Cells Flashcards
(119 cards)
1
Q
have no true nucleus
A
prokaryotes
2
Q
Where can the DNA be found in prokaryotes?
A
Nucleoid
3
Q
have nuclues
A
Eukaryote
4
Q
- spherical structure found in the cell’s nucleus whose primary function is to produce and assemble the cell’s ribosomes
- dark-staining body
A
Nucleolus
5
Q
Who examined a thin slice of cork tissue
A
Robert Hooke (1665)
6
Q
What did Robert Hooke observe in the thin slice of cork tissue?
A
honeycombed compartments
7
Q
What did Robert Hooke called those honeycombed compartments he observed?
A
cellulae (small rooms)
8
Q
Who proposed the first two statements of the cell theory in 1838-1839?
A
Matthias Schleiden and Theodor Schwann
9
Q
concluded that all plant parts are made of cells
A
Matthias Schleiden
10
Q
concluded that all animal tissues are made of cells
A
Theodor Schwann
11
Q
What are the three (3) principles of cell theory?
A
- All organisms are composed of one or more cells
- Cells are the smallest living things
- Cells arise only by division of a previously existing cell
12
Q
self-organized, endogenously ordered, spherical collection of lipids proposed as a stepping-stone toward the origin of life.
A
Protocell
13
Q
What do plant cells have that animal cells do not have?
A
- cell wall
- chloroplasts
- large central vacuole
14
Q
Cell wall are made up of __.
A
cellulose (most abundant carbohydrate)
15
Q
Organelles responsible for photosynthesis
A
chloroplasts
16
Q
internal membranes of chloroplasts and cyanobacteria that provide the platform for the light reactions of photosynthesis
A
Thylakoid
17
Q
- stores nutrients and water on which a cell can rely for its survival.
- also stores wastes from the cell to prevent contamination
A
Large central vacuole
18
Q
What do animal cells have that plant cells do not have?
A
- lysosomes
- centrioles
- flagella (though present in some plant sperm)
19
Q
- membrane-bound cell organelle that contains digestive enzymes
- break down excess or worn-out cell parts
- may be used to destroy invading viruses and bacteria
A
Lysosomes
20
Q
help to arrange the microtubules that move chromosomes during cell division
A
Centrioles
21
Q
microscopic whip-like structure that helps to propel a cell through liquids
A
flagella
22
Q
- provides pigmentation to skin, eyes, and hair.
- absorbs harmful UV (ultraviolet) rays and protects cells from sun damage
A
Melanin
23
Q
- command center of the cell
- directs all of the cell’s activities
A
Nucleus
24
Q
What does the nucleus store?
A
hereditary information
25
What surrounds the nucleus?
Nuclear envelope (has pores)
26
- large complex of proteins that allows small molecules and ions to freely pass, or diffuse, into or out of the nucleus
Nuclear pore
27
extensive system of interior membranes that divides the cell into compartments
Endomembrane System
28
What does the endomembrane system consists of?
1. Endoplasmic Reticulum
2. Golgi Complex
3. Lysosomes
4. Peroxisomes
29
internal membrane system creating channels and membrane-bound vesicles
Endoplasmic Reticulum (ER)
30
What are the two (2) distinct regions that the Endoplasmic Reticulum consists?
1. Rough Endoplasmic Reticulum (ER)
2. Smooth Endoplasmic Reticulum (ER)
31
- studded with ribosomes
- involved in protein synthesis
Rough Endoplasmic Reticulum (ER)
32
- embedded with enzymes
- involved in lipid and carbohydrate synthesis
Smooth Endoplasmic Reticulum (ER)
33
Where does the ER transport the molecules it synthesizes to?
Golgi Complex
34
- flattened stack of membranes that are scattered throughout the cytoplasm
- collects, packages, modifies, and distributes molecules
Golgi complex
35
carry cargo from the endoplasmic reticulum to the Golgi
Transport vesicles
36
- consists of the materials that have to be excreted from the cell
- these may carry soluble proteins, peptides, or neurotransmitters
Secretory Vesicles
37
- contain enzymes that break down macromolecules
- arise from the Golgi complex
Lysosomes
38
The lysosomes function in intracellular digestion of:
- worn-out cellular components
- substances taken into cells
- resulting material is then recycled
39
- arise from the Endoplasmic reticulum
- contain two (2) sets of enzymes
Peroxisomes
40
What are the two (2) sets of enzymes that are found in peroxisomes?
- One set is found in plants
- Other set is found in animals
41
What does the enzyme contained in peroxisomes that are found in plants do?
converts fats to sugars
42
What does the enzyme contained in peroxisomes that are found in animals do?
detoxifies various harmful molecules
43
What are the two (2) organelles that contain DNA?
1. Mitochondria
2. Chloroplasts
44
Powerhouse of the cell
Mitochondria
45
How do mitochondria extract energy from organic molecules?
Through oxidative metabolism
46
process by which ATP synthesis is coupled to the movement of electrons through the mitochondrial electron transport chain and the associated consumption of oxygen
Oxidative phosphorylation
47
Like bacteria, mitochondria:
1. Possess circular DNA (plasmid)
2. Divide by simple fission
48
folds in the inner membrane of a mitochondrion that greatly increase the surface area
Crista
49
contains the DNA of the mitochondrial genome and enzymes of the tricarboxylic acid (TCA) cycle (AKA Krebs cycle)
Matrix
50
proposes that mitochondria and chloroplasts arose by symbiosis from ancient bacteria
The Endosymbiotic Theory
51
- the Interior Framework of the Cell
- dense network of protein fibers
The Cytoskeleton
52
What does the cytoskeleton do?
- supports the shape of the cell
- anchors organelles
53
What are the three (3) different kinds of protein fibers?
