Glossary of Biology Test #2

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What is the simplest collection of matter that can live?
-pass visible light through a specimen
-magnify cellular structures with lenses
Light Microscopes
What is the measurement used in microscopy?
-focus a beam of electrons through a specimen or onto its surcace
electron microscopes
provides for detailed study of the surface of a specimen
scanning electron microscope
provides for detailed study of the internal ultrastructure of cells
transmission electron microscope
takes cells apart & separates the major organelles from one another
cell fractionation
used to fractionate cells into their component parts
the centrifuge
when do cell parts separate?
less dense cell parts will separate from more dense cell parts
have internal membranes that compartmentalize their functions
eukaryotic cells
several basic features that all cells have in common
-pasma membrane
-cytosol (a semifluid substance)
-chromosomes & ribosomoes
site of protein synthesis
-do not contain a true nucleus
-no nuclear envelope
-dna located in nucleoid
-have a cell wall
prokaryotic cells
-membranous nuclear envelope
-generally quite a bit bigger
-have organelles surrounded by membranes
eukaryotic cells
have a higher surface to volume ratio which facilitates the exchange of materials into and out of the cell.
smaller cells
-functions as a selective barrier
-allows sufficient passage of nutrients & waste
plasma membrane
-phospholipid bilayer
major components of the plasma membrane
-cell walls
-central vacuole
things that plants have
eukaryotic cell's genetic instructions are housed in the
genetic instructions for which type of cell are housed in the nucleus?
eukaryotic cells
the nucleus contains most of the genes in which type of cell?
what contains most of the genes in the eukaryotic cell?
a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA
encloses the nucleus, separating its contents fromt the cytoplasm
nuclear envelope
particles made of ribosomal RNA and protein
build proteins in 2 cytoplasmic locates
2 cytoplasmic locates in which ribosomes build proteins
-free ribosomes
-bound ribosomes
found floating freely in the cytosol
free ribosomes
found attached to the rough endoplasmic reticulum
bound ribosomes
-free ribosomes
-bound ribosomes
proteins synthesize on
remain in the cell
free ribosomes
destined to exit the cell
bound ribosomes
various structures in the endomembrane system are related through
-direct physical continuity
-transfer of membrane segments known as vesicles
a sac made of membrane insidee of a cell
the endomembrane system includes
the endoplasmic reticulum
accounts for more than 1/2 the total membrane in many eukaryotic cells
endoplasmic reticulum
continuous with the nuclear envelope
the endoplasmic reticulum membrane (er)
2 distinct regions of er
-rough er
-smooth er
-contains ribosomes
-produces proteins & membranes (which are distributed by transport vesicles)
rough er
lacks ribosomes
smooth er
-synthesizes lipids
-metabolizes carbohydrates
-detoxifies poison
functions of smooth er
broken down in the cells of the liver
shipping & receiving center
golgi apparatus
consists of flattened memranous sacs called cisternae
golgi apparatus
side facing the nucleus
"cis" side
side facing the plasma membrane
"trans" side
receives many of the transport vesicles provided in the rough er
golgi apparatus
-modification of the products of the rough er
-manufacture of certain macromolecules
functions of the golgi apparatus
-moves from er to golgi
-coalesces with "cis" side of golgi
-always go to the cis side
-moves from the cis to the trans side
-membranes coalesce each time
-forms & exits golgi
-fuses wtih plasma membrane
vesicle proteins within the endomembrane system
3 methods of moving substances in or out of the cell
exocytosis & endocytosis
materials move out of the cell
a membranous sac of hydrolytic enzymes that can digest all kinds of macromolecules
-carry out intracellular digestion
3 processes of lysosome
involves phagocytosis & lysosomes fuse with food vacuole.
