Cells and Organelles Flashcards
Cells are life’s fundamental unit of ___ and ____. They are the smallest unit of ____ that can perform all activities required for life
structure, function, organization
___ ____ was the first to discover the cell, when he observed the cell walls of dead cells when looking at ___ ___. This was made possible by the invention of the ___ decades earlier. Hooke names cells from the latin word ___, meaning small room. ___ _____ then enhanced microscope lenses and was the first to observe living cells. He saw that cells were ____ and concluded that they were alive.
robert hooke, tree bark, microscope, cella, van leeuwenhoek
The discovery of the cell helped form ___ ___ many years later by the contribution of several scientists. Conclusions made from studying __ and animals helped from the ___ ___ of cell theory
cell theory, plants, 3 tenets
the 7 tenets of cell theory: 1. all organisms are composed of ___ or more cells. 2. The cell is the __ __ of structure and organization in organisms, 3. All cells come from ____ ____, 4. the activity of an organism depends on the ___ ___ of independent cells, 5. Energy flow occurs ____ ____, 6. cells carry and pass on __ ____, 7. all cells of similar species have the same basic ___ ____.
one, basic unit, pre-existing cells, total activity, within cells, hereditary information, chemical composition
Some organisms are only a single cell, such as ___ or ___. Others are multicellular, like humans, and have groups of cells ___ and performing ___ ___.
bacteria, amoeba, coordinating, specialized tasks
all cells are bound by ___ ___, a selective barrier that separates its content from the __ ___. They also all contain ___ __ (DNA). They also all contain ____ that are not membrane bound and synthesize ____ ___ from the genetic material.
plasma membranes, outer environment, genetic material, ribosomes, functional proteins
Prokaryotic cells do not have a __ ___ ___ or organelles. _____ cells have generally a membrane bound nucleus and organelles
membrane bound, eukaryotic
the cell membrane protects the cell from its ____, and allows for the selective permeability of ___, ___ and other molecules in and out of the cell. It also allows for the _____ between the cells, and provides _____ ____ for the cell
environment, nutrients, waste, communication, structural support
The cell membrane is fundamentally made of a ___ __ that also contains ____ _____, ____, (animal cells) which promote membrane ___, and ____ (plant cells)
phospholipid bilayer, membrane proteins, cholesterol, fluidity, sterols
A phospholipid bilayer is made of ___ layers of phospholipid molecules with their ___ pointing towards each other. This makes up the majority of the cell membrane
2, tails
Phospholipids are made of 2 ___ __ and a ___ ___ attached to a ___ backbone. The head is ____, while the fatty acids are _____. This makes sure that only the ____ heads are exposed to aqueous environments inside and outside the cell. These phospholipids are made by the ___ ___ and are ____.
fatty acids, phosphate head, glycerol, hydrophillic, hydrophobric, polar, smooth ER, amphipathic
The more _____ and _____ a molecule is, the harder it is for molecules to pass through. Small hydrophobic molecules such as ___, ___, ___ can cross the cell membrane very easily. Small, ____ polar molecules such as ____, ___, ____and ___ can also pass through the membrane. Large uncharged polar molecules such as ___ and ____ cannot pass through the membrane alone without a ___ ___. ____ also cannot make it across the membrane alone.
