Active Transport and Vesicular Transport

Flashcards covering vesicular transport (endocytosis, exocytosis, pinocytosis, phagocytosis), primary active transport via the sodium-potassium pump, and secondary active transport via the sodium-glucose symporter.

What cellular process is referred to as 'self eating' in the lecture?

Phagocytosis.

What cellular process releases unneeded vesicle contents outside of the cell?

Exocytosis.

What happens to the plasma membrane during endocytosis?

The plasma membrane pinches in, forming a vesicle that contains material from outside the cell.

From which organelle do the vesicles involved in exocytosis originate?

The Golgi body (or Golgi apparatus).

What does the Golgi apparatus add to proteins to turn them into ligands (chemical messengers)?

Special chemicals.

How is pinocytosis described in terms of fluid intake?

Taking in little samples of the extracellular fluid (ECF).

What source of energy is used in primary active transport to phosphorylate a pump?

ATP (or a little piece of it).

What type of energy generated by primary active transport drives secondary active transport?

Potential energy.

Where is sodium ($\text{Na}^+$) naturally found in higher concentration?

In the extracellular fluid (ECF).

What is the primary goal of primary active transport regarding sodium balance?

To reestablish homeostasis or balance.

How many sodium ions bind to the carrier protein in the sodium-potassium pump?

Three ($3$) sodium ions.

What activates the carrier protein so that bound sodium ions can move?

Phosphorylation of the carrier (dephosphorylating ATP and adding a phosphate group to the ATP binding site).

Along what gradient direction does potassium move when entering the cell via the sodium-potassium pump?

Against its concentration gradient, moving from low concentration in the ECF to high concentration inside the cell.

How many potassium ions bind to the carrier protein to be transported into the cell?

Two ($2$) potassium ions.

What causes the dephosphorylation and relaxation of the sodium-potassium pump carrier protein?

The binding of potassium to the carrier.

What is the net movement and ratio of ions in the sodium-potassium pump?

Three ($3$) sodium ions go out, and two ($2$) potassium ions come in.

Why does active transport require energy from the cell?

Because it moves ions against their concentration gradient, from where they are less concentrated to where they are more concentrated.

In the secondary active transport cotransport example, which two substances move into the cell together?

Sodium ions and glucose.

Does sodium move down or against its concentration gradient in the sodium-glucose cotransporter protein?

Sodium ions move down their concentration gradient.

Does glucose move down or against its concentration gradient in the sodium-glucose cotransporter protein?

Glucose moves against its concentration gradient.

What allows the carrier protein to stay open to receive potassium after sodium is released?

The phosphate group that remains attached to the carrier.

How is potential energy defined in the lecture?

Stored or picked up energy.

What form of energy is created when sodium ions begin moving down their concentration gradient?

Kinetic energy (energy of motion or movement).

What serves as the driving force for secondary active transport?

Kinetic energy from the movement of sodium ions down their gradient.

What specific type of transporter protein brings glucose along with sodium into the cell?

A sodium-glucose symporter.

Why does secondary active transport not involve transferring a phosphate group directly to the carrier?

Because it does not use ATP directly and lacks an ATP binding site.

Why is the movement of sodium and glucose classified as a symporter example rather than an antiporter?

Because both sodium and glucose are moving in the same direction.

Do pinocytosis and phagocytosis show receptor specificity according to the lecture?

No, they do not show any of those receptors, so no specificity is shown.

What happens to the membrane of a vesicle during exocytosis?

The membrane of the vesicle fuses with the plasma membrane (cell membrane).

How long was the break scheduled at the conclusion of chapter three before transitioning to chapter 17?

A five-minute ($5\text{ minute}$) break.