intracellular digestion
paramecium: unicellular organism that:
carries out intracellular digestion
the cellular uptake of macromolecules & particulate substances by localized regions of the plasma membrane that surround the substance
a type of endocytosis involving large particulate substances
macromolecules or substances form vacuoles once inside the cell
cytoplasmic extension used for feeding in some cells
food vacuoles are formed by
lysosomes break down damaged organelles within a cell recycles organic molecules
the changes that occur within a cell as it undergoes progammed cell death
genetically programmed to break open at a specific time
are formed by phagocytosis
food vacuoles
pump excess water out of protist cells
contractile vacuolles
found in plant cells & hold reserves of importnt organic compounds and water
central vacuoles
a complex & dynamic player in the cell's compartmental organization
the endomembrane system
types of vacuoles
change energy from 1 form to anotehr
mitochondria & chloroplasts
-sites of cellular respiration
glucose molecule is broken down to release energy
found in almost all plant & animal cells
smootther outer & inner folded into cristae
mitochondria has 2 membranes
capture of light energy
-contail chlorophyll
-site of photsynthesis
process in which light energy is converted to the chemical energy in lucose
found in leaves & other green organs of plants & in algae
parts of chloroplast structure
membranous sacs
internal fluid
a network of fibers extneding throughout the cytoplasm
the cytoskeleton
support motility & regulation
roles of the cytoskeleton
gives mechanical support to the cell
involved in cell motility which utilizes motion proteins
hollow tubes
shape the cell
guide movement of organelles
help separate the chromosome copies in dividin cells
contain specialized arrangements of microtubules
cilia & flagella
locomotor appendages of some cells
cilia & flagella
beating pattern
back & forth motion
ciliary motion
flagella & ciliary motion
share a common ultrastructure "9+2" arrangement of microtubules
cilia & flagella
9 pairs make a circle & 2 singles are in the middle
9+2 arrangement of microtubules
built from molecules of the protein actin
involved in amoeboid movement & involves the contraction of actin & myosin filaments
another form of locomotion by microfilaments
cytoplasmic streaming
exhibits selective permeability & allows some substances to cross it more easily than others
plasma membrane
states that a membrane is a fluid structure with a "mosaic" of various proteins embedded in it
fluid mosaic model of membrane structure
can move iwthin the bilayer
flip flop 1 time per month
lateral movement
can drift within the bilayer
-unsaturated hydrocarbon tails (with kinks)
-saturated hydrocarbon tails (more fluid)
phospholipids may have
unsaturated hydrocarbon tails
with kinks
saturated hydrocarbon tails
more fluid
affects the fluidity of the plasma membrane
the type of hydrocarbon tails in phospholipids
weged between phospholipid molecules in the plasma memrane of animals
molecule with 4 interlockig rings (make the membrane less fluid)
a collage of diferent proteins embedded in the fluid matrix of the lipid bilayer
membrane proteins
penetrate the hydrophobic core of the lipid bilayer
integral proteins
appendages loosely bound to the surface of the membrane
peripheral proteins
provide a method of moving a particular solute from one side of the plasma membrane to another
transport proteins
types of transport proteins
may provide a hydrophillic channel across the mebrane that is selective for a particular solute
channel proteins
move a solute across when the protein changes shape
carrier proteins
a cell's ability to distinguish one type of neighboring cell from another
cell-cell recognition
-sorting of cells into tissues and organs in an animal embryo
-rejection of foreign cells by the immunesystem
importance of cell-cell recognition
interaction with the surface molecules of other cells
cell-cell recognition
interact with the surface molecule of other cells, facilitating cell-cell recognition
glycoproteins & glycolipids
a cell must exchange materials with its surroundings
a process controlled by the plasma membrane.
