9/9, 9/11 Class Lecture Chapter 3 Flashcards
1
Q
What is the plasma membrane composed of?
A
lipid bilayer and proteins
2
Q
Are the proteins and the bilayer still or moving
A
constantly moving, constantly changing
3
Q
what allows the proteins to move around without damage
A
fluid mosaic
4
Q
what does fluid mosaic mean
A
cell membrane recovers if damaged
5
Q
What type of role does plasma membrane have in cellular activity
A
active, dynamic role
6
Q
What does the lipid bilayer separate
A
intracellular fluid from extracellular fluid
7
Q
abbreviation with intracellular fluid
A
ICF
8
Q
abbreviation with extracellular fluid
A
ECF
9
Q
What does ICF refer too
A
within cytoplasm
10
Q
What does ECF refer to
A
everything outside of the cell
11
Q
abbreviation for interstitial fluid
A
IF
12
Q
what is the IF
A
things between and among cells, ECF that surrounds the cell
13
Q
What makes up the membrane lipids
A
Phospholipids 75%
Glycolipids 5%
Cholesterol 20%
14
Q
What are the phospholipids apart of
A
lipid bilayer
15
Q
what makes up the phospholipids heads
A
phosphate
16
Q
what are the phospholipid head properties
A
polar and hydrophilic
17
Q
what does hydrophilic mean
A
likes water
18
Q
what makes up the phospholipid tails
A
fatty acid
19
Q
what are the phospholipid tail properties
A
non polar hydrophobic
20
Q
what does hydrophobic mean
A
water-fearing
21
Q
what makes up the glycolipids
A
Lipids with polar sugar groups on outer membrane surface
22
Q
what does cholesterol do
A
Increases membrane stability
Gives structural integrity
Can’t live without
structurally essential
23
Q
what do membrane proteins do
A
Allow communication with environment, with rest of body, or with things floating around, through hormones
24
Q
how much of plasma membrane do membrane proteins make up
A
1/2
25
where do the membrane proteins live
Some float freely, move around
| Some tethered to intracellular structures, some are connected
26
what are the two types of membrane proteins
integral proteins, peripheral proteins
27
where are the integral proteins located
Firmly inserted into membrane
28
what type of regions do integral proteins have
hydrophobic and hydrophilic
29
what do the hydro properties allow for integral proteins
allows them to have reactions
30
what do integral proteins function as
as transport proteins (channels and carriers), enzymes, or receptors
31
where are peripheral proteins located
Loosely attached to integral proteins, bonds not a strong, affected by other chemicals around them
32
what organelles do peripheral proteins include
filaments on intracellular surface for membrane support
33
the function of peripheral proteins
Function as enzymes; motor means movement proteins for shape change during cell division and muscle contraction; cell-to-cell connections
34
6 functions of membrane proteins
```
Transport
Receptors for signal transduction
Attachment to cytoskeleton and extracellular matrix
Enzymatic activity
Intercellular joining
Cell-cell recognition
```
35
what are cells surrounded by
IF
36
what does IF contain
amino acids, sugars, fatty acids, vitamins, hormones, salts, waste products, some good, some bad, some neutral, some small enough to fit through the membrane
37
what does the plasma membrane allow the cell to do
Obtain from IF exactly what it needs, exactly when it is needed, allows some things in and keep some things out
Keep out what it does not need
38
property of the plasma membrane
selectively permeable
39
what does selectively permeable mean
Some molecules pass through easily; some do not
Based on size and chemical properties
Charge, polarity
40
what are the ways that substances cross the membrane
passive process
| active process
41
passive process
No cellular energy (ATP-cell energy) required, don’t use or need cell energy
Substance moves down its concentration gradient from greater to lesser
Natural process no energy needed
Molecule will passively diffuse through membrane if into or out of cells
42
active process
Energy (ATP) required,
Occurs only in living cell membranes
Does not happen in a non living world
We get our energy from the sun
43
two types of passive transport
diffusion and filtration
44
what is diffusion
greater to lesser concentration
| Collisions molecule moving around cause molecules to move down or with their concentration gradient
45
a specialized type of diffusion
osmosis
46
osmosis
diffusion of water through the membrane
47
where does filtration occur
usually across capillary walls
48
example of filtration
kidneys filter blood
49
how is the speed of diffusion decided
influenced by molecule size and temperature
50
simple diffusion
Nonpolar lipid-soluble (hydrophobic) substances diffuse directly through the phospholipid bilayer of fat-soluble molecules directly through the phospholipid bilayer
51
example of diffusion
oxygen, carbon dioxide, fat-soluble vitamins
52
what is facilitated diffusion
Certain lipophobic molecules (e.g., glucose, amino acids, and ions) transported passively for them to get in our cells they need to go through the special processes
53
what does facilitated diffusion do
Binding to protein carriers
| Moving through water-filled channels
54
what is carrier-mediated facilitated diffusion
Transport specific polar molecules (e.g., sugars and amino acids) too large for channels molecule has to fit this assistor molecule
Binding of substrate causes shape change in carrier then passage across membrane as protein helps across it changes its position which changes its shape
