Cell Structure Flashcards

Question

Examples of membranes

Answer 1

-Cristae in mitochondria -Thylakoids in chloroplasts -Membrane in lysosome

Answer 2

-Polar, hydrophilic phosphate head -Two non-polar, hydrophobic fatty acid tails

Answer 3

-When exposed to water -Two parallel rows of phospholipids, with heads facing out and tail facing in

Answer 4

-Span the whole length of the membrane

Answer 5

-Outer surface of the membrane

Answer 6

-Intrinsic -Provide a hydrophilic channel through the membrane -Polar molecules move along a conc gradient -Passive

Answer 7

-Intrinsic -Change shape to transport molecules -Can be active or passive

Answer 8

-Attached to carbohydrate chains -Involved in cell adhesion and signalling -Binds with chemical signals -Can also act as enzymes

Answer 9

-Attached to carbohydrate chains -Allow the immune system to recognise the cell as self -Also known as antigens

Answer 10

-Also has a hydrophilic head and hydrophobic tail -Positioned between phospholipids -Adds stability -Regulates membrane fluidity (more cholesterol means less permeable membranes)

Answer 11

-Passive process -Between two areas -During equilibrium movement is equal in both directions

Answer 12

-Small molecules (CO2, O2) can pass right through -Larger fat soluble molecules (hormones) can diffuse as they dissolve in the bilayer

Answer 13

-Higher temperature gives particles more kinetic energy, increasing diffusion. -Steeper concentration gradient increases overall movement. -Greater diffusion distance leads to slower diffusion. -Smaller molecules diffuse more rapidly -A large surface area leads to more diffusion

Answer 14

-Through channel or carrier proteins. -Takes place with polar (lipid insoluble) molecules such as glucose.

Answer 15

-The movement of water molecules down a water potential gradient. -Through a partially permeable membrane. -Passive process.

Answer 16

-Molecules are small enough to pass directly through. -Aquaporins (protein channels) allow them to pass through more rapidly.

Answer 17

-Conc of solutes is greater outside than inside the cell. -Higher water potential in cell, water moves out. -Leads to cell crenation (cell shrivelling)

Answer 18

-Conc of solutes greater inside the cell that outside. -Lower water potential inside cell, water moves in. -Leads to cytolysis (cells swelling)

Answer 19

-Tendency of water molecules to diffuse from one region to another. -Measured in kilopascals (kpa) -Pure water has a ᴪ of 0, the highest possible value. -Concentrated solutions have a lower ᴪ

Answer 20

-Movement of substances against the concentration gradient. -Active process, requires energy from ATP. -Involves carrier proteins through the membrane.

Answer 21

-Moves Na ions outside cell and K ions inside. -Uses carrier proteins with a complementary shape to the molecule. -Allows hydrolysis of ATP to ADP and phosphate, releasing energy. -Binding of the phosphate molecule to the protein causes the carrier to change shape. -Therefore the molecule can pass through.

Answer 22

-Movement of substances out of a cell. -Substances contained in a vesicle and carried towards the membrane. -Vesicle fuses with membrane and empties contents outside.

Answer 23

-Movement of substances into a cell. -Cell membrane bulges inwards and forms a vesicle. -An example of this is phagocytosis.

Answer 24

-Cis end faces nucleus, trans end faces cell wall -Receives proteins from ER and modifies them by adding sugars. -Secretes vesicles that fuse to cell membrane.

Cell Structure Flashcards

(49 cards)