Bio test 2
what should a properly working membrane be as fluid as
olive oil
What is the endomembrane system?
regulates protein traffic and performs metabolic functions in the cell
purpose of microfilaments
resist tension
what is the evidence of endosymbiont theroy
1. chloroplast, mitochondria has double membranes 2. they have there own DNA 3. contain ribosomes 4. semi-autonomous
how many membranes does the nuclear envelope have
2
FORM A STABLE BOUNDARY BETWEEN TWO AQUEOUS REGIONS
AMPHIPATHIC PHOSPHOLIPIDS
ligand
Any molecule that bonds specifically to a receptor site of another molecule.
cell junctions
Communication between cells; binding of cells in tissues
what are desmosomes
Complexes of membrane proteins, anchoring proteins (plaque) and intermediate filaments
DESMOSOMES (anchoring junctions)
Fasten cells together into strong sheets
_____ aid in the coordination of the activities of adjacent animal cells. Gap (communicating) junctions Tight junctions Keratin fibers Plasmodesmata Desmosomes
Gap (communicating) junctions
what is tight junction
Membranes of neighboring cells joined via membrane protein complexes
For a protein to be an integral membrane protein, it would have to be _____. amphipathic, with at least one hydrophobic region hydrophobic hydrophilic exposed on only one surface of the membrane
amphipathic, with at least one hydrophobic region
GAP JUNCTIONS (communicating junctions)
Provide cytoplasmic channels between adjacent cells, Allow for flow of ions and small molecules between cells
binding of ligands to receptors triggers vesicle formation
Receptor-mediated endocytosis
What performs active transport?
SPECIFIC PROTEINS EMBEDDED IN MEMBRANES
how does cotransport work
TRANSPORT OF ONE SOLUTE INDIRECTLY DRIVES TRANSPORT OF OTHER SUBSTANCES
What will happen to a red blood cell (RBC), which has an internal ion content of about 0.9%, if it is placed into a beaker of pure water? The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC. The cell would shrink because the water in the beaker is hypertonic relative to the cytoplasm of the RBC. The cell would shrink because the water in the beaker is hypotonic relative to the cytoplasm of the RBC. The cell will remain the same size because the solution outside the cell is isotonic.
The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC.
COUPLED TRANSPORT BY MEMBRANE PROTEIN
cotransport
what is the purpose of a selective permeable structure
allow regulation of cells traffic
TRANSPORT AIDED BY PROTEINS
facilitated diffusion
Cell membranes have distinct inside and outside faces. Which of the following statements is the most likely explanation for the membrane's asymmetrical nature? The two sides of a cell membrane face different environments and carry out different functions. Since cell membranes communicate signals from one organism to another, the cell membranes must be asymmetrical. Proteins only function on the cytoplasmic side of the cell membrane, which results in the membrane's asymmetrical nature. Since the cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium, the membrane must be asymmetrical.
The two sides of a cell membrane face different environments and carry out different functions.
What is the function of the nuclear pore complex found in eukaryotes? a. It regulates the movement of proteins and RNAs into and out of the nucleus. b. It synthesizes the proteins required to copy DNA and make mRNA. c. It assembles ribosomes from raw materials that are synthesized in the nucleus. d. It synthesizes secreted proteins.
a
Which organelle plays a role in intracellular digestion? a. lysosome b. plasmodesma c. Golgi apparatus d. chloroplast e. ribosome
a
The force driving simple diffusion is ________, while the energy source for active transport is ________. a concentration gradient; ATP hydrolysis phosphorylated carrier proteins; ATP transmembrane pumps; an electrochemical gradient a concentration gradient; ADP
a concentration gradient; ATP hydrolysis
what is the cytoskeleton
a network of fibers extending throughout the cytoplasm
microfilaments are also known as
actin
USES ENERGY TO MOVE A SOLUTE AGAINST ITS CONCENTRATION GRADIENT
active transport
Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells? The animal cell is in _____. a hypertonic solution, and the plant cell is in an isotonic solution an isotonic solution, and the plant cell is in a hypotonic solution a hypotonic solution, and the plant cell is in an isotonic solution an isotonic solution, and the plant cell is in a hypertonic solution
an isotonic solution, and the plant cell is in a hypotonic solution
CHANNEL PROTEINS FOR WATER MOLECULES
aquaporins
Which of the following molecules dramatically increases the rate of diffusion of water across cell membranes? the sodium-potassium pump ATP gated ion channels aquaporins
aquaporins
What do ribosomes do?
