Chapters 6,7 Flashcards
1
Q
Prokaryotic cell
A
A cell that lacks a nucleus, internal membranes, and other organelles
2
Q
Nucleoid
A
Where circular dna is contained in prokaryotic cell
3
Q
All prokaryotes have…
A
Dna, rna, a plasma membrane, cell wall, and ribosomes
4
Q
Ex prokaryote
A
Bacteria
5
Q
Eukaryotic cell
A
Cell that contains a membrane bound nucleus and other membrane bound organelles
6
Q
Ex eukaryotic cells
A
Cells of plants animals protists and fungi
7
Q
Why is eukaryotic bigger than prokaryotic
A
Bc eukaryotic cells have an internal membrane system which partitions the cell into compartments
8
Q
Most cells are how big
A
Less than 100um
9
Q
Key factor that limits the size of a cell
A
Surface area to volume ratio
10
Q
As cells increases in volume, what happens to SA
A
Decreases along w the demand for material resources increasing bc more cellular structures are needed to adequately exchange materials and energy w the environment
11
Q
By keeping the SA to volume ratio ______ cells can maintain themselves more easily
A
Higher
12
Q
A small cell size means
A
- Substances w in the cell do not need to travel as far, which allows substances to move w in the cell in a quicker and more efficent manner
- communication signals dont need to travel as far which increases the speed in which they occur
13
Q
What do internal membranes in eukaryotes do
A
Faciliate cellular processed by minimizing competing interactions and by increasing surface area where reactions can occur
14
Q
Membranes and membrane bound organelles in eurkaryotes do what
A
Localize (compartmentalize) intracellular metabolic processes and specific enzymatic reactions which increase metabolic efficiency
15
Q
Organelles that contribute to overall specialization and functioning of the cell
A
Plasma membrane
Cytoplasm
And membrane bound organelles
16
Q
Plasma membrane
A
Outer boundary of the cell that controls how easily things pass in and out of the cell (selectively permeable)
17
Q
What makes up plasma membrane
A
Lipid bilayer, composed of lipids and proteins
18
Q
Cytoplasm
A
The fluid filled region between the nucleus and the plasma membrane
19
Q
Cytoplasm consists of
A
the organelles of the cell and a semi-fluid medium called the cytosol
20
Q
Cytosol
A
Semi fluid medium in the cytoplasm
21
Q
Nucleus surrounded by
A
Nuclear envelope
22
Q
Nucleus stores
A
Hereditary info in DNA in chromosomes
23
Q
Chromosomes
A
Discrete units that dna is organized into
24
Q
Chromatin
A
Material chromosomes are made of which is a complex of proteins and DNA
25
Within the nucleus, protein synthesis is initiated by
Making mRNA from a DNA template
26
Nucleolus
A structure within the nucleus where components of ribosomes are made and assembled
27
Ribosomes
Tiny organelles that carry out protein synethesis
28
Most numerous organelle
Ribosome
29
Ribosomes are made of
Proteins and ribosomal RNA (rRNA) no membrane though
30
Where are ribosomes at
Many are free in the cytosol while others are attached to the endoplasmic reticulum
Found in both euk. And prok. Also found in mitocondria and chloroplasts
31
Endoplasmic reticulum (ER)
Network of membranes and sacs w a wide range of functions
32
Smooth ER
Called smooth er bc they do not have ribosomes on the surface
33
Function of smooth ER
Making lipids (phospholipids and steroids), metabolism of carbs, detox of drugs and poisons, and storage of calcium ions
34
Rough ER
Called rough ER bc they have ribosomes on the surface
35
Function of rough ER
To compartmentalize the cells, serves as mechanical support, functions in protein synthesis, and intracellular transport
36
How does rough ER do intracellular transport
Packages the proteins that they make into vesicles, which can then be transported throughout the cell
37
Golgi complex (or golgi apparatus)
Functions of the golgi complex include the synthesis and packaging of materials for transport
38
What makes up golgi complex
Cisternae (flattened membranous sacs)
39
Other things about golgi
Considered UPS of cell - manufactures many carbs - also produces lysosomes- works w rough ER and vesicles to synthesize and isolate proteins for secretion or for use in the cell
40
Lysosome
Membranous sac of hydrolytic enzymes that an animal cell uses in the digestion of macromolecules, the recycling of a cell's organic materials and programmed cell death (apoptosis)
41
Apoptosis
Programmed cell death
42
Lysosomes digest bacteria and are able to recycle damaged organelles
.
