Lab 4

Question 1

selectively permeable

Answer 1

some substances can pass through while some can’t

Question 2

diffusion

Answer 2

tendency for solute to spread from an area of high solute concentration to an area of low solute concentration as a result of constant random movements

Question 3

is diffusion active or passive?

Answer 3

passive, does not require energy

Question 4

how is equilibrium achieved?

Answer 4

solute evenly distributed across solvent, no net movement

Question 5

solute

Answer 5

substance dissolved in a liquids

Question 6

solvent

Answer 6

liquid the solute is dissolved in

Question 7

what organelle controls diffusion in a cell?

Answer 7

cell’s plasma membrane

Question 8

osmosis

Answer 8

movement of water from an area of high water concentration to an area of low water concentration across a selectively permeable membrane

Question 9

what is the rate of osmosis dependent on?

Answer 9

temperature, solute concentration

Question 10

cell membrane

Answer 10

selectively permeable membrane that separates interior of cell from external environment

Question 11

nucleus

Answer 11

organelle containing DNA, chromosomes, and genetic info

Question 12

Nuclear Envelope/Membrane

Answer 12

semipermeable membrane separating interior of nucleus from the cell’s cytoplasm, has nuclear pores

Question 13

nucleolus

Answer 13

region in nucleus where RNA is manufactured and ribosomal subunits assembled

Question 14

mitochondria

Answer 14

organelle that breaks down carbs to produce energy in the form of ATP via cellular respiration

Question 15

rough endoplasmic reticulum

Answer 15

where proteins are synthesized, folded, packaged, and processed, contains ribosomes

Question 16

smooth endoplasmic reticulum

Answer 16

where lipids such as phospholipids are synthesized and processed

Question 17

ribosomes

Answer 17

macromolecular machines that manufacture proteins by transcription and translation

Question 18

golgi apparatus

Answer 18

shipping centre of cell, packages molecules into vesicles, modifies lipids and proteins

Question 19

lysosomes

Answer 19

recycling center of cell, has digestive enzymes that break down cell parts and substances

Question 20

centrioles

Answer 20

may help organize microtubule assembly, a pair is found within the centrosome in animal cells

Question 21

chloroplast

Answer 21

uses solar energy to synthesize carbs via photosynthesis

Question 22

cell wall

Answer 22

durable outer layer that gives structural support to plant cells

Question 23

central vacuole

Answer 23

storage compartments for water in plant cells

Question 24

how many layers thick is the onion epidermis?

Answer 24

one layer

Question 25

where is the nucleus usually located in plant cells?

Answer 25

between the plasma membrane and vacuole membrane

Question 26

what microscope is necessary to see membranes?

Answer 26

transmission electron microscope

Question 27

how thick are elodea leaf cells?

Answer 27

two cells thick

Question 28

why can you not see vacuole of elodea leaf on compound microscope?

Answer 28

it is enclosed by a membrane as thing as plasma membrane (10nm) and is not pigmented by chlorophyll

Question 29

Magnification formula

Answer 29

M = Si/So

Question 30

What is general shape of chloroplasts?

Answer 30

oblong

Question 31

cytoplasmic streaming/cyclosis

Answer 31

organelles move along cytoskeleton inside cells

Question 32

Why do onion epidermis cells lack chlorophyll?

Answer 32

onion epidermis do not carry out photosynthesis and instead serve as protection

Question 33

Amyloplasts

Answer 33

storage compartments for starch

Question 34

what are three microscopic structural differenves between plant and animal cells?

Answer 34

plant cells are rigid,boxy, have chloroplasts, and a large central vacuole whereas animal cells lack both organelles and lack structure

Question 35

what does it mean when a cell is turgid?

Answer 35

central vacuole is filled, causing pressure within the cell because cell membrane is snug against the cell wall, causing cell rigidity

Question 36

what is plasmolysis?

Answer 36

Contraction of the cell contents
due to the loss of water

the process of water leaving a cell due to the solution outside of the cell being hypertonic compared to inside, leading to the central vacuole collapsing and plasma membrane shrinking away from the cell wall

Question 37

why does cell wall not shrink during plasmolysis?

Answer 37

cell wall is rigid and maintains its structure

Question 38

what can you do to make wilted veggies turgid again?

Answer 38

add lettuce to water, a hypotonic solution relative to the inside of cell, so that water moves across semipermeable plasma membrane of plant cells through osmosis

Question 39

what happens to plant cells in hypotonic solution?

Answer 39

water enters cell which has a lower concentration of water compared to outside, leading to turgor pressure developing

Question 40

what happens to plant cells in hypertonic solution?

Answer 40

water leaves cell which has a higher concentration of water compared to outside, leading to plant cells plasmolyzing and shrinking

Question 41

what happens to plant cells in isotonic solution?

Answer 41

nothing, no net movement, stays the same due to equilibrium already established

Question 42

hypertonic solution

Answer 42

solutions with higher conc. of solute compared to solution inside the cell

Question 43

turgor pressure

Answer 43

outward pressure exerted by fluid contents of a living plant cell

Question 43

isotonic solution

Answer 43

solutions with same conc. of solute compared to solution inside cell

Question 43

hypotonic solution

Answer 43

solutions with lower conc. of solute compared to solution inside cell

Question 44

osmotic pressure

Answer 44

Measure of the
tendency of water to move across a
differentially permeable membrane;
visible as an increase in liquid on the
side of the membrane with higher solute
concentration