7 Cell Membrane Transport - Part 2 Flashcards
1
Q
Terms
A
Definition
2
Q
Cell membrane
A
It mark cell boundaries and allow for the maintenance of an intracellular composition that differs from the extracellular composition
3
Q
K+
A
What is the main ion of the ICF?
4
Q
Na+
A
What is the main ion in the ECF?
5
Q
Intracellular membranes
A
It allows for the compartmentalization of cell components and maintenance of the concentration gradients required for cell metabolism
6
Q
Intracellular Fluid
A
The fluid within cells that contains high concentrations of potassium (K+), magnesium, and phosphate ions.
7
Q
Extracellular Fluid
A
The fluid within cells that contains large amounts of sodium (Na+), chloride (Cl-), and bicarbonate ions (HCO3-) and nutrients for the cell such as oxygen, glucose, fatty acids, and amino acids
8
Q
False. ECF has a higher concentration of ionized calcium and has higher pH
A
True or False: ECF lowers the concentration of ionized calcium and has a lower pH
9
Q
chloride and bicarbonate
A
What is the balancing anions of ECF?
10
Q
proteins and organic phosphates
A
What is the balancing anions of the ICF?
11
Q
ICF: 14 mEq/L
ECF: 142 mEq/L
A
What is the approximate compositions of Na+ in ICF and ECF?
12
Q
ICF: 120 mEq/L
ECF: 4 mEq/L
A
What is the approximate compositions of K+ in ICF and ECF?
13
Q
ICF: 10 mEq/L
ECF: 105 mEq/L
A
What is the approximate compositions of Cl- in ICF and ECF?
14
Q
ICF: 10 mEq/L
ECF: 24 mEq/L
A
What is the approximate compositions of HCO3 in ICF and ECF?
15
Q
ICF: 1 x 10-4
ECF: 2.5 mEq/L
A
What is the approximate compositions of Ca2+ in ICF and ECF?
16
Q
ICF: 7.1
ECF: 2.5 mEq/L
A
What is the approximate pH of ICF and ECF?
17
Q
ICF and ECF: 290 mOsm/L
A
What is the approximate osmolarity of ICF and ECF?
18
Q
interstitial fluid and plasma
A
ECF is made up of two liquid _____ and ______
19
Q
Integral Proteins
A
These are the proteins that penetrate the lipid bilayer and are involved in transport or signaling processes
20
Q
Peripheral Proteins
A
A type of proteins that are attached only to one surface of the membrane and do not penetrate all the way through
21
Q
Glycocalyx
A
The carbohydrate-rich coating on the external surface of the cell membrane.
22
Q
Lipid bilayer
A
A structure of the cell membrane composed of hydrophobic and hydrophilic regions, acting as a barrier.
23
Q
False. Lipid bilayer is not miscible with either extracellular fluid and intracellular fluid
A
True or false: lipid bilayer is miscible with either extracellular fluid and intracellular fluid
24
Q
True.
A
True or false: lipid-soluble substances can penetrate lipid bilayer and diffuse directly through the lipid substance
25
Transporter, Ion carriers, enzyme and receptor
What are the functions of of membrane proteins?
26
Selective permiability
The ability of the cell membrane to allow some substances to pass through while preventing others, primarily based on their solubility in lipids.
27
Polar and hydrophilic
The head-end of the phospholipid molecule contains the phosphate portion and is soluble in water, making it __________.
28
Non-polar and hydrophobic
The tail-end of the phospholipid molecule is relatively insoluble, making it __________ in water.
29
Fluid Mosaic Model
The model that describes the structure of the plasma membrane as a mosaic of components including phospholipids, cholesterol, proteins, and carbohydrates that provides the membrane with a fluid character.
30
Passive and Active Transport
What are the two types of basic mechanisms of Cell Membrane Transport
31
Facilitated Diffusion
A type of Passive transport that requires a carrier protein with a binding site
32
Simple Diffusion
A type of Passive transport that involves an open pore (a carrier protein without a binding site)
33
Passive Transport
Transport of substances along the concentration gradient or electrical gradient or both
34
Brownian Motion
The random thermal motion of molecules
35
From the region with the higher concentration toward the region with the lower concentration
If a concentration gradient exists, in what direction will the molecules move (if no energy is used).