charged, large, CO2, O2, steroids, uncharged, water, urea, ethanol, glycerol, glucose, sucrose, membrane protein, ions
The membrane is said to be a ____ because it is composed of multiple different parts like phospholipids and proteins. It is also said to be ____, because the cell membrane components are constantly shifting around. Within the bilayer, phospholipids frequently __ and move ___ within the same layer. Occasionally they also flip ____ from one side of the membrane to the other. Thus it is referred to as the __ ___ ___
mosaic, fluid, rotate, laterally, vertically, fluid mosaic model
The nucleus contains the cell’s ____ ____. It dictates what the cell does by controlling what ___ the cell makes, how it __ and when it ____. The nucleus is enclosed by a __ ____ nuclear ____, that have ____ that allows molecules to enter and exit. Inside is the ___ ___ a dense network of ___ __ that provide mechanical support that maintains the shape of the nucleus. The ____ is the region where ribosomes are made. Certain cells like ____ and __ ___ cells have multiple nuclei, while other cells like ___ ___ ___ and ____, do not have a nucleus
genetic materials, proteins, grows, replicates, double layer, envelope, pores, nuclear lamina, protein filaments, nucleolus, osteoclasts, skeletal muscles, red blood cells, platelets
In the nucleolus, ______ ____ is synthesized. Then ribosomal proteins are imported from the ____. These two components are combined into ribosomal ____, which are then transported to the cytoplasm for complete assembly
ribosomal RNA, cytoplasm, subunits
In eukaryotes, ____ are the general packaging of DNA and proteins, which makes the DNA easier to store in the ___. DNA is wrapped around proteins called _____. A package of DNA wrapped around a bundle of ___ histones is called a ____. ____ are tightly condensed organizations of chromatin. These are seen when the cell is undergoing ____. Humans have ___ chromosomes in total, ___ each from their mother and father
chromatins, nucleus, histones, 8, nucleosomes, chromosomes, mitosis, 46, 23
The cytosol is a ____ fluid inside the cell. It does not include the components suspended within it. The _____ is the are in which the cell’s ___ ___ occurs, and includes both the cytosol and the ___ suspended within, except the nucleus
gel-like, cytoplasm, metabolic activity, organelles
Ribosomes are essential to ____ ____ (translation), and are found in both __ and ___. They are composed of ___ and -__, and are composed of two subunits. In eukaryotes, these are the ____ and _____ which combine to make ____. In prokaryotes, these are the ___ and ____ which combine to make ____. Ribosomes are either free floating in the cytosol or bound to the ____ ____. Free floating ribosomes tend to make proteins that function within the __ of the cell while bound ribosomes make proteins that will be ____. They are not ___ __
protein synthesis, eukaryotes, prokaryotes, rRNA, proteins, 60S, 40S, 80S, 50S, 70S, rough ER, cytosol, exported, membrane bound
The endoplasmic reticulum is an extensive network of interconnected ____ with flattened areas known as ____. The ER membrane separates the cytosol from the ___ ___ and is continuous with the outer layer of the ___ ___.
membranes, cisternae, ER lumen, nuclear envelope
The rough ER is closest to the _____ and is continuous with the outer nuclear membrane. It has many ___ attached to it, giving it its rough appearance. Proteins can be synthesized on the rough ER ____, which are injected into the ___ of the ER where it can be ____ modified by adding additional groups. For example, ____ ____ are added to the proteins during ____. Additionally ______ ____ can be added. The proteins are also prepared for ____.
nucleus, ribosomes, ribosomes, lumen, post-translationally, sugar molecules, glycosylation, phosphate groups, transportation
The smooth ER is furthest from the nucleus and has no ____. It synthesizes ___ and ____ ___. In ___ cells, it breaks down ___ from cellular reactions and drugs. In smooth and striated muscles, the smooth ER is called the ___ ___ and it stores and releases ions like ___.
ribosomes, lipids, steroid hormones, liver, toxins, sarcoplasmic reticulum, calcium
After proteins are synthesized, they are transported to the __ ___. The golgi is series of flattened membrane sacs called _____ that ___, ____ and ____ proteins. They modify proteins by _____ polypeptides, and adding ___ or ____ groups, but do not create proteins. They then package the proteins into ___ to be transported elsewhere. The golgi also makes ____ and occasionally transports ____.
golgi apparatus, cisternae, sorting, modification, transportation, glycosylating, sulfate, phosphate, vesicles, lysosomes, lipids
The golgi has a ____ face, which is closest to the ER for ___ ____, and a ___ face, for ____ vesicles.
