Test 2 ACTUALLY Flashcards
(139 cards)
1
Q
Magnification
A
Ration of an objects to its actual size
2
Q
Resolution
A
Measure of an images clarity
3
Q
Contrast
A
How different one structure looks from another in terms of brightness
4
Q
Light microscope
A
Uses light from illumination. Was first invented in 1590
5
Q
Electron microscope
A
Uses an electron beam for illumination
6
Q
Transmission electron miscrscopy (TEM)
A
Beam of electrons transmitted through thin slide of the sample
7
Q
scanning electron microscopy (SEM)
A
An electrons transmitted through thin slide of the sample
8
Q
Cell fractionation
A
The breaking up of cell vía centrifugación,in order to allow scientist to better study sub cellular structures
9
Q
Plasma (cell) membrane
A
Barrier surrounding each cell
10
Q
Cytoplasm
A
Gel-filled region including everything inside the plasma membrane
11
Q
Chromosomes
A
Tightly bound bundle of DNA, containing genes
12
Q
Ribosomes
A
Non-organelles involved in protein synthesis
13
Q
Nucleotide
A
Region where genetic material is likely to be found
14
Q
Domain Bacteria
A
Abundant in everyday temperature environments
15
Q
Domain Archea
A
Less common, found in extreme environmental conditions
16
Q
Cell wall
A
Protective structure found outside the cell membrane in most prokaryotes and some protists, as well as in fungi and in plants. It helps to maintain the shape of cells and prevents excessive amounts of water from getting into the cell. It’s made of cellulose and is held together with pectin polysaccharides
17
Q
Organelle
A
Membrane-bound compartment with its own unique structure and function within a cell
18
Q
Nuclear envelope
A
Double membrane enclosing the nucleus
19
Q
Nuclear pores
A
Providing passage ways for diffusion of small molecules
20
Q
Nucleolus
A
Area is die the nucleus where the ribosomes are made. This region will be bigger in cells with active gene transcription
21
Q
Endomembrane system
A
Network of varied membranes including nuclear envelope, the endoplasmic reticulum, the Golgi apparatus, lysosomes, vacuoles, and vesicles
22
Q
Vesicles
A
Membrane enclosed sacs
23
Q
Rough endoplasmic reticulum
A
studded with bound ribosomes and continuous with nuclear envelope and involved with protein synthesis and sorting but also capable of making phospholipids
24
Q
Smooth endoplasmic reticulum
A
lack ribosomes and involved with the detoxification of drugs and poisons, carbohydrate metabolism, calcium ion balance maintenance, and synthesis and modification of lipids
25
Endoplasmic reticulum
Large network of membranes that form flattened, fluid-filled tubules or compartments used isn’t he manufacture of new molecules
26
Golgi apparatus
Center of cell product processing, sorting, and shipping. Cells are sent to the golgi through the ER and the cis side takes in the materials. Inside the cisternae the cell products and sent through the the trans side
27
Lysosomes
Organelles that contain acid hydrolase that performs hydrolysis and creates a space where cells can digest macromolecules safely
28
Phagocytosis
A type of endocytosis in which large particulate substances of smaller organisms are take up by the cell
29
Pinocytosis
A type of endocytosis in which a cell ingests extra cellular fluid and it’s dios solved solutes
30
Auotphagy
Lysosomes use their hydrolysis enzymes to recycle the cells own organic material
31
Food vacuoles
Formed by phagocytosis of materials in a cell environment, found in protist and human white blood cells and will eventually fused with lysosomes
32
Contractile vacuoles
Are found in freshwater protists and are used from expelling excess water
33
Large central vacuoles
Are found in plant cells for storage and cell support. Makes up most of the plant cell
34
Mitochondria
The primary role is to make ATP via cellular respiration but also involved in the synthesis, modification, and break down of several types of cellular molecules
35
Chloroplasts
Perform photosynthesis by capturing light energy and using it synthesize organic materials such as glucose
36
Peroxisomes
Organelles that generate and degrade hydrogen peroxide as part of detoxification reactions
37
Cytoskeleton
Network of Three different types of protein fibers found throughout the cytoplasm. the three main types of fibers are microtubules, intermediate filaments, and microfilaments
38
Microtubules
The largest fibers. long hollow cyndrical structures with dynamic instability. Involved in mitosis and meiosis. Cilia and flagella are both part of microtubules
39
Intermediate filaments
Mid-sized fibers. Rope like and religo ley stable. They reinforce cell shape and fix organelles to a specific location
40
Microfilaments
