unit 2 test review

Question 1

why must cells remain small

Answer 1

to maintain a large surface area to volume ratio

Question 2

Surface area must be large enough to all the cell to:

Answer 2

obtain resources
eliminate waste
acquire/dissipate thermal energy
exchange chemicals/energy with environment

Question 2

why should cells have a large SA:V ratio

Answer 2

allows increased rates of chemical exchange between cell and environment

Question 3

light microscope characteristics

Answer 3

Visible light passes through specimen
Refracts light so specimen is magnified
Magnify up to 1000X
Specimen can be alive/moving
Color
Can’t see organelles other than nucleus

Question 4

electron microscope charactersitics

Answer 4

Focuses a beam of electrons through/onto specimen
Magnify up to 1,000,000 times
Specimen non-living and in vacuum
Can see organelles

Question 5

Track the journey of a protein/polypeptide from the endoplasmic reticulum to how it would exit a cell.

Answer 5

DNA is in chromatin in nucleus
Then go to rough ER
Translate message into amino acid sequence
Then to golgi with transport proteins by vesicles
Goes thru cis face side of golgi
Then leaves through the trans face
Leaves on a transport vesicle to then go to membrane
Then exocytosis out of the cell

Question 6

animal cells

Answer 6

Only membrane
Lysosomes
Microvilli

Question 7

Plant cells:

Answer 7

Central vacuole
Chloroplasts
Cell wall+membrane

Question 8

Prokaryote

Answer 8

No nucleus (Nucleoid-DNA concentration)
DNA in a nucleoid
Cytoplasm/Cytosol
No organelles other than ribosomes
Small size
Primitive
i.e. bacteria

Question 9

eukaryote

Answer 9

Has nucleus and nuclear envelope
Cytoplasm/Cytosol
Membrane-bound organelles with specialized structure/function
Much larger in size
More complex
i.e. plant/animal cell

Question 10

where are chloroplasts found? function? what do they do? what does it contain and what is its purpose?

Answer 10

Only in plants
Function: site of photosynthesis
converts light energy into chemical energy ie. carbohydrates
Contains chlorophyll (green pigment) for capturing sunlight energy

Question 11

compartmentalization

Answer 11

the way organelles present in the eukaryotic cells live and work in separate areas within the cell in order to perform their specific functions more efficiently

Question 12

how do membranes achieve compartmentalization

Answer 12

Internal membranes create a greater SA:V ratio
Nucleus, mitochondria, ER, golgi, chloroplasts all have internal membrane folds that help compartmetalize

Question 13

why is compartmentalization important

Answer 13

More efficiency in cell’s functions

Question 14

components of membrane

Answer 14

phospholipids bilayer
proteins
cholesterol

Question 15

phospholipid bilayer properties

Answer 15

cellular barrier/border (selectively permeable)
Impermeable to polar molecules
Amphipathic

Question 16

proteins determine

Answer 16

membrane’s specific function

Question 17

proteins 7 functions

Answer 17

Transport
Enzymatic activity
Signal transduction
Cell-cell recognition
Intercellular joining
Attachment to the cytoskeleton and extracellular matrix
Peripheral proteins and integral proteins

Question 18

cholesterol purpose in membrane

Answer 18

acts as a fluidity buffer - resisting changes in fluidity as temperature changes

Question 19

fluid mosaic model shows

Answer 19

Membrane fluidity
Cholesterol in animal cell membrane
Movement of phospholipids
Proteins floating throughout phospholipid bilayer

Question 20

what membrane has no kinks

Answer 20

saturated fatty acid tails - viscious

Question 21

what membrane has kinks

Answer 21

unsaturated fatty acid tails - fluid

Question 22

6 functions of membrane

Answer 22

Transport
Enzymatic activity
Signal transduction
Cell-cell recognition
Intercelluar joining
Attachment to cytoskeleton + extracellular matrix

