CHAPTER 5

Question 1

define kinetic energy. give examples.

Answer 1

Kinetic energy → the energy of motion/ of things moving; it could be of objects, of molecules, or of waves(light, sound).

Question 2

define potential energy. give examples.

Answer 2

-Potential energy → stored energy (EX: if you have a spring from a mattress and you push down on it; it now has potential energy) the energy of position above the other (gravitational) (EX: water behind a dam)
-Food? Gasoline? Both contain potential energy

Question 3

define the law of conservation of energy. what does the conversion of energy generate?

Answer 3

-the law of conservation of energy: energy cannot be created or destroyed; in other words kinetic energy and potential energy are converted back and forth
-All energy conversion (potential to kinetic) generate heat

Question 4

what is ATP?

Answer 4

Adenosine triphosphate(ATP) → the main energy source for cellular work (nothing happens in your cells without ATP)

Question 5

describe and diagram how ATP provides energy for cellular work and the ATP cycle.

Answer 5

-“DESCRIBE”: Triphosphate tail is unstable, due to 3 negatively charged phosphate groups; they repel each other; this is potential energy because they are forced to stay together. As a result that last P- charge breaks away: which releases energy to do work →ATP needed for mechanical, transport, and chemical reactions

-“DIAGRAM”: Adenosine triphosphate – releases energy→ which then turns into adenosine diphosphate plus a phosphate –fuel from food is used for cellular respiration (energy is absorbed) → Adenosine triphosphate is made

Question 6

define passive transport. what are the three types of passive transport in a cell?

Answer 6

-passive transport means there is no energy required for this to happen it happens spontaneously and passively; all molecules have random thermal motions which means they vibrate
-diffusion, osmosis, and facilitated diffusion

Question 7

define diffusion. give examples.

Answer 7

-Diffusion is the overall movement of solute molecules going from high concentration to low concentration (they move down the concentration gradient)
-EX:

Question 8

define osmosis. give examples.

Answer 8

Osmosis is movement of water across a semipermeable membrane (like a plasma membrane) also high concentration to lower concentration
-EX: red blood cell in distilled water (hypotonic)

Question 9

what are the the three types of osmosis

Answer 9

hypotonic, isotonic, and hypertonic

Question 10

hypotonic

Answer 10

referring to a solution that has a high concentration of water and a low concentration of solute (ex:distilled water)

Question 11

isotonic

Answer 11

equal amounts of water in or out.

Question 12

hypertonic

Answer 12

referring to a solution that has a low concentration of water and a high concentration of solute

Question 13

define facilitated diffusion. give examples.

Answer 13

-increasing rate of diffusion by using transport proteins; higher concentration to lower concentration
-EX: H+ ions, glucose (OH- groups)

Question 14

describe the behavior of plant cells in hypertonic, isotonic, and hypotonic solutions.

Answer 14

hypertonic solution: plant cell loses so much water that the plasma membrane pulls away from the cell wall
isotonic solution: plant cell is flaccid
hypotonic solution: plant cell is plump and turgid which is a healthy plant cell

Question 15

describe the behavior of animal cells (RBCs) in hypertonic, isotonic, and hypotonic solutions.

Answer 15

Hypertonic solution: RBC shrivels up
Isotonic solution: RBC is normal
Hypotonic solution: RBC takes in too much water and pops

Question 16

define plasmolysis. give examples.

Answer 16

Plant cells in a hypertonic solution
Ex: plant cell loses so much water => plasma membrane pulls away from cell wall => kills the cell

Question 17

define osmoregulation. give examples.

Answer 17

The control of the gain or loss of water and dissolved solutes in an organism
Ex: in a paramecium living in freshwater ponds -> hypotonic environment
H2O inside -> uses contractile vacuoles to squeeze our excess water

Question 18

define active transport.

Answer 18

Uses transport proteins that pump solute against the concentration gradient (lower concentration to higher concentration)
- requires energy = ATP

Question 19

how are large molecules transported?

Answer 19

By using endocytosis and exocytosis

Question 20

define exocytosis.

Answer 20

Move materials out of the cell
Ex: secretory proteins

Question 21

define endocytosis.

Answer 21

Move materials into the cell
Ex: How amoebas feed

Question 22

know all exercises done in the diffusion/osmosis lab.

Answer 22

-brownian motion: mixed water and milk→ put under microscope → we saw random movement of particles; small particles moved faster than bigger

-put 4 potatoes into four different solutions → one in distilled water; one in 0.2 M sucrose; one in 0.4 M sucrose; one in 0.6 M sucrose → we see the potatoes in distilled water and 0.2 M sucrose increases in size (hypotonic) and potatoes in 0.4 M & 0.6M sucrose decrease in size (hypertonic)

-put dialysis tube (semipermeable membrane) that is tied closed at the bottom contains glucose and starch and is placed in a testing tube that is filled with IKI (iodine); inside dialysis tubing it turns dark blue because IKI is going through → then we get three testing tube and fill one with tap water, one with tap water (constant); one with sample from testing tube; one with 30% glucose (comparing) → add Benedict’s reagent to each; then warm all three up and see the color differences → the sample from test tube and the 30% glucose turn red/orange → which means glucose went through the dialysis tubing. the starch cannot go through the tubing and we know this because the IKI on the outside did not turn dark blue.

-put two epidermis in one distilled water; and in 1M NaCl → see the difference; distilled water epidermis is more plump (hypotonic). 1 M NaCl epidermis goes through plasmolysis which means the cell membrane pulls away from the cell wall (hypertonic).

-red blood cells in distilled water , artificial tears, and 1M NaCl → first solution red blood cell bursts (hypotonic); second solution red blood cell is normal (isotonic); third solution red blood cell shrinker (hypertonic)