Lecture7

Question 1

What does mitochondria do?

Answer 1

Change energy from one form to another, the sites of cellular respiration and generates ATP

Question 2

What is cellular respiration?

Answer 2

a metabolic process that uses oxygen to generate ATP

Question 3

Where are chloroplasts found?

Answer 3

in plants and algae

Question 4

Where is the site of photosynthesis?

Answer 4

chloroplasts

Question 5

What is the structure of mitochondria and chloroplasts like?

Answer 5

enveloped by a double membrane
contain free ribosomes and circular DNA molecules

Question 6

How do mitochondria and chloroplasts grow and develop?

Answer 6

somewhat independently in cells

Question 7

What organisms do chloroplasts and mitochondria share similarities with?

Answer 7

bacteria

Question 8

The similarities between bacteria and chloroplast and mitochondria led to what theory?

Answer 8

endosymbiont theory

Question 9

What is endosymbiont theory?

Answer 9

Mitochondria and chloroplasts were once free living prokaryotes that were engulfed by an early eukaryotic ancestor ~1.5 billion years ago

Question 10

Who was behind the endosymbiont theory?

Answer 10

Lynn Margulis

Question 11

How are phospholipids form?

Answer 11

They are self-assembled due to the hydrophobic effect

Question 12

What does amphipathic mean?

Answer 12

A molecule that has both hydrophilic and hydrophobic parts

Question 13

What affects membrane fluidity?

Answer 13

molecule properties

Question 14

What are the adaptations that allow the cell to maintain fluidity?

Answer 14

habitat (temperature)
nature of lipids
unsaturated vs saturated fatty acids
cholesterol

Question 15

How should the fluidity of a membrane behave?

Answer 15

not too rigid and not too fluid

Question 16

What is the essential molecule that maintains membrane integrity?

Answer 16

Cholesterol

Question 17

What is the function of cholesterol?

Answer 17

maintain membrane integrity (fluidity buffer)

Question 18

Who developed the fluid mosaic model?

Answer 18

SInger and Nicholson

Question 19

What does the fluid mosaic model state?

Answer 19

that a membrane is a fluid structure (phospholipids) with a “mosaic” of various proteins embedded in it
Plasma membrane, nuclear membrane, membrane of organelles (ER, mitochondria), vesicles

Question 20

How do phospholipids move?

Answer 20

in the plasma membrane freely within the bilayer

Question 21

How do phospholipids drift?

Answer 21

laterally

Question 22

True/False: Rarely, a lipid may flip-flop transversely across the membrane bilayer (usually enzyme mediated)

Answer 22

true

Question 23

What are lipid rafts?

Answer 23

saturated phospholipids, cholesterol, and protein

Question 24

what are non-rafts?

Answer 24

unsaturated phospholipids and proteins

Question 25

Where are integral (transmembrane) proteins located?

Answer 25

They span the membrane

Question 26

What substances cross the semipermeable membrane easily?

Answer 26

small hydrophobic molecules

Question 27

What substances have a hard time crossing the semipermeable membrane?

Answer 27

charged molecules without a transport protein

Question 28

What are transport proteins?

Answer 28

proteins that allow substances to cross the barrier

Question 29

What are the two kinds of membrane transport?

Answer 29

passive and active

Question 30

What is passive transport?

Answer 30

requires a protein but not energy. uses channels and carriers

Question 31

What is another name for passive transport?

Answer 31

facilitated diffusion

Question 32

What is active transport?

Answer 32

requires protein and energy e.g. ATP. uses pumps

Question 33

What is osmosis?

Answer 33

The movement of water from an area of high concentration to an area of low concentration