Flashcards in chapter 3 Deck (96)
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1
cell theory
cell is basic structural and function unit of life
2
plasma membrane
separates intracellular fluids from extracellular fluids
3
glycocalyx
glycoprotein area abutting the cell that provides highly specific biological markers which cells recognize one another
4
fluid mosaic model
double bilayer of lipids with imbedded, dispersed proteins
- bilayer consists of phospholipids, cholesterol, and glycolipids
5
glycolipids
are lipids with attached sugar groups
6
fluid mosaic model
slide 6
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integral proteins
attached with hydrophobic and hydrophilic regions (transmembrane proteins and used for transporting)
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peripheral proteins
attached loosely integral proteins that are network of filaments that help support the membrane from the cytoplasmic side
9
transport membrane porteins
provides a hydrophilic channel across membrane that is selective for a particular solute. some hydrolyze ATP as an energy source to pump
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enzymatic activity membrane protein
active site exposed to substances in the adjacent solution. in some cases, several catalyze sequential steps of a metabolic pathway
11
receptors for signal transduction membrane protein
have a binding site with specific shape for specific thing to bing on. chemical change can occur
12
intercellular joining membrane proteins
membrane proteins of adjacent cells may be hooked together in various kinds of intercellular junctions. they provide temporary binding sites that guide cell migration and other cell to cell interactions
13
cell to cell recognition membrane proteins
some glycoproteins serve as identification tags that are specifically recognized by other cells
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glycoproteins
proteins bonded to short chains of sugars
15
attachment to cytoskeleton and extracellular matrix membrane protein
elements of cytoskeleton and extracellular matrix are anchored. fix locations and cell movement
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lipid rafts
conc. platforms for cell signaling molecules
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3 factors that bind cells together
glycoproteins in the glycocalyx act as an adhesive. wavy contours of the membranes of adjacent cells fit together. special cell juctions
18
tight junction
impermeable junction that encircles the cell. ( epithelial cells lining GI tract)
19
desmosome
anchoring junction scattered along the sides of cells (skin and heart muscle)
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gap junction
nexus that allows chemical substances to pass between cells (heart and smooth muscle)
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diffusion
molecules/ ions move from high to low conc.
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simple diffusion
diffusion of molecule or ion will directly through a plasma membrane (lipid soluble and small enough to pass through membrane channels and assisted by a carrier molecule)
23
facilitated diffusion
assisted diffusion where the substance binds to a carrier protein or passes through a channel (uses kinetic energy) transports glucose, amino acids and ions
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osmosis
diffusion of water solvent across a semipermeable membrane
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tonicity
how a solution affects cell volume
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isotonic
solutions with the same solute conc. that of the cytosol
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hypertonic
solutions having greater solute conc. than that of the cytosol
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hypotonic
solutions having lesser solute conc. than that of the cytosol
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active transport
uses ATP to move solutes across a membrane using a carrier protein
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primary ative transport
energy to do work comes from hydrolysis of ATP. moves against conc. gradient
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secondary transport
use of an exchange pump (Na+ and K+ pumps) indirectly to drive the transport of other solutes
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symport system
2 substances moved in same direction
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antiport system
2 substances are moved across a membrane in opposite directions
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vesicular transport
transport of large particles and macromolecules across plasma membrane
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exocytosis
moves substances from cell interior to extracellular space
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endocytosis
enables large particles and macromolecules to enter the cell
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transcytosis
moving substances into, across, then out of cell
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vesicular trafficking
moving substances from one area of cell to another. plasma membrane infolds and bringing extracellular fluid and solutes into the interior of the cell
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phagocytosis