43
Vacuole
Membrane bound sac that plays a role in storage, intracellular digestion, and the release of cellular waste
44
Contractile vacuole
Found in freshwater protists and is used to pump excess water out of the cell
45
Rate of contraction for contractile vacuole is dependent on
The osmolarity of the water- higher the salt concentration the less the protist has to use the contractile vacuole
46
Central vacuole
large sac found in mature plant cells- allows for a large surface area to volume ratio
47
Vacuoles store
Enzymes proteins ions water wastes pigments and poisons
48
Mitochondria
Site of cellular respiration
49
What do mitochondria specialize in
Energy capture and transformation
50
How is ATP generated
By extracting energy from organic compounds (sugars, fats)
51
Where mitchondria found
Nearly all euk. cells including plants, animals, fungi, and protists
52
Where are the DNA and ribosomes of mitochondria
In the mitochondria
53
Membranes of mitochondria
Have inner and outer membrane allowing for compartmentalization
54
Cristae
Folds in the inner membrane of mitochondria
55
Cristae contains
Enzymes important to ATP production and also increases the surface area for ATP production
56
Texture of mitochondria outer membrane
Smooth
57
Chloroplast
Site of photosynthesis
58
Role of chloroplasts in photosynthesis
Capture and convert light energy into stored chemical energy in the form of organic compounds (glucose)
59
Chloroplasts produce
Small amounts of ATP
60
Chloroplasts are found
In plant cells and algae
61
Chloroplasts contain (5)
Chlorophylls and their own DNA and ribosomes and thylakoids and stroma
62
Chlorophylls
Pigments that are key light trapping molecules in photosynthesis
63
Chloroplasts are surrounded by
Double membrane that created a compartmentalized structure, which supports its function
64
Peroxisome
Membrane bound compartment that contains enzymes that transfer hydrogen from various substrates to oxygen
65
Peroxisomes break down
Fatty acids and deoxify alcohol in the liver
66
Peroxisomes produce
Hydrogen peroxide as a by product
67
Peroxisomes contain
Catalase to breakdown H2O2
68
Cytoskeleton
Network of fibers extending throughout the cytoplasm which plays a role in support motility and regulation
69
Cytoskeleton made up of
Microtubules, microfilaments, and intermediate filaments
70
What does cytoskelton do
Maintains the size and shape of the cell, helps the entire cell move and helps organelles move w in the cell
71
Microtubules
Hollow tubes that help shape and support the cell along w helping in the cell and organelle movement
72
Centrosome
Region near the nucleus that is considered the microtubule organizing center
73
Centrioles
Cylinders of microtubules that are involved in the movement of chromosomes during cell division
74
Centrioles are found
In animal cells only
75
Cilia
Short hair like extensions that use motor proteins and assist in movement
76
Flagella
Long hair like extensions that use motor proteins and assist in movement
77
Structures that contain microtubules
Centrioles
Cilia
Flagella
78
Where/How many cilia in a cell
Hundreds of cilia on the surface of the cell
79
Where/How many flagella
Only 1 flagella on the surface of the cell
80
Microfilaments
Also called actin filaments, solid rods made up of two actin filaments twisted around each other
81
What do microfilaments do
Help maintain the cell shape, help in muscle contraction and cell movement, and to form the cleavage furrow during cell division
82
Intermediate filaments
Made up of fibrous proteins called keratin, which are supercoiled into thick cables
83
What do intermediate filaments do
Reinforce the shape of the cell and anchor the organelles in place
84
Cell wall
Cell walls protect plant cells, help maintain shape, and prevent excessive uptake of water
85
Cell walls are found in what
Prokaryotes, protists, fungi, and plants
86
Plant cell walls are made of
Cellulose
87
Plasmodesmata
Open channels in the cell wall of plant cells through which cytoplasm moves connecting adjacent channels
88
What passes through the plasmodesmata
Water, solutes, proteins RNA all pass through the plasmodesmata from cell to cell
89
Gap junctions
Communicating junctions in animal cells that allow the passage of material between cells
90
What cells have a plasma membrane
All cells have a plasma membrane
91
Plasma membrane structure
Made of phospholipid bilayer
92
What causes selective permeable-ness of plasma membrane
Hydrophillic heads and hydrophobic tails
93
Fluid mosaic model
Model that describes membranes as acting more like a fluid than a solid
94
Membrane consistency:
Salad oil- phospholipids and proteins are able to move laterally along the plane of the membrane
95
Cholesterol
Steroids that are wedged between the phospholipid molecules in the plasma membrane
96
How is cholesterol a temperature buffer for the membrane
At warm: makes mem less fluid by restraining movement of phospholipids-preventing it from melting