assemble proteins
ENERGY FOR ACTIVE TRANSPORT USUALLY IN FORM OF
atp
Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm. This observation suggests that this cell is actively producing large amounts of which of the following molecules? a. lipids b. proteins c. polysaccharides d. nucleic acids
b
Which of the following are found in plant, animal, and bacterial cells? a. mitochondria b. ribosomes c. chloroplasts d. endoplasmic reticulum
b
Which of the following is a major difference between prokaryotic cells and eukaryotic cells? a.Eukaryotic cells have flagella, while prokaryotic cells do not. b.Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not. c. Prokaryotic cells are generally larger than eukaryotic cells. d. Prokaryotic cells have cell walls, while eukaryotic cells do not.
b
Which of the following macromolecules leaves the nucleus of a eukaryotic cell through pores in the nuclear membrane? a. phospholipids b. mRNA c. DNA d. amino acids
b
Which structure is common to plant and animal cells? a. centriole b. mitochondrion c. central vacuole d. chloroplast
b
ser main role
biosynthesis of lipids and steroid hormones
function of rer
biosynthesis of proteins, modification of proteins
what is the er
biosynthetic factory
how do cells crawl along surface
by pseudopodia
where are vacuoles made
by the er and golgi
A cell with a predominance of rough endoplasmic reticulum is most likely ________. a. producing large quantities of proteins in the cytosol b. producing large quantities of carbohydrates for storage in the vacuole c. producing large quantities of proteins for secretion d. producing large quantities of carbohydrates to assemble an extensive cell wall matrix
c
A cell with a predominance of smooth endoplasmic reticulum is likely specialized to ________. a.import and export large quantities of protein b.actively secrete large quantities of protein c. synthesize large quantities of lipids d. store large quantities of water
c
In bacteria, DNA will be found in ________. a. a membrane-enclosed nucleus b. mitochondria c. the nucleoid d. ribosomes
c
The nuclear lamina is an array of intermediate filaments that line the inner side of the nuclear membrane. If a chemical treatment caused the lamina to disassemble, what would you expect to be the most likely immediate consequence? a. a loss of genetic information from chromosomes b. the inability of the nucleus to divide during cell division c. a change in the shape of the nucleus d. closing of nuclear pores
c
Which of the following correctly matches an organelle with its function? a. lysosome ... movement b. mitochondrion ... photosynthesis c. central vacuole ... storage d. nucleus ... cellular respiration e. ribosome ... manufacture of lipids
c
Which organelle often takes up much of the volume of a plant cell? a. chloroplast b. lysosome c. central vacuole d. Golgi apparatus
c
CHANGE SHAPE, TRANSLOCATING SOLUTE-BINDING SITE ACROSS MEMBRANE
carrier proteins
what does ecm regluate
cell behavior
extracellular compone of fungi
cell walls or chitin
An animal cell lacking carbohydrates on the external surface of its plasma membrane would likely be impaired in which function? attaching the plasma membrane to the cytoskeleton transporting ions against an electrochemical gradient establishing a diffusion barrier to charged molecules cell-cell recognition
cell-cell recognition
membrane carbohydrates
cell-cell recognition
Mitrochondria are the sites of
cellular respiration
what is the extracellular component of plants
cellulose or cell walls
Where is the MTOC located?