pseudopods engulf solids and bring them into cell's interior
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receptor mediated endocytosis
clathrin coated pits provide the main route for endocytosis and transcytosis
41
non clathrin coated vesicles
caveolae that are platforms for a variety of signaling molecules
42
membrane potential
selective permeability across a membrane leads to a membrane potential (voltage across a membrane)
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resting potential
-50- -100 mV. polarized. maintained by active transport
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how does a cell interact w/ its environment
direct contact & extracellular chemicals, hormones and neurotransmitters
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contact signaling
cell to cell contact
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electrical signaling
respond to changes in a membrane potential
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chemical signaling
ligands(neurotransmitters, hormones, paracrine) bind to plasma membrane receptors
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cytoplasm
material b/w plasma membrane and the nucleus
49
cytosol
largely water w/ dissolved protein, sals, sugars, and other solutes
50
organelles
metabolic machinery of the cell
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membranous
mitochondria, peroxisomes, lysosomes, endoplasmic reticulum, golgi apparatus
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nonmembranous
cytoskeleton, centriols, and ribosomes
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inclusions
chemical substances(glycosomes, glycogen granules, pigment
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mitochondria
double membrane structure w/ shelf- like cristae. privte most of cell's ATP through aerobic respiration
55
ribosomes
contain protein and rRNA, protein synthesis
56
endoplasmic reticulum (ER)
interconnected tubes and parallel membranes enclosing cisternae that is conninuous with the nuclear membrane
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rough ER
external surface stuffed with ribosomes
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smooth ER
tubules arranged in a looping network
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golgi apparatus
stacked and flattened membranous sacs, fn in modification, conc. and packaging of proteins
60
lysosomes
spherical membranous bags containing digestive enzymes (found in luekocytes, immune cells, and melanocytes
61
endomembrane system
includes:
nuclear envelope, smooth and rough ER, lysosomes, vacuoles, transport vesicles, golgi apparatus, plasma membrane
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peroxisomes
membranous sacs containing oxidases and catalases. detoxify harmful or toxic substances
63
cytoskeleton
series of rods running through the cytosol. consists of microtubules, microfilaments, and intermediate filaments
64
microtubules
hollow tubes made of tubulin, determine shape of cell
65
microfilaments
strands of actin attached to cytoplasmic side of plasma membrane, strengthens cell surface
66
intermediate fibers
tough insoluble protein fibers with high tensile strength
67
microtubules and microfilaments
both powered by ATP
68
centrioles
small barrel shaped organelles located in the centresome near nucleus. organize mitotic spindle during mitosis. form bases of cilia and flagella
69
cilia
move substances in one direction across cell surface
70
nucleus
gene containing control centrer. dictates the kinds and amounts of proteins to be synthesized
71
nuclear envelope
permeable double membrane barrier containing pores
72
nucleoplasm
enclosed jelly like substance containing essential solutes
73
nucleoli
dark staining spherical bodies within the nucleus where ribosome production occurs
74
chromatin
distinct compartments in rich specific protein sets. threadlike strands of DNA and histones. arranged in nucleosomes. from chromosomes
75
cell cycle
interphase, mitotic phase, cytokinesis
76
G1
metabolic activity and vigorous growth
77
G0
no activity cells that permanetly cease dividing
78
S
DNA replication
79
G2
preparation of enzymes and proteins for division
80
cytokinesis
division of cytoplasm
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control of cell division
surface to volume ratio of cells, chem signals(growth factors and hormomes), when cells touch, cyclins and Cdk complexes
82
mRNA
carries genetic info from DNA in the nucleus to the ribosomes in the cytoplasm
83
tRNA
bound to amino acid base pair w/ codons of mRNA at the ribosome to begin process of protein synthesis
84
rRNA
structural component of ribosomes
85
RNA polymerase
an enzyme that oversees the synthesis of RNA
86
transcription initiation
unwinds the DNA template
87
transcription elongation
adds complementary ribonucleoside triphosphates on the DNA template and joins these RNA nucleotides together
88
transcription termination
encodes a termination signal to stop transcription
89
translation initiation
ribosomal subunit binds to a special methionine
90
translation elongation
mRNA is moved through the ribosome in one direction adding one amino acid at the time
91
translation termination
stop codon causes the stop
92
start codon
AUG
93
stop codon
UAA, UAG, UGA
94
Antisense RNA
prevents protein coding RNA from being translated
95
microRNA
small RNAs that interfere with mRNA made by certain exons
96
