Test Two Module 4 Flashcards
1
Q
What is a glycoprotein?
A
A protein with a carbohydrate (sugar) group covalently attacked to it
2
Q
What is a glycolipid?
A
A lipid with a carbohydrate attached covalently
3
Q
The cells that make up living things are basically?
A
Organized collections of molecules
3
Q
Individual molecules are combined to form?
A
Complexes
4
Q
Molecular complexes can be combined to form?
A
Structures
5
Q
Structures are combined to form?
A
Intact cells
6
Q
How do you order cells, molecules, structures, and complexes, into order from INCREASING size?
A
Molecules, complexes, structures, cells
7
Q
What are the 5 tenets of cell theory?
A
- Cells are the smallest units of life that perform all vital physiological functions characteristics of life.
- Cells are the building blocks of all multicellular living things.
- All the cells from the division of preexisting cells.
- All cells are built from the same molecular components and all have essentially the same chemical and molecular composition.
- Each cell maintains homeostasis at the cellular level.
8
Q
Both the exterior and exterior of cells are ____ ?
A
Aqueous (watery)
9
Q
Cells in tissues are surrounded on the exterior by a watery medium known as the ____?
A
Extracellular fluid or interstitial fluid
10
Q
What is the interior of cells?
A
A watery medium known collectively as the cytoplasm
12
Q
What is the cytoplasm?
A
Everything inside a cell, except the nucleus.
13
Q
What is the cytosol?
A
Everything in cytoplasm except the nucleus and all other organelles (cytosol includes all dissolved smaller molecules.)
14
Q
What is an organelle?
A
Large macromolecular structures visible in electron micrographs.
15
Q
What is the plasma membrane?
A
The membrane that separates the inside and the outside of the cell. It is the cell membrane on the outside of the cells.
16
Q
The membrane surrounding the cells is always called the ____, even in plant and fungi and single celled organisms, which don’t have blood or plasma?
A
plasma membrane
17
Q
The plasma membrane is made of two main components:
A
- Membrane lipids
2. proteins
18
Q
What are membrane lipids?
A
They group together to form a barrier that separates the inside from the outside of the cell (also known as lipid bilayer, because it is always two lipid thick)
19
Q
What is a glycoprotein?
A
A protein with a carbohydrate (sugar) group covalently attached to it
20
Q
Membrane proteins typically make up __% of the molecules in a membrane?
A
50%
21
Q
In the membrane, membrane proteins perform function such as: (3)
A
- Transporting molecules across the membrane
- Anchoring one cell to another
- Acting as receptors for hormones and other signals
22
Q
Often in the membrane, the proteins are in the form of?
A
Glycoproteins
23
Q
What is the difference between cytoplasm and cytosol?
A
Cytosol is cytoplasm without orgnaelles.
24
Q
The overall shape of the cell is maintain by its _______?
A
Cytoskelton
25
What is the cytoskeleton?
A network of cytoplasmic protein fibers and tubules that provide support and structure for the cell and transport routes for the cell’s contents.
26
What are "molecular motors"?
Proteins that move down the tracks while carrying cellular material
27
Some components of the cytoskeleton act as "tracks" for what?
The movement of large structures around the cell
28
Some of the cytoskeleton protein fibers provide structure to?
Give the cell its shape
29
when a cells changes shape, it is because?
The cytoskeleton protein fibers are re-arranged
30
In addition to creating the shape of the cell, what other function can protein fibers serve?
They can act as tracks for the molecular motors that deliver material around the cell.
31
Organelles are:
Any large structures that perform a function for that cell
32
Are all organelle's bound to their own membrane's?
many, but not all are bound to their own membranes, which serve to create enclosed chambers to carry out their functions
33
_____ are the site where protein synthesis takes?
Ribosomes
34
______ are found floating free in cytoplasm and attached to endoplasmic reticulum?
Ribosomes
35
_____ are huge complexes of proteins and RNA's (no membrane)
Ribosomes
36
Ribosomes are: (3)
- Sites where protein synthesis takes place.
- Are found floating free in cytoplasm and attached to endoplasmic reticulum.
- Are huge complexes of proteins and RNAs (no membrane).
37
____ are sites where protein degradation/elimination takes place
Proteosomes
38
____ are huge complexes of proteins (no membrane)
Proteosomes
39
Proteosomes are: (2)
- Sites where protein degradation/elimination takes place.
| - Are huge complexes of proteins (no membrane).
40
_____ are sites where most of the energy currency molecules used in the cell (ATP) are generated by breaking down food molecules
Mitochondria
41
_____ consists of two membranes- its outer is smooth and the inner membrane has many folds
Mitochondria
42
Mitochondria: (2)
- Sites where most of the energy-currency molecules used the cell (ATP) are generated by breaking down food molecules.
- Consist of two membranes – its outer membrane is smooth and its inner membrane has many folds.
43
_____ consists of a network of folded membranes, creating chambers and channels
Endoplasmic Reticulum (ER)
44
_____ Subdivided into two types- rough ER and smooth ER
Endoplasmic Reticulum (ER)
45
Endoplasmi Reticulum: (2)
- Consists of a network of folded membranes, creating chambers and channels.
