Unit 2 Exam Flashcards
(123 cards)
1
Q
Cell theory
A
- All organisms are composed of 1 or more cells
- Cells are the smallest unit of life
- New cells arise only by division of pre existing cells
2
Q
Nuclear envelope
A
Protective phospholipid bilayer with pores allowing certain molecules to exit/enter
3
Q
Cytoskeleton
A
Supports organelles and cell shape and plays a role in cell motion; microtubule, intermediate filament, actin filament
4
Q
Microtubule
A
Tube of protein molecules
5
Q
Intermediate filament
A
Intertwined Protein fibers that provide support and strength
6
Q
Actin filament
A
Twisted protein fibers that are responsible for cell movement
7
Q
Centriole
A
Complex assembly of microtubules that occurs in pairs
8
Q
Cytoplasm
A
Semifluid matrix that contains the nucleus and other organelles
9
Q
dehydration reaction
A
removal of OH- and H+ to form a covalent bond between monomers
10
Q
hydrolysis reaction
A
hydrogen atom is attached to one subunit and and a hydroxyl group to the other, breaking a specific covalent bond in a macromolecule
11
Q
isomers
A
organic molecules with the same molecular or empirical formula but different arrangement of atoms
12
Q
structural isomers
A
differ in the actual carbon skeleton; ex. glucose and fructose
13
Q
stereoisomers
A
differ in the spatial arrangement of groups attached to carbon skeleton; ex. glucose and galactose
14
Q
chiral molecules
A
when 4 groups attached to carbon atom are different
15
Q
enantiomers
A
mirror image isomers
16
Q
polymers
A
constructed by joining together many small similar chemical subunits called monomers (carbohydrates, protein, and nucleic acids)
17
Q
hydroxyl group
A
on all 4 macromolecules
18
Q
carboxyl group
A
proteins and lipids
19
Q
amino group
A
proteins and nucleic acids
20
Q
methyl group
A
proteins and nucleic acids
21
Q
functions of proteins (7)
A
enzymes (catalysts), structural support, defense (snake venom), transport (hormones like insulin), movement, regulation, and storage
22
Q
nucleic acids
A
DNA/RNA, polymers of smaller molecules called nucleotides, made of sugar, nitrogenous base, and phosphate group
23
Q
nucleotides in DNA
A
adenine (A), thymine (T), guanine (G), and cytosine (C)
24
Q
base pairing in DNA
A
A pairs with T
G pairs with C
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nucleotides in RNA
adenine (A), guanine (G), cytosine (C), and uracil (U)
26
base pairing in RNA
A pairs with U
G pairs with C
27
DNA vs RNA reactivity
DNA has deoxyribose sugar, has one less oxygen containing hydroxyl group, making it more stable than RNA, which has ribose sugar
28
DNA function
encodes genetic information and keeps it safe for reproduction
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RNA function
reads the DNA code and uses it to build proteins, then moves it to ribosomal protein factories
30
bonds holding nucleic acids together
phosphodiester bonds
31
saturated
holds the max number of hydrogens per carbon
32
unsaturated
contains carbon-carbon double bonds, preventing them from binding to the max number of hydrogens
33
nucleolus
dense body of RNA and protein within nucleus, makes ribosomes
34
chromatin
consists of loosely coiled fibers of DNA and protein, condenses to form chromosome
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ribosomes
located in prokaryotic and eukaryotic cells, made up of protein and RNA
36
monosaccharides
simple 6 carbon sugar molecules; glucose, fructose, and galactose
37
disaccharides
2 monosaccharides bonded together; lactose (glucose and galactose), maltose (glucose and glucose), sucrose (glucose and fructose)
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polysaccharides
multiple monosaccharides
39
glycogen
polysaccharide made of glucose units, used for energy storage in animals
40
starch
polysaccharide used for energy storage in plants
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cellulose
polysaccharide used in plants for structural support
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amino acid
monomer of protein, contain an amino group and an acidic carboxylic acid group
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peptide bond
covalent bond that links 2 amino acids together
44
primary structure of a protein
amino acid sequence
45
secondary structure of a protein
hydrogen bonding patterns
46
tertiary structure of a protein
final folding into shape of a globular protein
47
quaternary structure of a protein
arrangement of subunits, when 2 or more polypeptide chains associate to form a protein
48
triglyceride
one glycerol molecule attached to 3 fatty acids
49
glycerol
each carbon bears a hydroxyl group, forms the backbone of a lipid molecule
50
phospholipid
glycerol, fatty acids, and a phosphate group
51
endoplasmic reticulum
network of interconnected membranes
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rough ER
synthesizes proteins, rough with ribosomes
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smooth ER
synthesizes lipids and hormones, contain significantly less ribosomes, contain many embedded enzymes
54
golgi apparatus
"packaging," (post office for the cell), receives proteins from rough ER to pack up and ship out, consists of flattened sacs connected to ER, uses transport vesicle made up of phospholipids
55
lysosomes
"cleanup crew," tiny membrane sacs containing enzymes to break down carbohydrates, proteins, and nucleic acids, absorbs problems to break it down safely
56
peroxisome
type of microbody with several oxidase enzymes that attack organic substances and degrade toxins, hydrogen peroxide is a byproduct and toxic to cells, so it pumps out catalase, an enzyme to clean it up
57
mitochondria
elongated fluid-filled sacs free in cytosol, produce key enzymes for metabolism and produces large amounts of ATP
58
microbody
enzyme-bearing vesicles in eukaryotic cells
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proteasomes
large, cylindrical complexes that cells use to recycle their proteins
60
vacuoles
specialized membrane bound structures in plant cells
61
cristae
inner, folded membrane in mitochondria
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chloroplasts
use light to generate ATP in plant cells
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endosymbiosis
proposes that some of today's eukaryotic organelles evolved as a consequence of symbiosis arising between two cells that were originally thought to be free living; ex. mitochondria might have originated as bacteria
64
chlorophyll
photopigment, makes plants green, can absorb light energy
65
nucleoid
in prokaryotes that hold DNA, not within a membrane
66
ribosomes
large, macromolecular machines composed of RNA and proteins, that synthesize all cellular proteins
67
ribosomal RNA
combination of RNA
68
messenger RNA
mRNA, carries coding information from DNA
