Cellular energy and respiration

Question 1

Purpose of having fluid in the body

Answer 1

• Medium for metabolic reactions within cell
• Transport of nutrients + waste products
• Lubricant + insulator + shock absorber
• Regulates body temperature

Question 2

Exocytosis (definition)

Answer 2

Transport of substances out of a cell (requires ATP)

Question 3

Exocytosis (process)

Answer 3

• Vesicle containing waste moves towards cell membrane
• Membrane surrounds vesicle and fuses with it
• Contents of vesicle are secreted/released from cell

Question 4

Endocytosis (definition)

Answer 4

Transport of substances inside cell (requires ATP)

Question 5

Endocytocis (process)

Answer 5

• Portion of cell membrane folds around particles outside cell forming vesicle
• Vesicle can take particles inside cell and release them inside cytoplasm

Question 6

diffusion

Answer 6

The net movement of particles from a high concentration, to a low concentration, down a concentration gradient

Question 7

Simple diffusion

Answer 7

non-polar or lipid soluble substances diffuse directly through the plasma membrane

Question 8

Channel-mediated facilitated diffusion

Answer 8

Occurs when channels (transmembrane proteins) transport substances through water filled channels from one side of the membrane to the other.

Question 9

Carrier-mediated facilitated diffusion

Answer 9

Occurs when carriers (transmembrane proteins) transport certain polar molecule that are too large to pass through the membrane channels.

Alterations in the shape of the carrier allow it to first envelope and then release the transported substances.

Question 10

Leak channels

Answer 10

channels, are always open, and simply allow ions or water to move according to concentration gradients.

Question 11

chemically gated channels

Answer 11

channels that open when the appropriate chemical binds.

Question 12

voltage-gated channels

Answer 12

channels that open and close in response to changes in membrane potential.

Question 13

mechanically-gated channels

Answer 13

channels that open in response to physical deformation in the membrane, especially in nerve receptors, as in sensory receptors for touch and pressure.

Question 14

osmosis

Answer 14

movement of water through the selectively permeable membrane from an area of more fluid to less fluid.

Question 15

osmolarity

Answer 15

the total number of solute particles present in one litre of solution.

Question 16

Tonicity

Answer 16

the ability of a solution to change the shape or tone of cells by altering the cell’s internal water volume.