36
(1) Permeability of the barrier to the molecules, (2) Surface area available, (3) Size of the concentration gradient
What factors affect the rate of diffusion?
37
NO NET MOVEMENT of molecules (equilibrium)
What is Dynamic Equilibrium?
38
Passive Transport
Type of Membrane Transport which does not require the expedition of energy.
39
Oxygen, carbon dioxide, Nitrogen, and alcohol
Give examples of molecules easily permeable to the cell membrane
40
Simple Diffusion
Kinetic movement of molecules or ions occurs through a membrane opening or through intermolecular spaces without any interactions with carrier proteins in the membrane.
41
(1) Amount of substance available
(2) Velocity of kinetic motion
(3) Number and sizes of openings in the membrane through which molecules and ions can move
In simple diffusion, the rate of diffusion is affected by:
42
(1) Through the interstices of the lipid bilayer (if diffusion substance is lipid soluble)
(2) Through protein pores or watery channels that penetrate all the way through some of the large transport proteins
In which parts of the cell membrane does simple diffusion occur?
43
Two types of diffusion
Simple diffusion and Facilitated Diffusion
44
Simple diffusion
Kinetic movement of molecules or ions that occurs through a membrane opening or through intermolecular spaces without any interactions with carrier proteins
45
Carrier proteins are needed in simple diffusion
False; carrier proteins are NOT needed in simple diffusion as the particle/substance here is essentially moving from greater conc. to a lower conc.
46
Rate of diffusion is determined by:
Amount of substance available
47
Simple diffusion can occur through the cell membrane through ________ & ___________.
interstices of the lipid bilayer & protein pores or watery channels
48
Protein pores are not water soluble
False; it is water soluble (e.g. watery channels)
49
Lipid layer of a cell membrane is only permeable to the ff except: O2, CO2, N2, Alcohol, Hydrogen
Hydrogen
50
Rate of diffusion and lipid solubility is directly proportional
TRUE
51
The protein layer of the cell membrane is permeable to water soluble substances like:
Water and Electrolytes or ions
52
In Simple Diffusion through protein layer, there is NO binding site
True, it can be an open conduit or gates channels OR no need for a carrier protein
53
The pores in protein channels are entirely lined up by ________.
integral protein molecules - as they form the channels for the diffusion of water, electrolytes and other substances that CANNOT pass through the lipid layer
54
Protein channels are distinguished by two important characteristics:
Selectively permerable AND Can be opened by gates that are regulated by electrical signals (voltage-gated channels) or chemicals (ligand-gated channels)
55
Nongated Channels
Continuously opened channels
56
Aquaporins, perforins, and nuclear pore complex
Examples of non gated channels
57
Non-gated channels
Aquaporins, perforins, and nuclear pore complex are examples of ____
58
Aquaporin
Also known as water channels
59
Aquaporin
Channels that permit rapid passage of water through cell membranes but exclude other molecules.
60
Aquaporin
They have a narrow pore that permits water molecules to diffuse through the membrane in single files.
61
Aquaporin
Pore is too narrow to permit the passage of any hydrate ions, and is also commonly found in the renal tubules and the erythrocytes.
62
Gated Channels
Closed channels and is opened only when required
63
Gated Channels
Divided into three categories: Voltage-gated Channels, Ligand-gated Channels, and Mechanically-gated Channels
64
Voltage-gated Channels
Channel that the molecular conformation of the gate or of its chemical bonds responds to the electrical potential across the cell membrane.
65
Na+ channel
A strong negative charge on the inside of the cell membrane could presumably cause the outside gates to remain tightly closed, not allowing sodium to enter. What kind of voltage-gated channel is being talked about?
66
Sodium Gates, Open, Allowing
In Na+ Channel under voltage-gated channels, when the inside of the membrane becomes positively-charged, the _____ would _____ suddenly, ______ sodium ions to pass inward through the sodium pores.
67
Na+ Channel
The application being basic mechanism for eliciting action potentials in the nerves responsible for nerve signal. What Voltage-gated channel is being talked about?
