Ch 4 & 5

Question 1

Protocell

Answer 1

1st cell membrane on earth, made from ring of lipids (liposomes) allowing materials to diffuse

Question 2

Endosymbiosis

Answer 2

organism within another, ancestor of eu cells engulfed pro cell forming endosymbiotic relationship with host, merge to eu cell with mitochondria

Question 3

Andreas Schimper Theory

Answer 3

Plastids in plants make & store food, chloroplast is example, in 1967 proposed mitochondria & flagella are endosymbiotic bodies

Question 4

Limits of cell size

Answer 4

small SA:V- rate decreases and cell dies
larger SA:V- rate increases & efficient

Question 5

Prokaryotic cells

Answer 5

Bacteria, archaea
No nucleus (DNA unbound in nucleoid/prim & plasmid/seco)
No membrane bound organelles
Cytoplasm in plasma membrane

Question 6

Eukaryotic cells

Answer 6

DNA in nucleus with envelope
Membrane bound organelles
Cytoplasm b/w plasma membrane & nucleus

Question 7

Membranes

Answer 7

Made of amphipathic lipids & proteins held by phobic interactions

Question 8

Fluidity in membranes

Answer 8

Lipids shift fast proteins shift slow
cholesterol anchors membranes
reduces fluidity at moderate temps & resists solidification at low temps

Question 9

Temp on fluidity

Answer 9

Membrane remains fluid with lower temp with unsaturated hydrocarbon tails (double bond with bend)

Question 10

Proteins in cell membrane

Answer 10

Integral/intrinsic- all the way through
Peripheral/extrinsic- one side

Question 11

Protein in membranes function

Answer 11

Transport (int), enzyme activity, cell recognition, intercellular joining, signal transduction (ext)

Question 12

Cell-cell recognition

Answer 12

ability to distinguish cell from another binding to molecules
glycoproteins are flags/id’s for proteins to recognize
cells high five each other (mainly peripheral)

Question 13

Diffusion

Answer 13

Movement of particles from high to low concentration
If no energy- passive

Question 14

Osmosis

Answer 14

Diffusion of water across membrane from high to low water concentration until equal

Question 15

Isotonic

Answer 15

Water diffuses at same rate, no net movement

Question 16

Hypertonic

Answer 16

More solute than water, water leaves faster than enters, salt water

Question 17

Hypotonic

Answer 17

Less solute than water, water enters faster than leaves, burst

Question 18

Facilitated diffusion

Answer 18

Help transport polar molecules with transport proteins

Question 19

Plasmolysis

Answer 19

Cytoplasm shrinks & membrane pulls away from cell wall when cell loses water in hypertonic

Question 20

Deplasmolysis

Answer 20

Cytoplasm & membrane have normal turgor pressure by taking water from hypotonic

Question 21

Water potential

Answer 21

=pressure+solute potential
moves from higher to lower water potential

Question 22

Increasing solute

Answer 22

Decreases solute & water potential
Water will attract to solute and less likely to move away

Question 23

Increasing pressure

Answer 23

Increases pressure & water potential because more energy for water to move

Question 24

Passive Transport

Answer 24

Diffusion & facilitated diffusion
No ATP, driven by conc gradient (high-low conc)

Question 25

Active transport

Answer 25

Needs ATP Against gradient (low-high conc)

Question 26

Exocytosis

Answer 26

Active transport getting things out of cell

Question 27

Endocytosis

Answer 27

Active transport getting things into cell

Question 28

Primary active transport

Answer 28

Directly uses ATP, sodium potassium pump exchanges sodium for potassium ions

Question 29

Intercellular joining proteins

Answer 29

Membrane proteins hook at gap/tight junctions Direct cell communication

Question 30

Plasmodesmata & desmosomes

Answer 30

Plasmo- fluid bond in plants Desmo- deeper connection than TJ in animals

Question 31

Tight & gap junctions

Answer 31

Gap- ion exchange in animals Tight- H20 tight seals in animals