has a well defined nucleus bound by a nuclear membrane, with a variety of organelles located outside the nuclear membrane.
Animal cells, plant cells, and fungal cells are all __________ cells.
Prokaryotic cells are cells that...
lack well defined membrane-bound nuclei and a full complement or organelles
The principal features of eukaryotic cells are...
A cell wall (not in animal cells)
Cell walls are found on...
plant cells, yeast cells and bacteria
The cell wall is composed of...
All cells don't have a cell wall, but in terms of exterior surfaces, all cells have a ...
Cell membranes are composed primarily of...
protein and phospholipids
Peripheal proteins are...
proteins that are embedded in one of the two surfaces of the membrane (half in, half out)
Transmembrane proteins are...
proteins that penetrate completely through the membrane
membrane dynamics is termed ....
the fluid mosaic model
membrane dynamics is termed the fluid mosaic model because...
the membrane is seen as a mosaic of lipids and proteins which are free to move back and forth fluidly
according to the fluid mosaic model, lipids and proteins are free to...
diffuse laterally in two dimension, but never flip flop.
phosphlipid head groups and hydrophilic proteins are restricted from enetering...
the hydrophobic membrane interior
lipid bilayer membranes are said to have polarity because the inside face and the outside face of the membrane remain different
The cell membrane is called semipermeable because..
it is permeable to some substances and impermeable to others
The cell membrane is said to be selectively permeable because...
it is subject to modification and gets to decide what goes in it andleaves.
What regulates the cell's internal environment?
the cell membrane
the cell membrane is said to regulate the cell's internal environment because.....
the cell's permeability determines which substances enter and leave the cell.
A difference in concentration is called a ...
Moving "down" the concentration gradient means...
moving from an area of higher concentration to an area of lower concentration.
The phenomenon in which in a system of fluid, solute and solvent particles tend to disperse themselves so that solute concentration is uniform throughout the system is called...
osmosis refers to..
simple diffusion in which water, not the solute, moves across a membrane in an "effort" to equalze the concentration.
When one portion of a solution has a higher concentration than another, the region of higher concentration is said to be...
When one portion of a solution has a lower concentration than another, the region of lower concentration is said to be...
a cell in hypotonic solution will...
a cell in hypertonic solution will...
a cell in isotonic solution will...
remain the same at equilibrium
The process of simple diffusion and osmosis is passive, meaning....
they do not require the expenditure of energy
The solute moves towards equilibrium in...
the solvent moves towards equilibirum in....
facilitated diffusion is...
the movement of a sollute across a membrane, down a gradient, when the membrane itself is impermeable to that solute
what allows materials to cross the plasma membrane down a gradient in faciliatated diffusion?
specific intergral membrane proteins
what are two kinds of proteins that aid in the trasnportation of molecules in facilitated diffusion?
channel proteins and carrier proteins
Channel proteins and carrier proteins give what special feature to the cell membrane?
channel proteins in the plasma membrane allows...
material that cannot pass throught the membrane by simple diffusion to flow through the plasma membrane down a concentration gradient.
how do channel proteins allow materials through the membrane?
by forming a narrow openning in the membrane surrounded by the protein
Channels are very selective becuase...
they only let 1 type of ion to go through the channel
Ion channels are said to "gated" if...
the channel is open in response to specific environment stimuli
a voltage gated ion channel is..
a channel that opens in response to a change in the electric potential across the membrane
a ligand-gated ion channel is..
a channel that opens in response to a binding of a specific molecule
carrier proteins in facilitated diffusion transport materials by....
attaching to the molecule to be transported then undergoes a conformational change to move the molecule to the other side.
Uniports are carrier proteins that...
can only carry one molecule across the membrane at a time
symports are carrier proteins that...
can carry two moleclues across the membrane at a time
antiports are carrier proteins that..
can carry two molecules across the membrane at a time in opposite directions.
active transport is..
the movement of molecule through the plasma membrane against a gradient.
active transport is different from diffusion in a sense that...
energy is expended in active transport, where as in diffusion it is not.
active transport requires ....
active transport requires energy because...
it is working against a gradient
the active transport process is coupled to a process that is...
thermodynamically favorable (delta G < 0)
In primary active transport, the transport of a molecule is...
coupled to ATP hydrolysis
In secondary active transport, the transport of a molecule is...
not coupled to ATP hydrolysis
How is ATP used in secondary active transport?