lipid soluble and can pass through the membrane rapidly
hyrdrophobic molecules
do not cross the membrane rapidly
polar molecules
allow passage of hydrophic substance across the membrane
transport proteins
molecules move due to
thermal energy
diffusion of a substance across a mebrane with no energy investment
passive transport
the tendency for molecules of any substance to spread out evenly into the available space
there's net diffusion (one side gaining) until
equilibrium (both sides equal) then there's transfer but no side has more than the other at any given time
net diffusion
one side gains
the movement of substances from an area of higher concentration of that substance to an area of lower concentration
substances diffuse
down their concentration gradient
the difference in concentration of a substance from 1 area to another
concentration gradient
membane is permeable to
water not solutes
water moves from an area of higher concentration of water to an area of lower concentration of water
water molecules move from an are of
lower solute concentration to an area of higher solute concentration (this is backwards in diffusion)
the ability of a solution to cause a cell to gain or lose water
-has a reat impact on cells without walls
ideally the molarity
of the solution outside the cell & inside the cell is the same
if a solution is isotonic
the concentration of solutes outside the cell is the same as it is inside the cell
in comparing 2 solutions referrin to the one with a greater solute concentration
if the solution outside the cell is hypertonic then
the cell will lose water
in comparing 2 solutios- referring to the one with a lower solute concentration
if the solution outside the cell is hypotonic to the cell
the cell will gain water
an animal cell (hypotonic solution)
lysed (water goes in)
water comes in & out
isotonic (normal)
water comes out
shriveled (hypertonic)
organisms without rigid cell walls living in hypertonic or hypotonic environments
must have special adaptations for osmoregulation (has to e able to regulate water flow)
how organisms regulate solute concentrations & balance the gain & loss of water
name the osmoregulatory device in paramecium
contractile vacuole
help maintain water balance
cell walls
if a plant cell is turgid
it is in a hypotonic envionment it is very firm a healthy state in most plants
if a plant cell is flaccid (limp)
it is in an isotonic environment
if a plant cell is in a hypertonic solution
the cell will lose water to its surroundings & shrink
water will diffuse
out of the cytosol & large central auole
as the plant cell contents shrviels
its plasma membrane pulls away from the wall
when the plasma membrane pulls away from the wall
if something wilts
plasmolysis has occurred
water comes in when
turgid (normal
water coes in & out when
water comes out when
can predict the direction in which water will flow
water potential
water potential is governed by
solute concentration & applied pressure
has to do with cell wall
applied pressure
gives scientists a numberical value
water potential
pure water has the water potential & molarity
adding solutes
lowers the water potential
if the water potential of pure water is zero adding solutes
makes the water potential negative
water moves
from an area of high water potential to an area of lower water potential
diffusion/osmois & facilitated diffusion
2 types of passive transport
facilitated diffusion
no energy & with a concentration gradient
to help-move faster
speed the movement of molecules across the plasma membrane
transport proteins
specific for the solute & specific binding sites
transport proteins
provide corridors that allow a specific molecule or ion to cross the membrane
channel proteins
undergo a subtle change in shape that translocates the solute binding site across the mebrane
carrier proteins
uses energy to move solutes against their gradients
active transport
if you go up a tree
it takes action (kinetic energy)
if you're on limb & step off
it's passive (doesn't take any energy)
enables a cell to maintain internal concentrations of small molecules that differ from concentrations in its environment
active transport
if it requires energy it's in the form of
an area of lower concentration to an area of higher concentration
carrier proteins
a certain concentration of sodium & potassium ions
all cells must maintain
a higher concentration outside the plasma membrane
a higher concentration inside the plasma membrane than outside
for every 3 pumped out of the cell there has to be 2 pumped into the cell
for every 3 cytoplasmic sodium pumped out of the cell there has to be 2 extracellular potassium ions pumped into the cell
one type of active transport system
sodium potassium pump
higher to lower
passive transport
if something goes across the bilayer from higher to lower
transport & carrier proteins
facilitate diffusion
lower to higher concentration
active transport
more of 1 type of chemical on one side than on another
chemical gradient
the voltage difference across a membrane
membrane potential
the inside of the cell
is negative compared to the outside
two forces drive
the diffusion of ions across a membrane
caused by the concentration electrical gradient of ions across a membrane
electrochemical gradient
examples of elctrochemical gradient mechanisms
-sodium-potassium pump
-prton pump
pumps protons or hydrogen ions
proton pump
2 examples of electrochemical gradient mechanisms
both are examples of active transport
bulk transport across the plasma membrane occurs by
exocytosis & endocytosis
transport vesicles migrate to teh plasma membrane, fuse with it, & release their contents.
the cell takes in macromolecules by formng new vesicles from the plasma membrane
phagocytosis, pinocytosis, receptor
3 types of endocytosis
large macromolecules are taken in
cell drinking (particles of fluid are taken in)
cell mediated
receptors on outside
receptor endocytosis
80% genetics
the totality of an organisms chemical reactions
the transformation of one type of matter to another type of matter
law of thermodynamics
the transformation of oe type of energy to another type of energy
laws of thermodynamics
has many steps that are each catalyzed by a specific enzyme
metabolic pathway

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