Science -- Cell Transport -- 6th grade Simcoe

Active Transport

It uses energy, transports from lower concentration to higher concentration

Does Passive transport require energy

no

Passive Transport examples

1. diffusion 2. osmosis

If the substance entering the cell was in higher concentration inside the cell than outside the cell, what type of transport would be required? Explain your answer.

Active Transport because it is moving from a lower concentration to a higher concentration.

How is active transport different than simple diffusion and facilitated diffusion?

Active transport uses energy Simple diffusion and facilitated diffusion does not use energy.

How does facilitated diffusion differ from simple diffusion?

Both simple and facilitated diffusion move molecules from high to low but facilitated diffusion needs transport proteins to carry substances.

Why isn't cellular energy required for the passenger molecule to be carried across the cell membrane by the carrier molecule?

Cellular energy isn't required because it is moving from a higher concentration to a lower concentration.

Diffusion

Does not use energy, transports from higher concentration to lower concentration.

The prefix exo- means "out of" and the prefix endo- means "taking in". How do these meanings relate to the meaning of exocytosis and endocytosis?

Exocytosis is moving particles out of the cell. Endocytosis is taking particles into the cell.

What is the difference between facilitated diffusion with the help of a carrier molecule and active transport with the help of a transporter protein?

Facilitated diffusion with the help of a carrier molecule does not require energy, it is going from higher concentration to lower concentration. Active Transport with the help of a transporter protein requires energy, it is going from a lower concentration to a higher concentration.

What is a concentration gradient?

How the particles are moving.

Facilitated Diffusion is the diffusion of what?

Molecules from a higher concentration to a lower concentration

What does it mean for a molecule to diffuse down a concentration gradient?

Molecules moving down a concentration gradient, the molecules go from a higher concentration to a lower concentration.

Osmosis

Movement of water from higher concentration to lower concentration, does not use energy

Passive Transport

Needs a carrier molecule, or a transporter protein; goes from higher concentration to lower concentration, does not use energy

Predict: If the transport proteins that carry amino acids into a cell stopped working, how might the process affect the cell?

The cell might die because it wouldn't get enough amino acids. Amino acids are used by the ribosomes to make proteins.

Infer: What might you conclude about the membrane structure of the final vesicle formed during exocytosis and the cell membrane?

The final vesicle becomes the cell membrane.

Why do the passenger molecules need to be helped by the carrier molecule?

The passenger molecules need help because they can't fit through the cell membrane.

Assume a person has defective carrier molecules for a given substance. Explain what effect this would have on the person's cell.

Whatever substance that cannot be carried will not be able to enter the cell.

Do you think that endocytosis and exocytosis can occur within the same cell? Explain your reasoning.

Yes -- because cells need to be able to balance substances inside and outside the cell. (homeostasis)

Osmosis is what?

diffusion of water