centrosome
PROVIDE CORRIDORS FOR SPECIFIC MOLECULES
channel proteins
what are the different types of facilitated diffusion
channel proteins, carrier proteins
plasmodesmata
channels through cell walls that connect the cytoplasms of adjacent cells
Which structure below is independent of the endomembrane system? plasma membrane Golgi apparatus nuclear envelope chloroplast
chloroplast
Thylakoids, DNA, and ribosomes are all components found in _____. lysosomes mitochondria chloroplasts nuclei
chloroplasts
at warm temps what retains movement o phospholipids
cholesterol
DNA + HISTONE
chromatin
each ____________ is a ________ _____ _________ associated with proteins
chromosome, single dan molecule
microtubules make up
cilia and flagella
what is cytoplasmic streaming
circular flow of cytoplasm within cells
the _________ organizes structures and activities in the cell
cytoskeleteon
vesicles can travel along tracks provided by
cytoskeleton
what is common to prokaryotes and eukaryotes
cytosol, plasma membrane, chromosomes, ribosomes
what are the 2 locations of ribosomes
cytosol, rough er
Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is _____. a. translation of a DNA nucleotide sequence into a sequence of amino acids b. removal of introns from RNA and the stitching together of exons c. translation of an RNA nucleotide sequence into a sequence of amino acids d. transferring of information from DNA to messenger RNA e. linking of nucleotides to form a polypeptide
d
Which of the following frequently imposes a limit on cell size? a. the absence of a nucleus b. the number of mitochondria in the cytoplasm c. the volume of the endomembrane system d. ratios of surface area to volume
d
Which statement correctly describes the nuclear envelope of a eukaryotic cell? a. The nuclear envelope is a single membrane, consisting of a phospholipid bilayer. b. Plasmadesmosomes in the nuclear envelope permit the exchange of macromolecules between the nucleus and the cytoplasm. c. All of the proteins of the cell are synthesized on ribosomes bound on the nuclear envelope. d. The nuclear envelope is continuous with the endoplasmic reticulum. e. The outer layer of the nuclear envelope is coated with laminin.
d
The primary role of _____ is to bind animal cells together. desmosomes plasmodesmata tight junctions gap (communicating) junctions the cytoskeleton
desmosomes
what does the ser in the liver do
detoxifaication
TENDENCY FOR MOLECULES TO SPREAD OUT EVENLY IN AVAILABLE SPACE
diffusion
what is asymmetrical distribution
distinct inside and outside faces
Chromosomes condense as cells prepare to
divide
SUBSTANCES DIFFUSE PASSIVELY
down concentration gradients
what drives the movement in cilia and flagella
dynein
what is the function of the nuclear envelope
encloses nucleus, separating from cytoplasm
TRANSPORT INTO CELL
endocytosis
what accounts for half the total membrane content
er
TRANSPORT OUT OF CELL
exocytosis
what are the types of bulk transport
exocytosis and endocytosis
how does pancreas cells relate insulin into bloodstream
exoytosis
extracellular compone in animals
extracellular matrix
cholorplast
found in plants and algae, are the sites of photosynthesis
OPEN & CLOSE IN RESPONSE TO STIMULUS
gated ion channels
What are chromosomes?
genetic blueprints
ECM composition
glycoproteins
PLANTS USE ______________________GENERATED BY _____________________ TO DRIVE ______________________ OF NUTRIENTS INTO CELL
gradient of H+ions, proton pumps, active transport
Amoebae move by crawling over a surface (cell crawling), which involves ________. growth of actin filaments to form bulges in the plasma membrane reinforcement of the pseudopod with intermediate filaments localized contractions driven by myosin and microtubules assembly of microtubule extensions that vesicles can follow in the direction of movement
growth of actin filaments to form bulges in the plasma membrane
what is the function of thylakoids
harvest energy for photosynthesis
at cool temps, cholesterol does what
hinders solidification by preventing tight packing
What can pass directly through the cell membrane?