It is first used to create a gradient, then the potential energy in the gradient is used to drive the transport of a molecule across the membrane.
the ATP use in which kind of active transport is considered to be indirect?
secondary active transport
a common mechanism driving secondary active transport of many different molecules involves...
coupling transport to the flow of sodium ions down a gradient
The Na+/K+ ATPase is...
a transmembrane protein in the plasma membrane of all cells in the body.
the activity of the Na+/K+ ATPase includes
pumping out 3 Na+ ions, pumping in 2 K+ ions and hydrolyzing one ATP to drive the pumping of the ions against their gradients
sodium that is pumped out by Na+/K+ ATPase does not...
come back in the cells
potassium that is pumped out by Na+/K+ ATPase can come back into the cell because of
potassium leak channels
resting membrane potential in Na+/K+ ATPase is..
an electric potential that is created across the plasma membrane when the movement of positive charge out of the cell leaves the interior with a net negative charge
what is the driving force behind secondary active transport?
the concentration gradient of high sodium outside of the cell established by the Na+/K+ ATPase.
What are the three important functions of Na+/K+ ATPase?
to maintain osmotic balance
to establish the resting membrane potential
to provide the sodium concentration gradient for secondary active transport.
active transport is a process by which substance cross the membrane aginst their gradients, meaning in terms of concentration they are going from ________ to _______.
lower to higher
a process to transport material outside of the cell in which a vesicle in the cytoplasm fuses with the plasma membrane and the contents of the vesicle are expelled into the exracellular space.
a process to transport material inside of the cell in which a invagination of a piece of the cell membrane forms a vesicles that holds the extracellular materials for transport to the interior of the cell.
The new vesicle that forms is endocytosis is called....
what are the three types of endocytosis?
the nonspecific uptake of large particulate matter into a phagocytic cell
what does the material in a phagocytic cell do latter after phagocytosis?
merge with a lysosome to be broken down
the nonspecific uptake of small molecules and extracellular fluid via invagination.(drinking cell)
What is the site of endocytosis marked by?
pits coated with the molecule clathrin and receptors that bind to a specific molecule
a buildup of plaque on the walls of the arteries
What are the three types of cellular adhesion?
how do tight junctions adhese cells?
linking together portions of adjacent cell membrane to form a barrier
there are no intercellular space at what kind of junction?
how do gap junctions adhese cells?
linking together the cytoplasms of adjacent cells
small particles are able to flow through which junction freely?
gap junction consists of which structual features?
protein channels that form a bridge between two cells
Desmosomes are composed of...
plaquelike proteins embedded in the cell membrane to which the cytoskelton is attached.
what is responsible for the structual integrity of most tissues in the body?
what are the three function of the nucleus?
contain and protect ane DNA
partial assembly of ribosomes
how many membranes surround the nucleus?
What are the two function of the mitochondria?
produce ATP via the krebs cycle
how many membranes surround the mitochondira?
what are the functions of ribosomes?
what is the two functions of the Rough ER?
location of synthesis
modification of secretory, membrane-bound and organelle proteins?
how many membranes surround the Rough ER?
What are the two function of the smooth ER?
detoxification and glycogen breakdown in liver
steroid sytnthesis in gonads
how many membranes does the Smooth ER have?
what are the two functions of the golgi apparatus?
modification and sorting of protein
how many membranes surround the golgi appartus?
what is the function of lysosomes?
contain acid hydrolases which digest various substances
how many membranes surround lysosomes?
what is the function of peroxisomes?
metabolize lipids and toxins using H2O2
how many membranes surround peroxisomes?
what are the components of the endomembrane system?
endoplasmic reticulum, nuclear membrane and the outer membrane
the Rough ER constitutes a principal site of ....
cellular protein synthesis
The smooth ER does not have ....
What is a speicalized derivative of the endoplasmic reticulum?
the golgi appartus consists of...
a series of flattened sacs
golgi completes transportation by
vesicles that pinch off from it and migrate to the cell surface then release by exocytosis
peroxisomes contain the enzyme...
senescent organelles are...
in plant cells lysosome house...
spaces and vacancies in the cytoplasm
vacuoules are typically filled with
what are the function of vaculous in protozoans?
expel wastes or excess fluid
mitochondria are organelles that mediate...
the synthesis of ATP
what molecule is associated with energy storage?
the inner mitochondrial membrane is folded into...
convolutions called cristae
the convolutions of folded inner mitochondrial membrane
the interior of the inner mitochondiral membrane is called...
what two things occur inside the mitochondria?
krebs cycle and oxidative phosphorylation
what processes produce the bulk of the ATP generated in aerobic organisms?
krebsy cycle and oxidative phosphorylation
Is all ATP produced inside the mitochondria?
no, some are produced outside of it during glycosis.
what is a precursor step to the kreb's cycle and oxidative phosphorylation?
glycosis takes places outside the...
the energy producing process that anaerobic organism can preform is...
anaerobic organisms cannot perform kreb's cycle or oxidative phosphorylation because..
it lacks a mitochondria
proccesses that depend on the mitochondira are considered to be...
Plastids are found almost solely in...
the most abundant of plastids in plants are...
cholorplasts contain the green pigment...
choromosomes reside in...
chromosomes are composed of..
