Cells

Question 1

Components of plasma membrane

Answer 1

membrane lipids, membrane proteins, membrane carbohydrates

Question 2

Types of lipids in the plasma membrane

Answer 2

phospholipids, cholesterol, glycolipids

Question 3

functions of the plasma membrane

Answer 3

physical barrier, selective permiability, electrochemical gradients, communication

Question 4

true or false: half of the weight of the plasma membrane is proteins

Answer 4

true

Question 5

true or false: an enzyme is a membrane protein

Answer 5

true

Question 6

passive membrane transport

Answer 6

no expenditure of energy required. substances move down concentration gradient

Question 7

active membrane transport

Answer 7

requires energy (hydrolysis of ATP) involves movement of a substance up a concentration gradient or the formation or loss of a vesicle

Question 8

substances that participate in simple diffusion

Answer 8

O2 and CO2, some fatty acids, ethanol, urea

Question 9

channel mediated diffusion

Answer 9

movement of small ions through water filled protein channels

Question 10

Carrier mediated diffusion

Answer 10

small polar molecules cross membrane with carrier proteins (down gradient)

Question 11

Primary ion responsible for establishing resting membrane potential

Answer 11

Potassium

Question 12

primary active transport

Answer 12

uses energy directly from the breakdown of ATP

Question 13

_____ K ions into the cell, while moving ____ Na ions out of the cell in the K/Na pump

Answer 13

2,3

Question 14

secondary active transport

Answer 14

uses energy from movement of the 2nd substance down its gradient.

Question 15

Symport

Answer 15

two substance moved in the same direction

Question 16

antiport

Answer 16

two substance move in opposite directions

Question 17

exocytosis and endocytosis are examples of what kind of transport

Answer 17

Vesicular

Question 18

neurotransmitters releasing from nerve cells is a great example of what?

Answer 18

exocytosis

Question 19

T/F: The cell membrane is equal parts lipid and protein (50/50) by weight.

Answer 19

True

Question 20

What 2 types of substances are able to penetrate the plasma membrane without assistance?

Answer 20

Small (O2, CO2) and non polar (H20)

Question 21

Name the 3 types of lipids found in a plasma membrane.

Answer 21

Phospholipids, Glycolipids, and cholesterol

Question 22

What are the 2 roles of cholesterol in the lipid bilayer?

Answer 22

Strengthen the membrane

Stabilize the membrane against temperature extremes

Question 23

Glycolipids are found on the inside/outside of the membrane?

Answer 23

Outside

Question 24

Glycolipids help form the sugar coating on the outside of the membrane, known as the __________.

Answer 24

Glycocalyx

Question 25

Name the 4 functions/characteristics of the plasma membrane.

Answer 25

Physical barrier
Selective permeability (regulates entry and exit of ions/nutrients, waste molecules)
Electrochemical gradient
Communication (through receptors)

Question 26

Name the type of membrane protein that is embedded within and extends across the bilateral

Answer 26

Integral protein

Question 27

Name the membrane protein that is not embedded in the bilayer and is loosely attached to the external or interior surfaces of the membrane.

Answer 27

Peripheral proteins

Question 28

Name the 6 different types of membrane proteins.

Answer 28

Transport
Receptor (for ligands)
Identity marker (communicate health and “self”)
Enzymes
Anchoring site for cytoskeleton
Cell adhesion molecule

Question 29

T/F: a transport protein is necessary for passive simple diffusion.

Answer 29

False (they go right through the membrane for simple diffusion)

Question 30

Facilitated diffusion is a passive process and can be either _______ mediated or _______ mediated.

Answer 30

Channel, Carrier

Question 31

Secondary active transport uses energy from the movement of another substance. Two examples are ________, which moves substances in the same direction, and _________, which moves two substances in opposite directions.

Answer 31

Symport and antiport

Question 32

The rate of passive diffusion of a substance down its concentration gradient is determined by what 3 things?

Answer 32

“Steepness” of concentration gradient
Temperature (Fever)
Molecular size (bigger moves slower)

Question 33

Facilitated diffusion through channels or carriers is for_______ or __________ solutes.

Answer 33

Charged, polar

Question 34

Channels are for movement of what?

Answer 34

Small ions, K+, Na+

Question 35

Channels can be leak or gated. Leak are always open. Name the two things that stimulate gated channels to open.

Answer 35

Voltage, Hormones (ligands)

Question 36

__________ mediated diffusion occurs when a substance binds and changes the protein shape, releasing substances on the other side of the membrane.

Answer 36

Carrier

Question 37

Primary active transport uses ATP. What pump have we talked about that is primary active transport?

Answer 37

Na+K+ ATPase pump

Question 38

How many of each ion, Na+ and K+ does ATPase move in/out?

Answer 38

3Na+ out, 2 K+ in

Question 39

Describe the 4 steps of the Na+/K+ pump.

Answer 39

1. Na+ and ATP bind to pump
2. ATP splits into ADP and Pi, protein changes conformation, moves 3 Na+ out
3. Pi released, 2 K+ bind
4. Pump changes conformation, 2 K+ released inside cell

Question 40

___________ involves invagination of the plasma membrane and is an active process.

Answer 40

Endocytosis/pinocytosis

Question 41

_______ uses pseudopodia to engulf and eat and is an active process.

Answer 41

Phagocytosis

Question 42

Receptor-mediated endocytosis uses a ________ coated pit.

Answer 42

Clathrin