Plasma Membrane

Question 1

8 Functions of the Plasma Membrane

Answer 1

2.) Cell compartmentalization
3.) Decides which cells can pass through and not pass through, which can attach and which can’t attach
4.)Anchour
5.)Produces energy such as ATP
6.)Attacking an organ after a transplant because it can tell it’s not yours
7.)Cell division
8.) Cells stick together

Question 2

2 types of metabolic pathways

Answer 2

Anabolic (form small to big)
Catabolic (from big to small)

Question 3

Parts of a membrane

Answer 3

lipid bilayer
proteins
cholesterol
glycolipids

Question 4

Amphipathic

Answer 4

A molecule has both hydrophobic and hydrophilic parts

Question 5

What types of groups are always hydrophilic

Answer 5

Hydroxyl

Question 6

What do unsaturated fatty acids look like and example

Answer 6

chains that are double-bonded together and kinked

Ex: canola oil that always stays liquid

Question 7

What is the fluidity of the lipid bilayer influenced by

Answer 7

temperature and composition of lipid molecules

Question 8

What happens when temp drops in a molecule

Answer 8

molecules pack tightly together and from a thick membrane gel

Question 9

Functions of a membrane protein

Answer 9

transport things in and out of the cell

send a message to other cells warn them of an attack

Question 10

Types of membrane proteins

Answer 10

integral and peripheral

Question 11

Integral proteins

Answer 11

inside the membrane

Question 12

Peripheral membrane

Answer 12

on the surface
held together with non-covalent bonds
made of polar and non-polar amino acids
mostly in the cytoplasmic side of the membrane

Question 13

Passive transport

Answer 13

no energy
against the concentration gradient
low -> high concentration

Question 14

Active transport

Answer 14

energy required
against concentration gradient
low -> high concentration

Question 15

4 types of passive transport

Answer 15

-simple diffusion
-facilitated diffusion
-osmosis
-turgor pressure

Question 16

simple diffusion

Answer 16

-few things go through the membrane
-aquaporin helps water get across
-wants to be at equilibrium

Question 17

osmosis

Answer 17

-movement across a selectively permeable membrane
-only with water
-water flows to higher concentration on balance out

Question 18

facilitated diffusion

Answer 18

-channel (open on both sides)
-Gate (open one end at a time)
-Follows the concentration gradient
-uses proteins

Question 19

Turgor pressure and types

Answer 19

-in plant cells
Hypertonic (shrinks, water goes out)
Isotonic (equal, water goes in and out at an equal rate)
Hypotonic (fat, water goes in)

Question 20

5 Types of active transport

Answer 20

uniport
symport
antiport
exocytosis
endocytosis

Question 21

uniport

Answer 21

1 molecule goes across a membrane

Question 22

symport

Answer 22

2 different kinds of molecules go across a membrane in the same direction and time

Question 23

antiport

Answer 23

one type of molecule coming out while another type of molecule comes in

Question 24

How many kinds of junction are there for animal and plant cells

Answer 24

4 animal
2 plant

Question 25

2 Basic techniques of breaking open a cell and example

Answer 25

mechanical/physical (liquid nitrogen, blender) chemical (osmosis)

Question 26

What is centrifugation

Answer 26

spinning a sample so fast that the molecules separate into layers

Question 27

4 Animal cell junctions

Answer 27

desmosomes adherens gap tight

Question 28

adherens junctions (3)

Answer 28

-made of actin and cadherin -hold cell membranes together but not close enough that they fuse together -like paces when tiling a floor

Question 29

desmosomes (5)

Answer 29

-like buttons on a sofa -connections that hold cells together and attach inside the cell -placed randomly -space big enough between that water and ions can flow -Found in skin and intestines

Question 30

Tight junctions (4)

Answer 30

-found in trachea -seal adjacent cells together tightly -creates a waterproof seal -like quilting stiches

Question 31

Gap junctions (4)

Answer 31

-open and close like an iris diaphragm -how cells communicate -connect cells with a protein channel that allows them to communicate and transfer small molecules and ions -2-4nm space between membranes

Question 32

2 types of plant cell junctions

Answer 32

middle lamella plasmodesmata

Question 33

middle lamella

Answer 33

a glue made of a polysaccharide called pectin that glues two cells together

Question 34

plasmodesmata

Answer 34

cytoplasm that runs between to plant cells though a hole in the cell wall

Question 35

the fluid mosaic model of membrane shows that

Answer 35

membrane components can move within the lipid bilayer

Question 36

passive transport of molecules across a membrane is

Answer 36

an energy independent process

Question 37

What can't pass through the membrane by diffusion

Answer 37

ions

Question 37

transmembrane proteins may be single peptides or complexes

Answer 37

true

Question 37

chromosomes are composed of

Answer 37

chromatin

Question 38

In prophase, chromosomes condense. How many total chromatids are there in humans at this point

Answer 38

92