The smallest fiber. Long and thin fibers that have a dynamic cell stability( cell support and attachment) These are also referred to as actin filaments
41
Cilia
Often shorter than flagella and tend to cover all parts of sum part of the cell
42
Flagella
Usually longer cilia and are typically present in singles or pairs
43
What is similar between both cilia and flagella
They both have the same internal structure
44
Motor proteins
Category of cellular proteins that use ATP as a source of energy to promote movement. They have a head, hinge, and tail that they use to walk across the cell
45
Plasmodesmata
Cell wall channels that link the cytosol of neighboring plant cells, allowing material to pass between cells. this is only in plant cells
46
Tight junctions
Make a tissue watertight by providing connecting between close neighboring cells
47
Desmosomes
Keeps one cell attached to the other like buttons. They are not water tight and there are gaps in between like buttons
48
Which type of microscope gives scientists the highest level of magnification and resolution
SEM microscope
49
What is the difference between transmission electron microscopy and scanning electron microscopy
The scanning electron microscopy is the bets microscope because it is able to excite the the electrons to make a 3D image of the thing being looked at. The electron microscope cannot make a 3D image
50
During the process of cell fractionation, which “size class” of sub cellular structures will form pellets first
Larger sub cellular
51
Similarities and differences between Prokaryotes and Eukaryotes
Prokaryotic cells are very primitive and do not have a nucleus. Eukaryotic cells have membrane bound organelles while prokaryotic cells have organelles that float around in the cytoplasm
52
Main features of a Prokaryotic cell
No nucleus, no membrane bound organelles, small than Eukaryotic cells, has tail
53
How does the presence of organelles in. Ell sof eukaryotes always many of them to afford to be multicellular
More efficient use of time, energy, and cell materials due to division of labor
54
How does the presence of a plasma membrane ensure the maintenance of homeostasis on a cell
It decides what can come in and out of the cell at any time
55
What do the nuclear pores do
Allow materials such as mRNA and ribosomes to easily move from the nucleus into the endomembrane system
56
Where are ribosomes made
The nucleolus
57
How are vesicles used in the endomembrane system
They are used to package cell for intracellular transport or extra cellular export
58
What are the structural differences between the rough and smooth ER
The rough ER contains ribosomes as is involved in protein synthesis. The smooth ER does not contain ribosomes and involves the detoxification of drugs
59
What do lysosomes contain that help them break down a wide variety of substances
Acid hydrolase that performs hydrolysis
60
why are mitochondria and chloroplasts referred to as semi autonomous organelles
Because they are almost a small nucleus are thought to evolved from one cell eating another
61
What toxic by product do the demolition reactions occurring in a Peroxisomes create, and how does a Peroxisomes deal with this by product
The reactions create hydrogen peroxide, which is broken down by the Peroxisomes into water and oxygen gas thought the use of catalase
62
Be able to differentiate between descriptions cilia and flagella
Flagella is bigger than cilia and are only present by itself for with one other while cilia is smaller and mostly on larger groups
63
what are the three wats ATPcreate move to within a cell
By “walking” along a cytoskeleton fiber, by remaining stationary while cytoskeleton fiber is “pulled/fed along” beneath it, and by causing a cytoskeleton fiber to bend/flex
64
What are the three figures a plant cell has that an animal cell doesn’t
Large central vacuole, cell wall, chloroplasts
65
How are animal cells held in place
By ECM primarily composed by collagen fibers
66
Phospholipid bilayer
The composition of the plasma membrane studded with proteins
67
Amphipathic
Having both a hydrophilic and hydrophobic region
68
Selectively permeability
Some substances travel across it much more easily than others
69
Fluid mosaic model
Aggregate mosaic of lipid, protein, carbohydrate molecules resembling a fluid because the lipids and protein can move relative to each other with in the membrane
70
Peripheral proteins
non covalently bound to regions of integral proteins that project from the membrane, or bound to the polar head of phospholipids
71
Integral protein
Penetrate the hydrophobic core of the lipid bilayer
72
Glycolipid
Crabohydrate bound to a lipid
73
