

What is true regarding osmosis?

The presence of aquaporins speeds up the process of osmosis.

How should a cell increase phosphate concentration in the cytosol if it's lower outside?

By using active transport.

What characterizes active transport?

It involves the expenditure of ATP and moves ions against their concentration gradient.

What happens if sugar is added to one side of a U-shaped tube?

The water level on the opposite side will rise.

What occurs if the selectively permeable membrane's pores become larger?

More water could pass to the right side, causing the water level to rise higher.

How is glucose typically transported into a cell against its concentration gradient?

By cotransport with a proton or sodium ion using ATP energy.

What describes exocytosis and endocytosis?

Both involve active transport and change the surface area of the plasma membrane.

What does the term 'ligand' refer to in cell biology?

A molecule that can bind specifically to a receptor site.

Why are signal transduction pathways often lengthy?

Each step amplifies the signal, producing greater numbers of activated products.

What are among the most common second messengers?

Calcium ions and cAMP.

What is the significance of phosphorylation cascades in signal transduction?

They amplify the original signal manyfold.

What characterizes lipid-soluble signaling molecules like aldosterone?

They can cross membranes of all cells but affect only target cells with intracellular receptors.

What initiates a signal transduction pathway?

A signal molecule binding to a receptor.

What is the second of the three stages of cell signaling?

Transduction.

How does water move in a solution of differing solute concentrations?

Water moves from an area of higher free water concentration to lower free water concentration.