68
K+ channel
Potassium gates are on the intracellular ends of the potassium channels and open when the inside of the cell membrane becomes positively-charged. In this process, What Voltage-Gated channel is being talked about?
69
Potassium gates, potassium channels
In K+ channels under voltage-gated channels, _____ are on the intracellular ends of the ______ and open when the inside of the cell membrane becomes positively-charged.
70
Application of K+ Channel
Opening of gates is partly responsible for terminating the action potential. What voltage-gated channel is being talked about?
71
outside
In Na+ channel under voltage-gated channels, the gate is ____
72
inside
In K+ channel under voltage-gated channels, the gate is ____
73
Ligand Gated Channel
Protein channel gate that opens when a chemical substance or a ligand to bind to the protein substance
74
Ligand
A hormone or neurotransmitter that can bind to a receptor and trigger a cellular response.
75
Acetylcholine
Opens the gate after binding and provides a negatively charged pore
76
Application of Ligand Gated Channels
Important for the transmission of nerve signals from one nerve cell to another and from nerve cells to muscle cells, resulting in muscle contraction.
77
Mechanically Gated Channels
Channels opened by mechanical factors and transmits a mechanical signal to an electrical signal
78
Examples of Mechanically Gated Channels
Pressure receptors of Pacinian Corpuscles and deflection of stereocilia
79
Mechanism of the pressure receptors of Pacinian Corpuscles
Pressure → Pacinian corpuscles are compressed → core fibre is deformed → sodium channel opens → receptor potential is developed.
80
Mechanism of the Deflection of Stereocilia
sound → bending of hair cells → K+ enters → depolarization or change in electrical potential → Ca+ enters → transmission of signals that we can interpret
81
K+
voltage-gated channel
82
Ca+
mechanically sesitive channel
83
Facilitated diffusion
A type of diffusion wherein water soluble substances having larger molecules are transported through the cell membrane with the help of a carrier protein
84
Faster
In facilitated diffusion, the substances are transported in and out of the cell membrane at a _____ rate than simple diffusion.
85
False, carrier proteins have a binding site
True or False
Carrier proteins aid in facilitated diffusion by binding a particular substance, then altering their shape to bring that substance into or out of the cell. However, they do not have a binding site.
86
Specificity, saturation, and competition
What are the 3 characteristics of carrier protein?
87
Transport Maximum or TM
A limited number of carrier binding sites are available within the particular plasma membrane for a specific substance, Thus, there is a limit to the amount of substance a carrier can transport across the membrane in a given time.
88
Simple diffusion: As the concentration of the diffusion substance increases, the diffusion rate (through an open channel) also increases
Facilitated diffusion: As the concentration of the diffusion substance increases, the diffusion rate approaches a maximum (Vmax/transport maximum)
What is the main difference between simple diffusion and facilitated diffusion in terms of the diffusion rate as the concentration of the substance increases?
89
The diffusion rate approaches a maximum (Vmax/transport maximum) due to the saturation of the carrier proteins.
In facilitated diffusion, what limits the diffusion rate even if the concentration of the substance continues to increase?
90
GLUT4 is indeed a glucose transporter that is activated by insulin and increases the rate of facilitated diffusion of glucose by 10-20 fold in insulin-sensitive tissues, such as adipose tissue and striated muscles.
What role does GLUT4 play in insulin-dependent glucose transport?
91
Glucose co-transport is an active transport mechanism, while the mechanism involving GLUT4 is an example of facilitated diffusion, where glucose moves from an area of higher concentration to an area of lower concentration without requiring energy.
What distinguishes glucose co-transport from the mechanism involving GLUT4?