Glycoprotein
Carbohydrate bound to a protein, more common
74
Diffusion
The spontaneous tendency of any substance to spread out evenly across all available space
75
Concentration gradient
Difference in concentration
76
Passive transport
Does not require energy input and involves diffusion of a solute to achieve equal distribution on either side of the membrane barrier
77
Passive transport
Does not require energy input and involves diffusion of a solute to achieve equal distribution on either side of the membrane barrier
78
Passive diffusion
Does not require energy input and involves diffusion of a solute to achieve equal distribution on either side of the membrane bilayer
79
Facilitated diffusion
Diffusion of a solute through a membrane with the aid of a transport protein
80
Active transport
Requires an energy input and involves moving a solute moving “up its concentration gradient”
81
Osmosis
Diffusion of water across a selectively mergeable membrane
82
Hypertonic
Region with higher concentration of solute
83
Hypotonic
Region with lower concentration of solute
84
Turgor pressure
Water pressure present inside a plant cell that pushed the plasma membrane against that cell wall
85
Channel proteins
Form open passageways to allow the diffusion of ions or molecules across the membrane
86
Ion channels
Allow passage across membrane for ions, often gated
87
Aquaporins
Channels for water
88
Carrier proteins
Perform a conformational change to transport solute
89
homeostasis
living cells maintain a relatively constant internal environment different from their external environment
90
primary active transport
uses ATP as the energy source (as an ATP-driven pump) to transport solute
91
secondary active transport:
uses a pre existing concentration gradient to drive transport of solute
92
sodium-potassium pump:
actively transport Na+ and K+ against their gradients by using the energy from ATP hydrolysis (breakdown)
93
uniporter
single molecule or ion is moved
94
cotransporter (symporter
two or more ions or molecules are transported in the same direction
95
antiporter
two or more ions or molecules are transported in opposite directions
96
exocytosis
cell products are packaged into vesicles for export and excreted/released into the extracellular environment
97
phagocytosis
“cellular eating” of whole pieces of debris or arts of other cells
98
pinocytosis
“cellular drinking” of fluid
99
receptor-mediated endocytosis:
involves the entry of large particles that require recognition by a cell membrane receptor
100
signal transduction pathway:
process by which a chemical signal on a cells surface is converted into a specific cellular response
101
reception stage:
occurs when a signal molecule binds to a cellular protein
102
transduction stage
after binding with a signal molecule, a change occurs in the receptor protein that triggers a signal transduction pathway within a cell
103
response stage:
the transducer signal triggers specific cellular activities
104
paracrine signaling:
involves local chemical signals secreted by one cell and received by neighboring cels
105
synaptic signaling:
involves local chemical signals produces by one nerve cell and received by another nerve cell
106
hormones
involves long-distance chemical signal produced but the endocrine system
107
G protein-coupled receptors:
G protein-coupled receptors:
108
phosphorylation/dephosphorylation:
the transfer/removal of phosphate groups from ATP to proteins
109
protein kinases
enzymes that add phosphate groups from proteins
110
protein phosphatases:
enzymes that remove phosphate groups to proteins
111
wha is the major component of any biological membrane
phospholipid
112
which part of a phospholipid faces outward towards the watery environment
head
113
what produces energy for flippase to move lipids from one side of a membrane bilayer to the other
ATP
114
Will a membrane be more fluid if the fatty acid tails of its lipids are longer or shorter? Will a membrane be more fluid if single bonds or multiple bonds are present in the fatty acid tails of its lipids?
The shorter the fatty acid the more fluid it will be because the fatty acids will interact with each other less. The more the tails, the harder it is as well to interact, which makes the bilayer more fluid
115
What does cholesterol do for a cell
insulate a cell from extreme temps
116
how do the hydrophilic and hydrophobic regions of proteins determine how they can interact with cell membranes
The peripheral proteins bound to the polar header of the phospholipids while the integral proteins penetrate the hydrophobic core of the lipid bilayer
117
How is the movement of some membrane proteins restricted?
