Lab 4: Cell Structure And Exhange With Environment

Question 1

Diffusion

Answer 1

tendency of small molecules to flow from an area of high solute concentration to an area of low solute concentration, eventually reaching an equilibrium where there is no net change in concentration on either side (when there’s no barrier).

Question 2

Osmosis

Answer 2

Movement (diffusion) of water across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration.

Question 3

If you had a glass tube which was about 2 meters long, would the osmometer attain concentration equilibrium and stop rising?

Answer 3

No, because sucrose and water will never mix.

Question 4

When would the column in the osmometer stop rising?

Answer 4

When gravity counteracts osmotic pressure.

Question 5

Cell membrane

Answer 5

Selectively permeable; maintains intracellular environment.

Question 6

Nucleus

Answer 6

Contains DNA.

Question 7

Nuclear membrane

Answer 7

Has nuclear pores that permit certain molecules to pass through.

Question 8

Nucleolus

Answer 8

Body within nucleus involved in synthesis of rRNA and ribosomes.

Question 9

Mitochondria

Answer 9

Site of ATP production.

Question 10

Rough endoplasmic reticulum

Answer 10

Site of protein synthesis and processing.

Question 11

Smooth endoplasmic reticulum

Answer 11

Lipid synthesis and processing.

Question 12

Ribosomes

Answer 12

Complexes of rRNA and proteins that translate mRNA into proteins.

Question 13

Golgi apparatus

Answer 13

Proteins, lipids, and carbs syntehsized by rER and ER passes thru * to be processed and packaged.

Question 14

Lysosomes

Answer 14

Contains enzymes that break down products of digestion and damaged cell parts.

Question 15

Centrioles

Animal cells

Answer 15

Made of a group of microtubules. A pair are found within centrosome.

Question 16

Chloroplast

Plant cells

Answer 16

Production of sugars via photosynthesis.

Question 17

Cell wall

Plant cells

Answer 17

• Protects cell.
• Gives it it’s shape and rigidity.

Question 18

Central vacuole

Plant cell

Answer 18

• Storage for water.
• Provides tugor pressure on cell wall.

Question 19

Hypertonic solution

Answer 19

Solution that has greater solute concentration than solution on other side of a membrane.

Question 20

Isotonic

Answer 20

Solution that has same solute concentration as solution on other side of a membrane.

Question 21

Hypotonic solution

Answer 21

Solution that has less solute concentration than solution on other side of a membrane.

Question 22

What is plasmolysis? When does it happen?

Answer 22

• Wherein plant cell loses water and the plasma membrane shrinks away from the cell wall.
• Occurs when solution is hypertonic to the inside of cell.

Question 23

Osmotic pressure

Answer 23

Amount of force applied to a solution to prevent solute from moving across a semipermeable membrane.

Question 24

Turgor pressure

Answer 24

• Water pressure within the cell that pushes plasma membrane against the cell wall, providing rigitdity.
• Happens when cell is placed in a hypotonic solution.

Question 25

Amyloplast

Answer 25

Organelle in plant cells that store starch.

Question 26

Compound microscopes are used to view. . .

Answer 26

• Most eukaryotic cells.
• Some bigger organelles (e.g. mitochondria).

Question 27

Electron microscopes are used to view. . .

Answer 27

• Most organelles.
• Viruses.