92
fick's first law of diffusion
Mathematical statements that describe how particles under random thermal motion tend to spread from a region of higher concentration to a region of lower concentration to equalize concentration in both regions
93
surface area and concentration gradient/difference
Rate of diffusion based on fick's first law of diffusion is directly proportional to both
94
thickness of the membrane
Rate of diffusion based on fick's first law of diffusion is inversely proportional to the
95
negative
For Fick's First law of diffusion, the change of concentration difference over the membrane thickness is _____, so multiplying it by a negative diffusion coefficient will result in a positive value
96
fick's first law of diffusion
What law is the foundation of a lot of concepts regarding respiratory therapy and medicine
97
increase
Increase or Decerease: Conditions/diseases such as pneumonia, TB, pulmonary fibrosis, or emphysema _______the thickness of the alveolar membrane, causing impaired diffusion manifested by symptoms such as hypoxemia and hypoxia
98
1. Membrane Permeability of Solutes 2. Molecular Weight 3. Concentration Gradient 4. Surface Area 5. Membrane Thickness
Five factors that affect Difussion
99
1. Solute is permeable and small 2.High concentration difference 3. High surface area 4. Thin membrane thickness
What is an ideal Scenario for dissuion
100
Membrane Permeability
The cell membranes of lung cells are highly permeable to oxygen. When you breathe in, oxygen diffuses quickly from the air in your lungs into your blood because the membrane allows oxygen to pass through easily. What kind of factor of diffusion is this example?
101
increases
the time required for diffusion ____ with the square of the distance
102
range of diffusion / diffusion distance
dictates rate of delivery of nutrients to the cell and tissue vascularization
103
in vivo
study on actual life
104
in vitro
study through the tube
105
lipid solubility
factor that determines how rapidly a substance diffuses through the lipid bilayer
106
oxygen, nitrogen, carbon dioxide, alcohols
substances with high lipid solubility that can dissolve directly in the lipid bilayer
107
lipid
the cell membrane is permeable to ___-soluble molecules
108
water
the cell membrane is impermeable to ___-soluble molecules
109
ion channels, protein channels, carrier proteins
facilitate the diffusion of water soluble molecule to be able to pass through the membrane
110
permeability
the ease with which molecules cross biological membranes
111
hydrophobic core
only lipid-soluble molecules and some small molecules are able to freely pass through the lipid bilayer because of its ___
112
FALSE
True or false: ions and large polar molecules can pass through the lipid bilayer
113
size, electrical nature
The permeability of a molecule through the membrane depends on its ___ and ____.
114
high
membrane permeability of hydrophobic, nonpolar, or fat-soluble molecules
115
high
membrane permeability of small, uncharged polar or water-soluble molecules
116
low
membrane permeability of large, uncharged polar molecules
117
low
membrane permeability of charged, molecular species (e.g. ions)
118
membrane transport protein
Membrane-impermeant molecules and ions cross the membrane with the aid of a specific ___.
119
Oxygen (O2)
The most permeable substance across the cell membrane
120
Sodium Ions
The least permeable substance across the cell membrane
121
Oxygen > Water > Glucose > Sodium Ions
What is the gradient of permiability of substances across the cell membrane
122
Aquaporins
Transmembrane proteins that easily allows the rapid passage of water
123
Protein channels and carrier-mediated/facilitated diffusion
Impermeable water-soluble substances diffuses through the cell membrane using?
124
Selectively permeability and gated-pores
Two important characteristics of protein channels
125
Selective permeability / specificicty
Characteristics such as the shape, diameter, electrical charges and chemical bonds contribute to the _______ of the protein channel
126
Gated-pores
Means of controlling permeability of protein channels
127
Voltage-gated
A type of gated protein channels that are regulated by electrical signals / charges
128
Chemical/Ligand-gated
A type of gated protein channels that are regulated by the presence of a certain substance resulting in a confomational change
129
Sodium Channels
An example of voltage-gated protein channel
130
Acetylcholine (ACH)
An example of a ligand-gated protein channel
131
Non-gated channels
Aqueous pores, aquaporins, perforins, and nuclear pores are examples of ______ which are always open
132
Diameter of pore (Size) and electrical charges
Provides the selectivity and specificity of pores
133
Carrier proteins
Type of proteins that are used in both facilitated diffusion and active transport
134
Vmax
The maximum rate of diffusion where the rate of diffusion cannon be higher than this value
135
Specificity, saturation, competitive inhibition
Carrier proteins have the following characteristics
136
Glucose Transporter 4 (GLUT 4)
An example of a carrier protein
137
Both are passive processes requiring no usage of energy (ATP)
Simple and facilitated diffusion are similar because _____
138
Concentration gradiet, electrical potential difference, and pressure differences
Driving force of both facilitated and simple diffusion
139
high to low
Simple and facilitated diffusion always occur in a ____ direction
