Exam 2 Flashcards
Chapters 13 - 15 (no chapters 17-19 (151 cards)
1
Q
Plasma membrane is
A
selectively permeable
2
Q
Proteins in plasma membrane:
A
Ion channels
transporters
pumps
3
Q
Movement with concentration gradient =
A
passive diffusion
4
Q
movement against concentration gradient =
A
active transport
5
Q
Facilitated diffusion has to what?
A
Bind to a receptor
6
Q
Active transport uses what?
A
energry
7
Q
Random movement powered by concentration gradient
A
diffusion
8
Q
Diffusion is moving toward
A
equilibrium
9
Q
Diffusion of 1 substances does not interfere with what?
A
diffusion of another substance in the same solution
10
Q
Net movement of diffusion depends on what?
A
1) concentration gradient
2) particle size
3) permeability of the compound in the barrier it is trying to cross
11
Q
The two types of diffusion are?
A
- simple/passive
2. facilitated
12
Q
Simple/passive diffusion requires a carrier protein. (T/F)
A
False (no carrier protein interaction)
13
Q
Facilitated diffusion requires what?
A
A carrier protein
14
Q
What type of diffusion can use pores or channels?
A
Simple/passive diffusion
15
Q
This type of diffusion binding occurs.
A
Facilitated Diffusion
16
Q
Diffusion of lipid-soluble molecules through a lipid bilayer depends on?
A
lipid solubility
17
Q
What molecules are highly lipid soluble & able to diffuse through lipid bilayer?
A
O2, N2, CO2, alcohols
18
Q
Rate of diffusion is dependent on what?
A
The degree of lipid solubility
19
Q
Pore channels are available for what?
A
small molecules to pass through
20
Q
_____ ______ and _____ ______ on amino acids determines selectivity of passage.
A
Pore diameter & electrical charges
21
Q
Two types of gating of protein channels?
A
Voltage gating and chemical gating
22
Q
Sodium channels & potassium channels open when?
&
This is an example of what type of gating?
A
Inside cell membrane becomes positively charged
Voltage gating
23
Q
With chemical gating what may open or close the gate?
A
Binding a molecule
24
Q
Also known as carrier-mediated diffusion
A
facilitated diffusion
25
Facilitated diffusion transport proteins sometimes called
permeases
26
Each carrier protein has a specific ____ for ____ a molecule
affinity, binding
27
The affinity for binding a molecule is measured by
Km
28
Facilitated diffusion can max out _____ if all available transport proteins are ____ to substrates
transporters, bound
29
Vmax is?
When transporters are maxed out
30
Addition of more substrate (solute) will not make facilitated diffusion go faster when it is maxed out of transporters. (T/F?)
True
31
When Vmax occurs carrier proteins are
saturated
32
Facilitated diffusion deals with movement of ____ and most ____ ___
glucose, amino acids
33
Rate of solute transport is measured by?
1/2 Vmax
34
Km =
solute concentration that will give 1/2 Vmax
35
Saturation of carrier protein reflected by leveling off of rate of transport is the?
Vmax
36
What is the transfer of liquid through a semipermeable membrane that does not allow solutes to pass?
Osmosis
37
With osmosis, water passes through _____ (____ ___) in plasma membranes
aquaporins (water pores)
38
Osmoses moves from ____ concentration to ___ concentration.
high, low
39
Net movement of water is?
Usually zero
40
Changes in solute concentration does not impact water movement (T/F)
False
41
Net movement of water occurs to area of ____ free water
less (higher concentration of solute)
42
Goal of osmosis is what?
Equalize concentration of solutes on both sides of barrier
43
Pressure applied to stop the flow of water to side of highest solute concentration is known as?
Osmotic pressure aka hydrostatic pressure
44
The hydrostatic pressure is the pressure applied to the ____ to ___ the flow of water
chamber, stop
45
Lower solute concentration ____ osmotic pressure
lower
46
What causes osmotic pressure differences on each side of the barrier?
differences in solute concentration
47
When the osmotic pressure is the same in the inside & outside of the cell?
isotonic
48
In relation to cell volume, hypotonic does what?
1. osmotic pressure is greater in cytosol
2. movement of water into the cell
3. increases cell volume
49
In relation to cell volume, hypertonic does what?
