Week 5 session 3

Substance X is moving into a cell from an area of low concentration. Which of the following is responsible for transporting substance X into the cell?

• Proteins through the process of active transport
• Phospholipids through the process of active transport
• Proteins through the process of passive transport
• Phospholipids through the process of passive transport

In the picture to the right, which area(s) represent(s) the hydrophobic part of the phospholipid membrane?

• Structure A
• Structure B
• Structures A & B
• Neither structure A or B

Describe the movement of "Molecule D" in the apparatus shown to the right over time.

• They will stay in the same place
• They will move across the they are membrane until they are all on side B
• They will move across the membrane until they reach an equilibrium.
• "Molecule D" will move to side A, but "Molecule C" will stay in the same place.

On the diagram below, indicating the direction of osmosis (water)

• Into the cell
• Outside the cell
• Remain the same inside and outside the cell
• Remain the same outside, but not inside

Molecule X moves across a cell membrane by active transport.  Which statement best indicates the relationship that represents diffusion?

• HIgh conc >low
   Uses ATP
• High Conc > Low
  Does not use ATP
• Low Conc > High
  Uses ATP
• Low Conc > High
  Does not use ATP

Low density lipoproteins (LDL’s or bad cholesterol) are taken up “in-bulk” into the cytoplasm of a cell. This process is an example of 

• endocytosis

• exocytosis
• micrfilaments

• osmosis

Which protein is a major component of microtubules in the cytoskeleton?

• a) Actin

• b) Myosin

• c) Tubulin

• d) Keratin

Actin filaments are strong, rigid structures

• True

• False

What cell structure is involved in protein synthesis?

• mitochondria

• nucleus

• cell membrane

• ribosomes

Which of the following statements is NOT true regarding prokaryotic cells?

• Bacteria are prokaryotes.

• All prokaryotes are unicellular.

• Prokaryotes have structures within the cell to protect the DNA.

• Prokaryotes are very simple cells.