Cholesterol reduces membrane fluidity
118
When looking at a TEM image of a cell membrane cross-section, why do the hydrophobic centers of lipid bilayers look “empty,” while their hydrophilic “edges” appear dark?
The dye binds tightly with the polar heads but doesn’t effect the tails at all
119
Where are the lipids needed for cell membranes synthesized in a cell?
(smooth ER)
120
Where are the proteins needed for cell membranes synthesized?
(rough ER)
121
What properties make it more likely that a molecule will move easily across a membrane? What properties make it less likely to be able to move across?
Small, uncharges, or inside some sort of vesicle make it easies for molecules
122
Why do the processes of diffusion and osmosis occur?
Remember that the Second Law of Thermodynamics dictates that all substances tend to spread out evenly in a given environment because the universe tends toward entropy/chaos.
123
Why are plant cells not able to lyse? What does turgor pressure provide for a plant?
Turgor pressure is pressure that is always against a plant cell wall that keeps it from lysing (exploding)
124
Why do ions and water molecules require a protein channel to move across a membrane?
Ions are charged, which makes it harder for them to cross the membrane
125
What makes carrier proteins different from channel proteins?
Carriers are shape specific to let specific molecules across the membrane. Channels are just holes in the membrane that allow for things to pass through
126
Why is it important to control movement of molecules across a membrane?
Homeostasis cannot be kept if there are too little or too much of certain things
127
What is the difference between primary and secondary active transport?
Uses ATP to transport solute. Uses concentration gradient to transport solute
128
How does the sodium-potassium pump provide a good example of a primary transport antiporter?
It is an ATP-driven pump moving 2 substances in opposite directions.
129
Why is it also an electrogenic pump?
(It is moving positively charged ions in unequal numbers to opposite sides of a cell membrane.)
130
When very large molecules/particles/droplets are moved across a membrane via exocytosis or endocytosis, what “encapsulates” the material being moved?
Vesicles
131
Understand that the sequence of the three stages of a signal transduction pathway would be:
Reception stage where a ligand binds to a cellular protein, then transduction that occurs after the ligand has bonded that triggers a transduction pathway within a cell, lastly the response stage when the signal triggers specific cellular activities
132
Which of the types of signaling that we discussed (direct cell contact, paracrine signaling, synaptic signaling, or hormone signaling) is the only one that would work across long distances in a multicellular organism?
Hormones
133
Be able to recognize written descriptions of examples of cell membrane receptors (i.e. G protein-coupled receptors, tyrosine-kinase receptors, or ligand-gated ion channels embedded in outer cell membranes that are binding incoming chemical signals) vs. intracellular receptors (steroid or thyroid hormones that diffuse through cell membrane and then bind to receptors in the cytosol or nucleus).
The G- protein is like an on off switch for signaling molecules. When its bound to GDP its inactive and when its bound to GTP its active. The tyrosesn kinase receptor transfers phosphate groups from ATP to multiple tyrosine amine acids in order to allow their binding with more than one relay protein. Ligand gated ions is an ion channel guarded by ligands. Steroid and thyroid hormone signaling is hydrophobic chemical signals that pass through the cell membrane before being bound by cytosol to nucleus receptors
134
Why is the use of signal transduction pathways so beneficial to cells?
It produces an amplification of any incoming signals, and also allows cells to have a large degree of specificity and control over how they respond to a chemical signal.
135
What do glycolipids and glycoproteins do for the cell
often help receive signals or serve as markers on the surface of cells to provide a recognition flag for other cells to see
136
Land and cell membrane binding is...
ALWAYS SHAPE SPECIFIC
137
what is a common way to activate/deactivate relay proteins that are involved in a signal transduction pathway
phosphorylation/dephosphorylation
138
different type of cells receiving identical incoming cells are likely to...
have completely different responses due to variation that exists in their individual signal transduction pathways
139
Homeostasis
Living cells maintain a relatively constant internal environment different from their external environment