- Subdivided into two types – rough ER and smooth ER.
46
_____ is where proteins to be sent outside of cell are synthesised
Rough ER
47
_____ is where new membrane lipids are synthesized and Ca2+ ions are stored
Smooth ER
48
What are the dots on the rough ER that make it appear "rough"?
The ribosomes doing the synthesis
49
Why is the smooth ER considered smooth?
The lack of ribosomes
50
What happens in the smooth endoplasmic reticulum?
New lipids are synthesized and calcium ions are stored.
51
_____ consists of a stack of flattened, folded membranes, which create various unconnected chambers?
Golgi apparatus or Golgi body
52
_____ is where non-cytosolic proteins are packaged for delivery to their destination (to organelles, or for insertion into the plasma membrane, or for export out of the cell, etc.)
Golgi apparatus or Golgi body
53
Golgi body/Golgi Apparatus:
- Consists of a stack of flattened, folded membranes, which create various unconnected chambers
- Where non-cytosolic proteins are packaged for delivery to their destination (to organelles, or for insertion into the plasma membrane, or for export out of the cell, etc.)
54
_____ are membrane bound sacs containing degradative enzymes?
Lysosomes
55
_____ is where materials are sent for dismantling and degradation when they unwanted molecules, damaged organelles, or invading pathogens
Lysosomes
56
Lysosomes: (2)
- Are membrane-bound sacs containing degradative enzymes.
- Where materials are sent for dismantling & degradation when they unwanted molecules, damaged organelles, or invading pathogens.
57
_____ consists of two membranes (called the nuclear envelope) with large protein complexes that serve as nuclear pores to allow material in and out
Nucleus
58
_____ is where DNA, the genetic material is stored and maintained?
Nucleus
59
Nucleus: (2)
- Consists of two membranes (called the nuclear envelope) with large protein complexes that serve as nuclear pores to allow material in and out.
- Where DNA, the genetic material, is stored and maintained.
60
_____ are membrane bound extensions of the cells exterior plasma membrane?
Cilia
61
____ contain protein fibers that move, thus moving each cilium with them?
Cilia
62
_____ on a single cell move materials along the cell's surface?
Cilia
63
Cilia: (3)
- Are membrane-bound extensions of the cell’s exterior plasma membrane.
- They contain protein fibers that move, thus moving each cilium with them.
- Cilia on a single cell move in unison and can move materials along the cell’s surface.
64
_____ are short membrane bound extensions of the cells exterior plasma membrane?
Microvilli
65
_____ contain immobile protein filaments that maintain their structure?
Microvilli
66
_____ serve to increase surface area on cells so more materials can be absorbed at the same time?
Microvilli
67
Microvilli: (3)
- Are short membrane-bound extensions of the cell’s exterior plasma membrane.
- They contain immobile protein filaments that maintain their structure.
- They serve to increase surface area on cells so more materials can be absorbed at the same time.
68
What is diffusion?
The spontaneous spread of a substance from areas of high concentration to areas of low concentration
69
When molecules are left on their own they do what?
they move randomly
70
In areas of high concentration, where there are a lot of molecules, what do the molecules do?
The molecules bump into each other more frequently, bumping them into less crowded areas. Which causes the substance to spread out until all the molecules have evenly spread out over the space available
71
What are the molecules always doing?
Moving
72
Diffusion is said to cause molecules to spontaneously do what?
Move down their concentration gradient
73
The direction of spontaneous movement is always?
down the concentration gradient
74
Diffusion continues until?
A substance is evenly spread out
75
During diffusion, once there is no more concentration gradient there is no more?
net movement. Individual molecules continue to move randomly, but random movements of some molecule in one direction are balanced by random movements of another molecule in the opposite direction – and the whole stays evenly spread out.
76
Diffusion down the concentration gradient is always _____ ; but various factors can effect how rapidly it occurs
Spontaneous
77
Higher temperature can cause diffusion to?
Diffuse faster
78
Larger surface can cause diffusion to?
Diffuse faster
79
Higher gradient can cause diffusion to?
Diffuse faster
80
Smaller particles can cause diffusion to?
Diffuse faster
81
A solid will diffuse the?
slowest
82
A liquid will diffuse?
faster
83
A gas will diffuse the?
fastest
84
osmosis is simply the?
diffusion of water
85
Diffusion of water (osmosis) is only notable when there is?
a barrier or membrane between two volumes of water.
86
All cells membranes (plasma membrane, mitochondrial membrane, nuclear envelope, etc) are _____?
selectively permeable
87
What is a selectively permeable membrane?
A membrane across which some molecules can across, but others cannot.
88
_____ is one of the molecules that can always freely cross all cell membranes, of every cell type and every organelles type, so osmosis is always a consideration with cells
Water
89
Osmosis/diffusion of water occurs _____ down the concentration gradient of water.
Spontaneously
90
In which direction does osmosis ALWAYS occur?
Down the water concentration gradient.