1. osmotic pressure is greater in extracellular fluid
2. movement of water out of the cell
3. cell will shrink
50
Isotonic, no volume change (T/F)
True
51
Hypotonic, cell volume ____ & may ____
increases, burst
52
Hypertonic cell volume increases (T/F)
False
53
Effects of solutions on cells: Cells with a cell wall that are hypertonic are _____?
plasmolyzed
54
Effects of solutions on cells: Cells with a cell wall that are isotonic are _____?
flaccid
55
Effects of solutions on cells: Cells with a cell wall that are hypotonic are _____?
turgid
56
Intracellular fluids primary cation
K+
57
Extracellular fluids primary cation
Na+
58
There is more what in intracellular fluid vs. extracellular fluid?
K+, Mg2+, Phospates, Amino acids and proteins
59
Intracellular fluid pH =
7.0
60
Intracellular fluid buffer
proteins
61
There is more what in extracellular fluid vs. intracellular fluid?
Na+, Ca2+, Cl- and glucose
62
Extracellular fluid pH =
7.4
63
Extracellular fluid buffer
HCO3
64
Active transport requires energry as ____ in primary active transport
ATP
65
Carrier protein in Active transport is necessary, called _____ in primary active transport
ATPases
66
The movement of ions makes ion gradient powering what?
secondary active transport
67
Types of active transport?
Primary & Secondary
68
Primary active transport pumps: P-class
Ions (Na+, K+, Ca^2+, H+)
| ex. sodium-potassium ATPase
69
Primary active transport pumps: F-class
Protons (H+)
| ex. ATP synthase in mitochondria
70
Primary active transport pumps: V-class
Protons (H+)
| Maintains low pH in lysosomes
71
Primary active transport pumps: ABC-class
Ions, drugs
| Ex. cystic fibrosis transmembrane regulator (CFTR)
72
Important feature for sodium-potassium pump it to ____ ____ ____
control cell volume
73
Without the ___ pump the cell would swell until it burst
sodium-potassium pump
74
2 subunit carrier protein for sodium-potassium pump?
a & b
75
___ binding sites for sodium on the inside of the cell
3
76
___ binding sites for potassium on the outside of the cell
2
77
Inside the cell near Na+ binding has _____ activity
ATPase
78
Highly active cells (nerves) may devote 60-70% of cells' energy to what?
sodium-potassium pump
79
___ is maintained at very low concentration in cytosol
calcium
80
2 types of Ca pumps?
1 located in the cell membrane & pumps Ca out of the cell
1 pumps Ca into endoplasmic reticulum or mitochondria
81
Both Ca pumps act as?
ATPases
82
Hydrogen pumps (aka proton pumps) are located in?
Parietal cells of gastric glands in stomach
renal tubules
83
Parietal cells of gastric glands in stomach....
secretes H+ that can combine with secreted Cl- to form HCL in stomach
84
Renal tubules functions:
Large amounts of H+ are secreted from the blood into the urine
Has a buffering function
85
Secondary active transport is broken up into?
Co-transport (symporters)
| Counter-transport
antiporters
86
Secondary active transport is not driven by ____, but instead by what?
ATP, Ion concentration gradient
87
Secondary active transport: transporters do not have what?
ATPase activity
88
Coupled transport includes?
symporters and antiporters
89
This, transports molecules in the same direction across plasma membrane
symporters
90
With symporters, Molecule 1 is move with the gradient [high to low] (T/F)
True
91
Symporters, molecule 2 is actively transporters _____ the concentration gradient
against (low to hight)
92
(Sodium-glucose transporter) Glucose is actively taken up from
gut
93
(Sodium-glucose transporter) Glucose is passively released for use by
other tissues
94
Step 1. active transport
Sodium binds carrier protein
95
Step 2. active transport
Compound binds carrier protein
96
Step 3 active transport
carrier protein releases sodium & compound inside enterocyte
97
Step 4: active transport
Sodium is pumped out of enterocyte and potassium is pumped in using ATP
98
Antiporters transport molecules in the ______ direction across plasma membrane
opposite
99
Antiporters: Molecule 1 is moved against the gradient (high to low) into the cell (T/F)
False (moved with)
100
Antiporters: Molecule 2 is what?
moved out of the cell
101
Co-transport uses
glucose and amino acids
102
counter-transport uses
calcium and hydrogen
103
All P-class pumps are phosphorylated on
aspartate
104
V-class pumps maintain what?
low pH in lysosomes
105
Glucose transport occurs by ____ ____ through most of the body & ____ ____ ____ in small intestine & kidneys
facilitated diffusion, secondary active transport
106
Active transport of glucose is used when?