cis, incoming vesicles, trans, secretory
Lysosome are membrane bound vesicles made by the ____, that are very ____ on the inside. They contain __ ___ that allow them to break down ___ and other cellular debris. It participates in ____ by releasing its contents internally, as well as ____, which is when they fuse with damaged ___ to break them down and recycle them. It also fuses with a ___ ___ to break it down into useful ____. It also breaks down ___ and found in high concentrations in ____
golgi, acidic, digestive enzymes, macromolecules, apoptosis, autophagy, organelles, food vacuole, nutrients, pathogens, phagocytes
Peroxisomes are membrane bound organelles commonly found in the ____ and _____. They generate ___ ___ to oxidize substances, and also break it down by using the enzyme ___. They also break down ___ ___, and __ ___ and help to inactivate __ ___
liver, kidney, hydrogen peroxides, catalase, fatty acids, amino acids, toxic substances
Vacuoles are large vesicles inside cells that ___ and __ materials and are membrane bound. ___ vacuoles move materials between organelles, ___ vacuoles are nutrient filled and transport food, and fuse with lysosomes to have the food broken down.
store, move, transport, food,
___ vacuoles are only in cells and are very large, and take up most of the inside of the plant cell. They store large amounts of water and ____, and exert ____ which helps maintain the cell rigidity by pressing up against the ___ __. ____ vacuoles collect and pump excess water out of the cell to prevent it from ____. These are commonly found in _____ environments like ___.
central, nutrients, turgor, cell wall, contractile, bursting, hypotonic, protists
The cytoskeleton is a network of ____ and___ within the cytosol. It maintains cell _____ and provides ___ ___. It facilitates the movement of components within the cell by providing a ___ ___ that the substances can travel on, it promotes __ ____, and it can be used to anchor and stabilize __ ___. There are 3 main components, the ___, ___ ___, and ___
tubules, filaments, shape, mechanical support, railroad network, cell motility, membrane proteins, microfilaments, intermediate filaments, microtubules
microfilaments are two intertwined polymer strands of ___. They are involved in ___ ___, as well as __ __ ___. They help to form the amoeba ____, which is a projection from a cell that is used in movement and digestion. They also form the __ __ that is involved in separating cells in mitosis
actin, cell motility, skeletal muscle contraction, pseudopod, cleavage furrow
Intermediate filaments are tubes of intertwined, coiled ____. Depending on the ___ of cell, the protein differs. _____ is an example that is found in abundance in the skin. Intermediate filaments provides support for maintaining __ __
proteins, type, keratin, cell shape
Microtubules are hollow tubes made from polymers of the protein ____. They provide ___ and ___ for cellular activities by forming the railroad network. They also form the __ ___ which guides chromosomes during cell division.
tubulin, support, motility, spindle fibers
Microfilaments are the ____, intermediate filaments are in the middle and microtubules are the ____, in terms of their diameters.
smallest, largest
Bundles of microtubules also make up other structures such as the ___, which are short, hair like extensions from the cell for movement, ____, which are thread like extensions from the cell for movement, and ___.
cillia, flagella, centrioles.
For cells that are part of tissues held in place, cillia help move substances in the ___ across the cell surface. For example, cilliated cells in the __ ___ help to move debris trapped in the ___ out of the airway. The motion is ____ sweeping
environment, respiratory tract, mucus, back-and-forth
Flagella are longer ______ projections from a cell. Their motion is ___ and __ to the direction of the cell
thread-like, whiplike, parallel
Microvilli are membrane projections composed of an ___ ____ ___which help maintain its shape. They look like small fingers that emerging from the __ surface of a cell. They function to increase the __ ___ of cells, and are common in the cells of the ___ ___ where they aid in absorbing ___, and enhance absorption and ___.
actin filament cores, apical, surface area, digestive system, nutrients, secretion
Centrioles do not have a ____. They are ____ ___ ___, which means microtubules emerge from them. Centrioles are found ___ to each other in a pair called a ____. These pairs are responsible for forming the __ ___ during cell division.