hydrophobic molecules, small uncharged molecules
what are plants cells normal in
hypotonic
where are the components of lysosomes made
in the rer and processed in golgi
what is the purpose of the cristae of mitrocondria
increased surface area
penetrate the hydrophobic core
integral proteins
what lies between the inner and outer membranes of mitrocondria
inter-membrane space
ECM proteins bind to receptor proteins in the plasma membrane called
intergrins
which is the most permanent cytoskeleton
intermediate
what is the middle level sized cytoskeleton
intermediate filaments
stroma
internal fluid of chloroplast
FACILITATE DIFFUSION OF IONS
ion channels
Celery stalks that are immersed in fresh water for several hours become stiff. Similar stalks left in a 0.15 M salt solution become limp. From this we can deduce that the fresh water_____. and the salt solution are both hypertonic to the cells of the celery stalks is isotonic and the salt solution is hypertonic to the cells of the celery stalks is hypertonic and the salt solution is hypotonic to the cells of the celery stalks is hypotonic and the salt solution is hypertonic to the cells of the celery stalks
is hypotonic and the salt solution is hypertonic to the cells of the celery stalks
what are animal cells normal in
isotonic
what is the movements of phospholipids
lateral movement and flipflop
what are microtubules
long, hollow protein cylinders- polymers of Alpha and beta tubulin
water will travel from ______ to _____ until equal on both sides
low to high
A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in _____. lysosomes vacuoles secretory vesicles Golgi vesicles
lysosomes
ACTIVE TRANSPORT ALLOWS CELLS TO
maintain concentration gradients from different surrondings
determine most of the membrane's specific functions
membrane proteins
what is thylakoids
membranous sacs, continus and fooled into grana
microvilli of intestinal cells are
microfilaments
what is the smallest cytoskeleton
microfilaments
what part of the cytoskeleton can depolymerize and reform allowing cell to change shape and move
microfilaments
The cilia and flagella of eukaryotic cells are composed of _____. microfilaments intermediate filaments tonofilaments pili microtubules
microtubules
what is the thickest cytoskeleton
microtubules
Suppose a young boy is always tired and fatigued, suffering from a metabolic disease. Which of the following organelles is most likely malfunctioning in this disease? lysosomes mitochondria Golgi apparatus smooth endoplasmic reticulum
mitochondria
the space surrounded by inner membrane of mitrocondria is
mitochondria matrix
The cytoskeleton interacts with _____ to produce motility
motor proteins
A sodium-potassium pump ________. moves three potassium ions out of a cell and two sodium ions into a cell using energy from ATP hydrolysis moves three potassium ions out of a cell and two sodium ions into a cell while producing ATP for each cycle move three sodium ions out of a cell and two potassium ions into a cell and generates an ATP in each cycle moves three sodium ions out of a cell and two potassium ions into a cell using energy from ATP hydrolysis
moves three sodium ions out of a cell and two potassium ions into a cell using energy from ATP hydrolysis
how in eukaryotes do we increase the size of an organism
multicellularity
what is chromosomes in eukayrtoe cells like
multiple, linear in nucleus
what happens when actin and myosin slide past eachother
muscle contraction
Suppose a cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from ________. a plant, but not an animal nearly any eukaryotic organism an animal, but not a plant a bacterium, but not a eukaryote
nearly any eukaryotic organism
what is unique to prokaryotes
nuceoid, single circular chromosome, cytoplasm bound by plasma membrane
what is the inside of the nucleus envelope lined with
nuclear lamina
In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? on the outer surface of the nucleus on the outside of vesicles on the inside surface of the cell membrane on the inside surface of the vesicle
on the inside surface of the vesicle
DIFFUSION OF WATER ACROSS SELECTIVELY PERMEABLE MEMBRANE
osmosis
there is a ______ difference between cytosol, inter membrane space, and matrix
pH
facilitated diffusion is what type of transport
passive
DIFFUSION ACROSS MEMBRANE WITH NO ENERGY INVESTMENT
passive transport
are bound to membrane surface
peripheral proteins
An organism with a cell wall would most likely be unable to take in materials through _____. phagocytosis osmosis facilitated diffusion active transport
phagocytosis
White blood cells engulf bacteria using _____. osmosis phagocytosis receptor-mediated exocytosis pinocytosis
phagocytosis
cell engulfs a particle in a vacuole
phagocytosis
how are food vacuoles formed
phagocytosis
what are the 3 types of endocytosis
phagocytosis, pinocytosis, receptor-mediated endocytosis
molecules dissolved in droplets are taken up when extracellular fluid is "gulped" into tiny vesicles
pinocytosis
The difference between pinocytosis and receptor-mediated endocytosis is that _____. pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity. pinocytosis increases the surface area of the plasma membrane, whereas receptor-mediated endocytosis decreases the plasma membrane surface area. pinocytosis brings only water molecules into the cell, but receptor-mediated endocytosis brings in other molecules as well. pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot.
pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity.
what movement does flagellum move in
propellear
free ribosomes produces
proteins used within the cell
what is the nuclear lamina composed of
proteins, that maintain the shape of the nucleus
CREATE A PROTON GRADIENT ACROSS BIOLOGICAL MEMBRANES
proton pumps
what is the function of the goldi
receives, modifies, and repackages products to be sent out of around cell
cis- Golgi
receiving side
autophagy
recycling organelles and macromolecules
what is the function of nuclear pores
regulate entry and exit of molecules from nuclues
what microscope does 3d images
scanning electron microscope
what is plasma membrane
selective barrier
the cell membrane is
selectively permeable
what is cytosol
semifluid matrix
what is the function of microtubules
shape, movement of organelles, seperating chromosomes
trans- golgi
shipping side
what are chromosomes like in prokaryotic cells
single, circular in nucleic region
microtubule organizing center
site of nucleation and organization of microtubules
prokaryotes are much ________ compared to eukaryotes
smaller
what are the two membranes of mitrocondria
smooth outer membrane, inner membrane folded into cristae
what are microfilaments
solid rods made of twisted double chains of actin
nucleous
ster of rRNA synthesis
in muscle cells what does ser do
stores and release calcium as needed for muscle contraction
what is the purpose of intermediate filaments
support cell shape, fix organelles in place
roles of cytoskeleton
support, motility, regulation
what affect fluidity
temperature, nature of fatty acids
what is the endosymbiont theroy
that chloroplast and mitrocondriaa were originally there own thing
What is the fluid mosaic model?
the lipids and proteins of the cell membrane always flow and move around
at what end does growth occur
the positive ends
Membrane potential
the voltage difference across a membrane created by differences in distribution of positive and negative ions across a membrane
what are the two structures of choroplast
thylakoids, stroms
Which of these cell junctions form a barrier to the passage of materials? keratin fibers plasmodesmata tight junctions desmosomes (anchoring junctions) gap (communicating) junctions
tight junctions
water balance
tonicity
actin serves as a ______ for the movement of the motor protein, _______
track, myosin
span the membrane
transmembrane
ALLOW FOR PASSAGE OF HYDROPHILIC SUBSTANCES ACROSS MEMBRANE
transport proteins
bound ribosomes produce proteins
transported out of the cell
What happens in phagocytosis?
vacuole fuses with a lysosomes to digest the particle
what are lysosomes
vesicle containing hydrolytic enzymes
how are things sent to the golgia
via transport vesicles
How does bulk transport work?
via vesicles
what does plasmodesmata do
water and small solutes pass through
how is transmembrane protein orientation determined
when it is built by er and golgi
what movement does cilia move in
whiplike
where do some metabolic steps of cellular respiration occur
within the mitochondrial matrix
Does bulk transport require energy?
yes bulk transport requires energy