Glucose concentration in cell is higher than extracellular space
107
A type of secondary active transport?
Sodium-glucose transport proteins (SGLT)
108
Where does active transport of glucose happen?
Choroid plexus
Proximal tubules of kidney
brush border epithelial cells of the small intestine
109
GLUTs transport glucose from ___ to ___ concentration
high, low
110
Facilitated transport of glucose: rate of transport varies based on:
Glucose available & number GLUT proteins
111
Facilitated transport of glucose: is able to transport...
both directions across membranes
112
GLUT2 transports
glucose, galactose & fructose out of the cell & into the portal blood
113
Insulin-Insensitive facilitated transport of glucose is found in ____ ____
most tissues
114
Insulin-insensitive facilitated transport of glucose requires...
concentration gradient of glucose
115
Insulin-insensitive facilitated transport of glucose uses
GLUT 1, 2, & 3
116
Insulin-insensitive facilitated transport of glucose is found in
RBC, WBC, liver, brain cells, etc.
117
Insulin-sensitive facilitated transport of glucose is found in
skeletal muscle, adipose tissue
118
Insulin-sensitive facilitated transport of glucose uses
GLUT 4
119
Peptide hormone secreted from the ___ of the islets of langerhans in the pancreas
B cells
120
Insulin is secreted in response to
glucose & amino acids in the blood
121
Insulin is inhibited by
epinephrine
122
How many GLUTs are there, and how many are involved with glucose transport?
14, 11
123
Insulinotropic amino acids
leucine, phenylalanin, tyrosine, arginine
124
Required to get glucose out of blood and into muscle and/or adipose tissue
Insulin
125
Insulin transports glucose, amino acids, and ____ into insulin-sensitive cells
potassium
126
Anabolic function of insulin?
Increases stores of carbs (glycogen), fat (adipose tissue) and protein (muscle)
127
Within minutes insulin stimulates
Protein synthesis, stimulates glycolysis and glyocogen synthesis, inhibites phospohorylase and glucogenic enzymes
128
Effects of insulin on Adipose tissue (increases)
- glucose entry
- fatty acid synthesis
- glycerol phosphate synthesis
- tryglyceride deposition
- activation of lipoprotein lipase,
- K+ uptake.
129
Effects of insulin on adipose tissue (decreases)
hormone-sensitive lipase
130
Effects of insulin on muscle tissues: (increases)
- glucose entry
- glycogen synthesis
- amino acid uptake
- protein synthesis
- ketone uptake
- K+ uptake
131
Effects of insulin on muscle: (decreases)
- protein breakdown
| - release of glucogenic amino acids
132
Effects of insulin on liver tissues: (increases)
- lipid synthesis
| - protein synthesis
133
Effects of insulin on liver tissues: (decreases)
ketogenesis and glucose output
134
GLUT2 located in
pancreatic beta cells
135
GLUT2 is in charge of
releasing insulin to blood
136
GLUT2 has ____ affinity for glucose
low
137
Normal blood glucose is
5mM
138
Insulin is not secreted until blood glucose is
>5 mM
139
Muscle: Insulin binds to
insulin receptor
140
Muscle: Insulin receptor ____ get recruited to the receptor
substrate 1 (IRS-1)
141
Muscle: IRS-1 begins a signal transduction cascade to tell ____ to make ____
golgi complex, GLUT4
142
Muscle: GLUT4 is translocated from golgi complex to the....
plasma membrane
143
Muscle: Glucose is able to enter muscle and ____ for use or storage
adipocytes
144
Muscle: once insulin levels decrease, GLUT4 are removed from plasma membrane by ____
endocytosis
145
Muscle: Vesicles fuse to form an organelle celled the ____
endosome
146
Type I diabetes
beta cells are destroyed (no insulin is released)
147
treatment for type I diabetes
exogenous insulin
148
type II diabetes
- insulin resistance
| - insulin regulation of GLUT2 does not function in insulin-resistance
149
type II diabetes treatment
can be reversed with diet and exercise
150
Insulin resistant muscle cell, excess inflammation (C-reactive protein [CRP]) abnormally ______ IRS-1 causing it not to signal properly
phosphorylates
151
Intestinal apical GLUT2 diabetes
insulin resistance due to high carb or high saturated fat diet. This leads to increase in GLUT2 and loss of insulin regulation