91
______ will have the highest concentration of water – the water molecules will fill all the available space
Pure water
92
If there are any _____ in the water, they will take up space, so fewer water molecules will be present, and the water concentration will be lower than pure water
dissolved substances
93
Any time you have different concentrations of a dissolved material across a cell membrane: (2)
1. The side with the higher concentration of dissolved material will have the dissolved material diffuse out of that side if it can.
2. The side with the higher concentration of dissolved material will have water diffuse into that side if it can
94
Cell membranes are selectively permeable, so there will be situations where there is a solute at different concentrations across a membrane that is?
- not allowed across the membrane – only water will be able to diffuse across.
- This can cause the side with the higher solute concentration/lower water concentration to increase in volume! (And the other side to decrease.)
- The movement of water that changes the volumes of both sides of the membrane can be prevented if a force is applied to the growing side.
- This will force the water molecules back through the membrane, against their concentration gradient.
- Note, forcing water back through the membrane is not spontaneous. It required a force.
95
What is osmotic pressure/osmotic potential?
The force of a concentration gradient of water that equals the force (hydrostatic pressure) needed to block osmosis across a selectively permeable membrane.
96
What is the concept of using pressure to force water to move against its concentration gradient, enough to undo whatever diffusion of water would otherwise have happened spontaneously?
Osmotic pressure or osmotic potential
97
The _____ the osmotic pressure/potential of a solution, the more likely water will diffuse into that solution
Greater
98
Another term for osmotic pressure/osmotic potential?
Tonicity
99
The greater the osmotic pressure the _____ the tonicity?
higher
100
We just use ____ as a comparison for comparing a solution on one side of a membrane to the solution on the other side of the membrane.
Tonicity
101
Usually, we use tonicity to compare?
compare the solution outside of a cell to the cytoplasm inside a cell.
102
What is the relationship between osmotic pressure and tonicity?
The higher the osmotic pressure, the higher the tonicity
103
What is a isotonic solution?
A solution that does not cause osmotic flow of water across the membrane. (same)
104
When the solution outside the cell is isotonic: (3)
- Solutes in the solution outside the cell are at equal concentration as solutes in cytoplasm inside cell (so there are equal water concentrations both inside and outside cell).
- The solution around the cell causes water to neither enter nor leave the cell.
- As a result, the cell neither shrinks nor expands in an isotonic solution.
105
What is a hypotonic solution?
A solution outside of a cell or container that causes osmotic flow of water across a membrane out of the hypotonic solution (into the cell/container).
106
When the solution outside the cell is hypotonic: (3)
- The solution outside the cell has less solutes (more water) than the cytoplasm inside cell.
- The solution outside the cell causes water to enter the cell.
- As a result, the cell expands in a hypotonic solution.
107
What is a hypertonic solution?
A solution outside of a cell or container that causes osmotic flow of water across a membrane into the hypertonic solution (out of the cell/container).
108
When the solution outside the cell is hypertonic:
- The solution outside the cell has more solutes (less water) than cytoplasm inside cell.
- Solution outside the cell causes water to leave the cell.
- As a result, the cell contracts in a hypertonic solution.
109
To maintain homeostasis, a cell needs to: (2)
- Allow certain compounds in and other compounds out.
| - And the cell needs to regulate when these molecular movements in and out occur.
110
Membrane lipids act as _____ to most molecules, but not all.
barriers
111
Non-hydrophobic molecules cannot cross the barrier made by _____?
Membrane lipids
112
Channels: (2)
- Membrane proteins that provide little more than a tunnel through which molecules can diffuse.
- Transport is always passive, which means the molecules always travel down the molecule’s concentration gradient.
113
What happens in passive transport?
Molecules always move down the concentration gradient
114
Gated Channels: (4)
- Membrane proteins that provide little more than a tunnel through which molecules can diffuse, but the tunnel has a barrier or gate that can be opened or closed.
- The cell can regulate when the barrier or gate is open or shut .
- When barrier/gate is open, transport is always passive, down the molecule’s concentration gradient.
- When barrier/gate is closed, nothing is transported through it.
115
Pumps: (2)
- Membrane proteins that use up energy in the form of ATP (the energy currency of the cell) to move a molecule in the direction it would not diffuse spontaneously
- Transport by pumps is always active, up the molecule’s concentration gradient
116
What happens in active transport?
Any movement of molecules across a cell membrane that is only ever against (up) a concentration gradient
117
carrier proteins: (3)
- Membrane proteins that bind a specific molecule on one side of a membrane and release it on the other side
- Transport by carriers can be passive, and only move molecules down their concentration gradients; it depends on the specific carrier
- Transport by carriers can also be active, and always move molecules against their concentration gradient; it depends on the specific carrier
118
Membrane transporter proteins that are always passive transport?
Channels (even gated channels)
119
Membrane transporter proteins that are always active transport?
Pumps
120
Membrane transporter proteins that can be active transport or passive transport?
Carrier proteins
121
A cell membrane is _____ because its membrane proteins select which molecules can cross the membrane under what circumstances.
selectively permeable
122
A _____ usually allows only one molecule in its tunnel like center.
specific transporter protein
123
The _____ channel only lets water across, no other molecules.
aquaporin