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transfer RNA
tRNA, carries amino acids
70
endocytosis
moves material in cell
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phagocytosis
cell taking in solid particles of food
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pinocytosis
cell taking in fluids
73
exocytosis
exporting material out of cell, likely through secretory vesicle
74
cytoskeleton
dynamic system that support the shape of the cell and anchor organelle to specific locations; actin filament, intermediate filament, and microtubules
75
actin filament
microfilaments, made up of globular protein actin, tiny rods arranged in meshwork or bundles that aid in cellular movement
76
microtubules
largest, long slender tubes that form a cellular skeleton to help maintain cell shape, made up of alpha and beta tubulin
77
intermediate filament
most durable and versatile, tough fibrous, provide more structural stability; ex. keratin
78
centrosome
nonmembranous structure near the golgi apparatus, houses centrioles, microtubules organizing center
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centrioles
barrel shaped organelles that are important for cell division
80
motility
ability of a cell to move
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taxis
directed movement, movement with a purpose
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flagella
rod like extensions of a cell used for movement
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flagella in prokaryotic cells
rotate on proton pump, accelerating the cell forward, made up of microtubules, small and narrower
84
flagella in eukaryotic cells
use ATP to move, run in a bending movement, consists of tubulin proteins, large and thick
85
cilia
many hair like extensions used to move the cell or items over the cell; ex. food in trachea is moved out by cilia
86
cell wall in bacteria
peptidoglycan
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cell wall in plants
made of cellulose
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glycolipids
lipids with carbohydrate heads
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collagen fibers
made of collagen fibers with higher tensile strength
90
elastin fibers
generally lower tensile strength but higher elasticity
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fibronectin
glycoprotein, shorter fibers that connect to other fibers
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extracellular matrix in animal cells
collagen fibers, elastin fibers, and fibronectin fibers
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MHC proteins
self from non self recognition
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glycoprotein
protein with carbohydrate attached to polypeptide
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adherin junctions
use the protein cadherin (glycoprotein) to link cells by "zippering," link cells together and connect to actin filament, underneath septate/tight junctions
96
desmosomes
unique to vertebrates, cadherin based junction, usually circular or spot like
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septate junctions
found in invertebrates, ladder like structure of protein to seal off a sheet of cells or block passage of material between cells
98
gap junctions
in animal cells, specialized protein channels that directly connect the cytoplasm of neighboring cells; cell to cell communication; typically the bottom junction
99
plasmodesmata
cytoplasmic bridges that connect plant cells, allowing molecules to travel between them, through cell walls
100
tight junctions
found in vertebrates, belt-like attachment around cells, creating a permeability barrier, separating tissue spaces and regulating movement
101
4 components of cell membranes
phospholipid bilayer, integral membrane proteins, peripheral membrane proteins, cell-surface markers
102
functions of plasma membrane proteins
transporters, enzymes, cell-surface receptors, cell surface identity markers, cell to cell adhesion, cytoskeleton anchor
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transmembrane domain
integral membrane proteins reach from inside to outside of cell, alpha helixes
104
pore protein
transmembrane protein porin creates large open tunnels (pores) in a membrane with beta-pleated sheets
105
diffusion
net movement of substances from areas of high concentration to low concentration; ex. oxygen and steroid molecules are nonpolar so they easily pass through the membrane if concentration gradient permits
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simple diffusion
diffusion that requires no energy, based on unequal concentrations, substances can pass between the phopholipids
107
facilitated diffusion
passive diffusion, requiring no energy, but done through specialized membrane channels, required for polar molecules
108
ion channels
hydrophilic interior that provides an aqueous channel for ions to pass through when open
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carrier proteins
bind specifically to the molecule they assist to go in/out of cell
110
hypertonic solution
solution with higher concentration, water moves out of cell, cell shrivels up
111
hypotonic solution
solution with lower concentration, water moves into cell, cell swells
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isotonic solution
when 2 solutions have the same osmotic concentration
113
aquaporins
specialized protein channels for water
114
osmotic pressure
force needed to stop osmotic flow
115
hydrostatic pressure
pressure of the cytoplasm pushing out against the cell membrane
116
active transport
uses energy to power the movement of materials across a membrane against a concentration gradient
117
uniporters
transport a single type of molecule
118
symporters
transport 2 molecules in the same direction
119
antiporters
transport 2 molecules in the different directions
120
sodium potassium pump
active transport by antiporters to pump sodium into a cell and potassium out of a cell
1. ATP and 3 Na+ ions bind to pump
2. bound ATP is used to phosphorylate the pump
3. Na+ loses affinity to pump and diffuses away
4. 2 K+ ions are attracted to it and enters pump
5. dephosphorylation of protein, pushes K+ ions away
6. ATP binds again
121
coupled transport
transporting 2 substances across membrane; ex. membrane protein transports Na+ and glucose tags along by using the potential energy created by the sodium potassium pump
122
receptor-mediated endocytosis
cells have pits coated with protein clathrin that initiate when target molecules bind to receptor proteins
123
counter transport
active transport, where movement of a molecule across a membrane is matched by the movement of a different molecule in the opposite direction; ex. using potential energy of Na+ transport in sodium potassium pump to transport Ca+ ions in opposite direction