Question 23

channel proteins

Answer 23

embedded in the cell membrane & have a pore for materials to cross

Question 24

carrier proteins

Answer 24

can change shape to move material from one side of the membrane to the other

Question 25

amphipathic meaning

Answer 25

a molecule that has a hydrophilic and a hydrophobic region

Question 26

how does the amphipathic features of the phospholipid bilayer affect its function

Answer 26

Only some molecules are able to go through the membrane because it is nonpolar or polar

Question 27

CAN pass through lipid bilayer

Answer 27

fats & other lipids, hydrocarbons, CO2, Oxygen, hydrophobic molecules

Question 28

CANNOT pass through lipid bilayer

Answer 28

polar molecules (H2O), ions (charged)-salts, ammonia, large molecules (starches, proteins)

Question 29

diffusion

Answer 29

High to low concentration Passive transport No energy is needed Solute moves DOWN concentration gradient until reached equilibrium (then no net movement)

Question 30

Facilitated diffusion

Answer 30

High to low concentration Passive transport No energy needed Needs proteins to move Channel proteins: embedded in cell membrane and have pore fro materials to cross (like water slide) Carrier proteins: can change shape to move material from one side of membrane to other

Question 31

Hypertonic

Answer 31

more solute, less water (when comparing the solution to the cell) If the solution is hypertonic Solute will move inside of cell Water will move out of cell

Question 32

hypotonic

Answer 32

less solute, more water (when comparing the solution to the cell) If the solution is hypotonic Solute will move out of cell Water will move inside of cell

Question 33

isotonic

Answer 33

equal solute, equal water (when comparing the solution to the cell) If solution is istonic Solute and water will both move equally until equilibrium (not really because they were already equal so they don’t need to reach equilibrium) NO NET MOVEMENT

Question 34

hypertonic plant and animal cells

Answer 34

Animal cell: shrivels Plant cell: plasmolysis

Question 35

hypotonic plant and animal cells

Answer 35

Animal cell: burst (lysed) Plant cell: turgid (normal)

Question 36

isotonic plant and animal cells

Answer 36

Animal cell: normal Plant cell: flaccid

Question 37

Understand how molecules move via active transport.

Answer 37

(Membrane potential also called voltage) Moves substances AGAINST concentration gradient Needs energy (ATP) Low to high Carrier proteins

Question 38

sodium potassium pump

Answer 38

Na+ ions: high OUT and low IN K+ ions: low OUT and high IN

Question 39

what influences the direction that ions move in the membrane

Answer 39

electrochemical gradient

Question 40

Describe how a membrane potential is created across a membrane. What is this also called?

Answer 40

Created by differences in distribution of positive and negative ions Also called voltage

Question 41

steps of sodium potassium pump

Answer 41

1. cytoplasmic Na binds to sodium-potassium pump 2. Na binding stimulates phosphorylation by ATP 3. phosphorylation causes the protein to change its shape, Na is expelled to the outside 4. Potassium binds on the extracellular side and triggers release of the phosphate group 5. loss of the phosphate restores the protein's original shape 6. potassium is released and the cycle repeats

Question 42

pinocytosis

Answer 42

molecules are taken up when extracellular fluid is “gulped” into tiny vesicles

Question 43

Phagocytosis

Answer 43

cellular digestion, lysosomes fuse with food vacuoles

Question 44

receptor-mediated endocytosis

Answer 44

binding of ligands to receptors triggers vesicle formation

Question 45

Understand how the molarity of the unknown solutions (colored) was determined and what it meant when bags/cells gained or lost mass. Explain how the molarity of the veggie was calculated.

Answer 45

Bags gained mass when they were hypertonic to solution Bags lost mass when they were hypotonic to solution Water potential (and graph) on lab explained: Molarity in reference of concentrations of solute Water potential of carrot equal to water potential of solution That one point tells us the molarity of that solute in that solution

Question 46

water potential calculation

Answer 46

Water potential = Solute potential + Pressure potential

Question 47

Solute potential

Answer 47

-ICPT (cannot be positive because of the negative sign in front of the I) Ionization number Concentration Pressure Temperature