DNA and proteins
what bears the genetic material of a cell?
what is the nucleolus?
a sub organelle located in the nucleus
what is the nucleolus the site of?
formation of ribosomal ribonucelic acid (rRNA)
What does rRNA function in?
the trnaslation of the genetic code
cilia and flagella are associated with..
what is the function of cilia in the human airway?
propel foreign particles toward the throat so things can be expelled or swallowed
cilia and flagella are composed of a structured arrangement of....
what is the main component of centrioles?
what is the function of the centriole?
assits in the formation of the mitotic spindle during cell division
what is the function of microtubules in the cytoplasm?
quasiskeletal structure for the cell itself (cytokeleton)
microtubles are formed of a protein called..
aside from microtubules serving as a cytoskeleton what serves as a secon elemeny of the cytoskeleton?
microfilaments are composed of a protein called...
microfilaments function as part of the cytoskeleton and..
receptors are integral membrane proteins that...
transmit signals from the extracellular space into the cytoplasm
the molecule that corresponds to the specific receptor is called a(n)...
a ligand is generally...
a hormone or a neuotransmitter
Singal transduction is ...
when a ligand binds to its receptor on the extracellular surface of the plasma membrane and triggers a response within the cell
what are the three main types of of signal-transducting cell surface receptors ?
ligand-gated ion channels, catalytic receptors, G-protein-linked receptors
ligand gated ion channels are located...
in the plasma membrane
ligand ion channels do what upon binding a particular transmitter?
open an ion channel
example of ligand ion channel process?
catalytic receptors are located where?
cytoplasmic side of the membrane
catalytic receptors' enzyme activity is initiated by...
ligand binding at the extracellular surfaces
the catalytic role of catalytic receptors is that of a protein called..
an enzyme that covalently attaches phosphate groups to proteins
an example of tyrosine kinase is..
what regulates the activity of proteins?
modification with phosphates
How does a G-protein-linked receptor transduce its signal to the cell?
with the aid of a second messenger.
The second messenger is...
a chemical signal that relays instruction from the cell's surface to enzymes in the cytoplasm.
The most important second messenger is...
cyclic AMP (cAMP)
why is cAMP known as the universal hinger signal?
it is the second messenger of the hormones epinephrine and glucagon which cause energy mobilization
secon messengers allow a greater ______ than receptors produce alone.
some enzymes are inactivated by..
one G-protein-linked receptor
one G-protein-linked receptor activates...
Each G-protein activates..
many adenylyl cyclase enzymes
each adenylyl cyclase enzymes makes...
lots of cAMP from ATP
each cAMP activates...
each cAMP-dpk phosphorylates..
many enzymes...activating some and inactivationg some.
the G-protein-linked receptors that have nothing to do with cAMP activate an enzyme called...
enzymes are ________.
Activation energy is the energy at the ....
a (an) _______ reduces a reaction's activation energy
Decreasing the activation energy ________ the reaction rate.
A ________ is unaltered in quantity and condition in a reaction.
Enzymes do not affect the _________ of reactants and products
The "lock and Key" theory correlates to...
most enzymes function at a pH between...
gastric enzymes function at a pH between....
most enzymes work best at the physiological temperature of...
Denaturation occurs when a protein comes in contact with ________ temps.
denaturated proteins put back into stable conditions will usually....
rate of a catalyzed reaction depends on the concentration of ______ and _______.
substrate and enzymes
each enzyme associates with its substrate at an....
Substrate A + Substrate B + Enzyme ---> _______________ ---> Enzyme + Products
inorganic substances (Fe2 or Cu2 ions)
Organic substances (vitamins)
enzymes are controlled by a process called...
Feedback inhibition is when an enzyme's activity may be inhibited by...
accumulation of product
feedback inhibition prevents the cell from producing...
an excessive quantity of product
competitive inhibition occurs when two molecules (the inhibitor and the substrate) compete for...
an enzyme's active site
____ is the form in which most cells store their energy
ATP (Adenosine triphosphate)
The molecular makeup of ATP includes the three components...
Adenine, Ribose and 3 phosphate groups
In ATP, the bonds that link the two phosphate group farthest from the adenosine moiety are...
No bond releases ______ when broken
The energy from bond disruption actually comes from...
the subsequent formation of bonds that are more stable.
the energy required to synthesize ATP is derived from...
glucose molecules stored in the cell
ATP is produced anaerobically via process of....
Glycolysis might be followed by two steps called...
fermentation (continues glycolysis)
Aerobic processes (Produces add'tl ATP)
Glycolysis breaks down a glucose molecule to yield...
two moleclues of pyruvate
glycolysis has a net gain of ___ ATP
___ ATPs are required for glycolysis
glycolysis produces __ ATPs
glycoylsis produces __ NADHs
NADH stores energy that will ultimately generate additional ATP if _____ is present