At cold: hinders the close packing of phospholipids which prevents the membrane from freezing when the cell temp drops
97
Integral proteins
proteins that are embedded in the middle of the phospholipid membrane which aids in transport of molecules in and out of the cell
98
Where are intergral proteins
Span the hydrophobic interior and stick out into the hydrophillic exterior
99
Peripheral proteins
Proteins found on the outer surface of the phospholipid bilayer
100
Where are peripheral proteins usually
Bound to intergral proteins
101
Functions of intergral and peripheral proteins
Help transport molecules across the membrane, some work as enzymes, signal transduction (hormone reception), cell to cell recognition, join cells together, attachment to the cytoskeleton to give the cell a stronger framework
102
Carbs role in membrane
Found on the outer surface of the phospholipid bilayer, function in cell recognition
103
Glycolipids role in membrane
Combo of carbs and lipids that help cells recognize other cells
104
Glycoproteins role in membrane
Combo of carbs and proteins that help the cell recognize other cells
105
What kind of molecules pass through the easiest
Small hydrophobic (nonpolar) and uncharged
106
What type of molecules have difficulty passing the membrane
Large hydrophillic (polar) charged molecules and ions
107
Transport proteins
Proteins embedded in the membrane that help large hydrophillic polar charged particles cross the membrane
108
Are transport proteins active or passive transport
Both
109
Transport proteins are specific in the molecules they move
.
110
Passive transport
Movement of substances across the membrane without the use of energy
111
During passive transport, substances travel
From an an area of high concentration to an area of low concentration (down the concentration gradient)
112
Passive transport plays a primary role in
the import of resources and the export of wastes
113
Types of passive transport
Simple diffusion
Osmosis
Facilitated diffusion
114
Simple diffusion
Spontaneous tendency of molecules to spread out evenly into the available space
115
Ex simple diffusion
Perfume spreading out in a room
116
Osmosis
Requires water to diffuse across a semi permeable membrane
117
Facilitated diffusion
Spontaneous passage of hydrophillic molecules/ions across a membrane with the help of specific carrier proteins
118
Adv of facilitated diffusion
Allows substances to be transported across membrane faster than normal
119
Proteins used in facilitated diffusion
Channel proteins or carrier proteins
120
Hypertonic solution
Solution with a higher concentration of solutes
121
Hypotonic solution
Solution with a lower concentration of solutes
122
Isotonic solution
Solutions that have equal concentrations with no net movement of water across the membrane
123
Water moves
From a Hypotonic solution to hypertonic solution
124
Osmoregulagion
Control of water balance within a cell
125
4 states a cell can be in depending on how much water it contains
Turgid
Lysis
Flaccid
Plasmolysis
126
Turgid
When a cell contains enough water to keep it firm without bursting
127
Lysis
When a cell takes in too much water and bursts
128
Flaccid
When a cell loses water causing the cell to lose turgor or firmness
129
Plasmolysis
When a cell loses water and the plasma membrane pulls away from the cell wall
130
Active transport
Movement or pumping of molecules across the cell membrane against the concentration gradient
131
During active transport molecules move from area of what to what
Low to high
132
Sodium potassium pump
Carrier protein that actively transports 2 K+ ions into the cell and 3 Na+ ions out of the cell
133
Membrane potential
Difference in charge created by the sodium potassium pump creates a voltage across the membrane
134
Average cell voltage
-50-(-200) mV across the membrane
135
Electrogenic pump
Pump that used transport proteins and genersted a voltage across the membrane
136
Proton pump
Pump that transports hydrogen ionns (protons) across the membrane
137
Cotransport
Occurs when a substance is pumped across a membrane and does work as it diffuses back across the membrane
138
Cotransport is used in the production of
ATP
139
Endocytosis
Process by which cells ingest external fluid, macromolecules, and large proteins
140
Process of endocytosis
Part of cell membrane pinches off and the outside materials are then held in a new vesicle
141
What does endocytosis/exocytosis do to size of cell
Endocytosis: decreases cell size
Exocytosis: increases cell size
142
Phagocytosis
When the cell engulfs large particles such as bacteria or viruses
143
Pinocytosis
When the cell engulfs smaller solutes or fluids
144
Receptor mediated endocytosis
When a cell engulfs molecules into a vesicle containing proteins w/receptor sites for specific molecules
145
Exocytosis
Used to release substances from the cell
146
Process of exocytosis
Internal vesicle fuses with the cell membrane and releases its contents outside the cell