1. Microfilaments
2. Microtubules
3. Intermediate filaments
54
What proteins make up microfilaments?
Actin (contractile protein)
55
What proteins make up microtubules?
Tubulin (globular protein)
56
- fine, thread-like protein fibers
- associated with the protein myosin
- can also carry out cellular movements
microfilaments
57
What are the cellular movements that microfilaments can carry out?
- gliding
- contraction
- cytokinesis
58
- cylindrical tubes
- act as scaffold to determine cell shape
- provide a set of "tracks" for cell organelles and vesicles to move on
- form the spindle fibers for separating chromosomes during mitosis
microtubules
59
- about 10nm in diameter
- provide tensile strength for the cell
intermediate filaments
60
- superfamily of proteins which bind actin
- hydrolyze ATP
- transduce force
Myosin
61
anchor and assemble microtubules
centrioles
62
centrioles are not found in __ __ and __
higher plants and fungi
63
centrioles may have originates as __ __
symbiotic bacteria
64
__ __ is tied up with cytoskeleton
Cell movement
65
Which protein fibers are tied up with cell motion?
- microfilaments
- microtubules
66
Changes in the shape of microfilaments:
- enable some cells to change shape quickly
- allow some cells to crawl
- cause animal cells to divide
67
- consists of a 9+2 arrangement of microtubules
flagella and cilia
68
How are flagella and cilia anchored in the cell?
basal body
69
long and few in number
flagella
70
short and numerous
cilia
71
microtubule-based organelles that assemble cilia and flagella
basal bodies
72
motor protein that moves vesicles to the cell's periphery
kinesin
73
motor protein that moves vesicles to the cell's interior
dynein
74
What are the functions of vacuoles in plants?
- store dissolved substances
- can increase the cell's surface area
75
What is the function of vacuoles in protists?
pump excess water
76
What do you call the vacuoles found in protists?
contractile vacuoles
77
- helps cells attach to, and communicate with, nearby cells, and plays an important role in cell growth, cell movement, and other cell functions
extracellular matrix
78
what is the extracellular matrix composed of?
mixture of glycoproteins secreted by animal cells
79
links extracellular matrix (ECM) to the cytoskeleton
Integrin
80
encases all living cells
cell membrane
81
the basic structure of cell membrane is represented by the ___
fluid-mosaic model
82
what components make up the plasma membrane according to the fluid mosaic model?
- phospholipids
- proteins
- cholesterol
- carbohydrates
83
What is the structure of a phospholipid?
- One polar (hydrophilic) head of phosphate moiety
- Two nonpolar (hydrophobic) tails of fatty acids
84
What are the two (2) main types of proteins within the membrane?
1. Cell-surface proteins
2. Transmembrane (aka transport) proteins
85
- project from the surface of the membrane
- act as markers or receptors
cell-surface proteins
86
- extend all the way across the bilayer
- provide channels in and out of the cell
transmembrane (transport) proteins
87
helps with the integrity of the membrane
cholesterol
88
some molecules can diffuse across the lipid bilayer but other cannot
semi-permeable cell membrane
89
What are the things that can pass through on their own by simple diffusion across the semipermeable cell membrane?
small, uncharged particles
90
What are the things that can't diffuse on their own across the semipermeable cell membrane?
- large molecules
- charged particles
- anything being moved against concentration gradient
91
the movement of molecules down their concentration gradient
diffusion
92
Equal concentration
equilibrium
93
Diffusion of water through a semipermeable membrane
Osmosis
94
contains higher concentration of solutes than the cell
hypertonic solution
95
contains lower concentration of solutes than the cell
hypotonic solution
96
contains equal concentration of solutes as the cell
Isotonic solution
97
Water that does not have solutes
Free water molecule
98
What is formed in the process of transforming a dissolved substance into an insoluble solid from a super-saturated solution?
Precipitate
99
Movement of water into a cell creates __ __
osmotic pressure
100
occurs when a cell bursts due to an osmotic balance that has caused excess water to diffuse into the cell
Cytolysis or osmotic lysis
101
occurs when a cell shrinks due to a hypertonic environment
Plasmolysis
102
discharge of material from vesicles at the cell surface
exocytosis
103
the plasma membrane envelops particles and brings them into the cell interior
endocytosis
104
What are the three (3) major forms of endocytosis?
1. Phagocytosis
2. Pinocytosis
3. Receptor-Mediated Endocytosis
105
engulfment of particulate material
phagocytosis
106
engulfment of liquid material
pinocytosis
107
- form of endocytosis in which receptor proteins on the cell surface are used to capture a specific target molecule
- highly specific and very fast
receptor-mediated endocytosis
108
Cell membranes have __ __. Contain protein channels that allow only certain molecules to pass
Selective permeability
109
allows molecules to pass through open channels in either direction
selective diffusion
110
if the ion fits the pore, it goes through
ion channels
111
net movement of a molecule down its concentration gradient facilitated by specific carrier proteins
facilitated diffusion
112
movement of molecules across a membrane against a concentration gradient which is possible by the expenditure of energy
active transport
113
Two (2) types of channels that are mainly used in active transport
1. Sodium-Potassium Pump
2. Proton Pump
114
Where is the sodium-potassium pump used?
Nervous system (neurons and muscle cells)
115
Where is the proton pump used?
- photosynthesis
- respiration
(mitochondria)
116
uses the energy of one ATP molecule to pump 3Na+ outward and 2K+ into the cell
Sodium-potassium pump
117
expends metabolic energy to pump protons across membranes
proton pump
118
process of diffusion of ions (usually H+ ions AKA protons) across a selectively permeable membrane
chemiosmosis
119
Programmed cell death
Apoptosis