55
what are transmembrane integral proteins
carriers
56
what is carrier-mediated facilitated diffusion limited by
number of carriers present bc they could become saturated
57
when are the carriers saturated in carrier meditated diffusion
when they are all engaged
58
what is channel-mediated diffusion
Aqueous channels formed by transmembrane proteins
| Selectively transport ions or water
59
what are the two types of channel-mediated facilitated diffusion
leakage channels
| gated channels
60
what are leakage channels
always open
61
what are gated channels
controlled by chemical or electrical signals
| open and close
62
what is osmosis
Movement of solvent (e.g., water) across selectively permeable membrane, diffusion of water through the membrane
63
what does the water diffuse through in osmosis
plasma membrane
Through lipid bilayer
Through specific water channels called aquaporins (AQPs)
64
when does osmosis occur
Occurs when water concentration different on the two sides of a membrane
65
why type of process is osmosis
passive
| no energy required
66
what is osmolarity
Measure of total concentration of solute particles, similar to density (mass per unit volume) specific particles per solute particles
67
when does water stop moving by osmosis
```
hydrostatic pressure (back pressure of water on membrane) and osmotic pressure (tendency of water to move into cell by osmosis) equalize
opposing forces
```
68
what happens when solutions of different osmolarity are separated by membrane permeable to all molecules
both solutes and water cross membrane until equilibrium reached, both cross if they can, if they can fit through
69
what happes When solutions of different osmolarity are separated by membrane-impermeable to solutes
, osmosis occurs until equilibrium reached
70
what does osmosis cause cells to do
swell and shrink
71
what happens in osmosis when cell volume changes
disrupts cell function, especially in neurons
72
what is tonocity
Ability of solution to alter cell's water volume
73
what is isotonic
Solution with same non-penetrating solute concentration as cytosol
74
what is hypertonic
Solution with higher non-penetrating solute concentration than cytosol
75
what is hypotonic
olution with lower non-penetrating solute concentration than cytosol
76
what is metabolism
biochemical reactions inside cells involving nutrients- generalized and collective term
77
what are the two types of metabolism reactions
anabolism and catabolism
78
what is anabolism
synthesis of large molecules from small ones subsets of metabolism
79
example of anabolism
. Amino acids to proteins, break down amino acids and turn into us
80
what is catabolism
hydrolysis of complex structures to simpler one's subsets of metabolism
81
example of catabolism
proteins to amino acids
82
when does metabolism occur in our cells
throughout life
83
where does direct energy come from in metabolism
carbohydrates
84
what type of process is cellular respiration
catabolism
85
what is cellular respiration
how we get our energy
| Catabolism of food fuels --> capture of energy to form ATP in cells
86
what do enzymes shift during metabolism
shift high-energy phosphate groups of ATP to other molecules (phosphorylation)
87
what is phosphorylation
releases the phosphate group
88
what do phosphorylated molecules do during metabolism
molecules activated to perform cellular functions
89
what are the three stages of processing nutrients
Digestion, absorption, and transport to tissues
90
where does cellular processing occur
cytoplasm
91
two processes in cellular processing
synthesis and catabolism
92
what is synthesized during cellular processing
Synthesis of lipids, proteins, and glycogen
93
what happens during catabolism of cellular processing
taking glucose and splitting it apart into pyruvic acid and acetyl CoA (co enzyme or a vitamin)
94
what is the name for catabolism during cellular processing
glycolysis
95
where does oxidative breakdown occur
mitochondria
96
what breaks down during oxidative breakdown
breakdown of intermediates into CO2, water, and ATP
97
is oxidative breakdown a small process or a long process
many steps
98
CO2
waste product
99
water
metabolically waste product
100
ATP
useful product
101
what is the goal of cellular respiration
trap chemical energy in ATP
102
where can energy be stored in respiration
glycogen and fats
103
what is glycogen
energy storage, not for immediate use
104
what is oxidized and for what in cellular respiration
Oxidation of food for fuel
105
what happens during oxidation of food for fuel
Step by step removal of pairs of hydrogen atoms (and electron pairs) from substrates --> only CO2 left
106
what processes occur during cellular respiration
glycolysis, Krebs cycle (citric acid cycle), oxidative phosphorylation
107
what type of reaction is oxidation
reduction or redox reactions
108
what is oxidation
gain of oxygen or loss of hydrogen atoms
109
what happens during the oxidation-reduction reaction
Oxidized substances lose electrons and energy
Reduced substances gain electrons and energy
Catalyzed by enzymes
110
what are the enzymes during oxidation redox reactions
dehydrogenases
| oxidases
111
dehydrogenases
removal of hydrogen atoms, dehydrate
112
oxidases
transfer of oxygen
113
what enzymes require help during oxidation
vitamin B derivatives
| coenzymes
114
what is a coenzyme
(biological term for an enzyme) act as hydrogen (or electron) acceptors
115
examples of Co enzymes
NAD+ and FAD