membrane, microtubule organizing centers, perpendicular, centrosome, spindle apparatus
another MTOC is the __ __, which are found at the base of each ___ and ___. These help microtubules to ___ and emerge from them
basal bodies, cillium, flagellum, develop
MTOCs have a ___ array. They are made of nine ___ of microtubules, held together by supporting ___
9x3, triplets, proteins
Plant cells have MTOCs, but they do not have ____. Instead they use an organelle called a ___ __ __
centrosomes, spindle pole bodies
The mitochondria plays an essential role in creating ____ ____ to drive cellular activities. It has a __ ___. The outer membrane is ___ and encompasses the entire mitochondria. The -_ ____ is an area between the outer membrane and the inner membrane. The inner membrane is ____ to increase surface area, and these folds are called ___. The ___ ____ is the space enclosed by the inner membrane.
chemical energy, double membrane, smooth, intermembrane space, folded, cristae, mitochondrial matrix
The higher the ___ __ of the cell, the more mitochondria the cell has. The mitochondria contains its own ___ ___ that replicates independently, and ___. The mitochondria synthesize _____, and are the site of ____ (fatty acid ____/breakdown)
energy needs, circular DNA, ribosomes, ATP, beta-oxidation, catabolism
Chloroplasts also have a ___ ___, and are only present in cells capable of _____ such as ___ and ___. They allow __ ___ to be used to produce sugar. They absorb ___ and __ light and reflect ____ light, which gives it their green appearance. Chloroplasts also contain their own __ ___, and are most likely descended from a bacteria capable of photosynthesis called ____.
double membrane, photosynthesis, plants algae, light energy, red, blue, green, circular DNA, cyanobacteria
the __ ____ states that the mitochondria and chloroplasts were once ___ ___ that lived on their own. They were absorbed by larger cells and formed a ____ relationship with them, receiving protection and giving _____. They eventually became ___ in eukaryotes
endosymbiotic theory, independent prokaryotes, symbiotic, energy, organelles
Evidence for the endosymbiotic theory is that mitochondria and chloroplasts have their own ___ in the form of ___ DNA, which is similar to ___ DNA, rather than the ___ eukaryotic DNA. They also are about the same ___ as prokaryotes and divide by ___ ___ rather than mitosis, and ___ of the eukaryotic cell they reside in. They also contain other structures similar to ____.
genome, circular, prokaryotic, linear, size, binary fission, independently, bacteria
Plant cells have a rigid ___ ____ while animal cells do not. As a result, animal cells are more ___ in shape, while plant cells are more ___ in shape. Animal cells have ____ while plant cells do not.
cell wall, circular, square, centrioles
Plastids are a group of organelles including _____, ____, which store nutrients, and _____, that store plant pigments. They are only in plant cells
chloroplasts, leucoplasts, chromoplasts,
storage vacuoles store ___, ___ and toxic substances like ___, only in plant cells
starch, pigments, nicotine
Cell walls are found in ___, ___, ___, and ____.
plants, fungi, protists, bacteria
___ proteins are attached loosely to one surface from one side of the membrane, but not ___ in it. They are mostly ___ and held in place with ___ bonds, and ____ interactions. To detach it, you would need to change the ___ concentration or the ___.
peripheral, embedded, hydrophilic, hydrogen, electrostatic, salt, pH
___ membrane proteins are embedded into the membrane itself. A ___ protein is a type of integral protein that goes all the way through the membrane on both sides, and allow substance to move in and out of the cell. Both are mostly ____. To remove one from the membrane you would have to use a _____ to destroy the membrane and expose the protein.
integral, transmembrane, hydrophobic, detergent
_____ proteins allow for the passage of substances across the membrane. The different types of transport proteins depending on the ___ and what is able to pass through. ____ proteins are hollow openings that allow substances to pass directly through. For example, ____ allow water to move into and out of the cell more quickly. ____ channels are an example of a channel proteins. They may be ___ __, ___ ____ (respond to differences in charge across the membrane), ___ ___ (open in response to changes in pressure, temperature, vibration), and ___ ___ (a signalling molecule binds and opens the channel). ____ proteins are a type of transport proteins that binds a molecule then changes ___ to allow the molecule to enter. ___ enters via carrier proteins
transport, structure, channel, aquaporins, ion, always open, voltage gated, mechanically gated, ligand gated, carrier, shape, glucose
___ proteins will bind to signalling molecules which then transmits changes to the inside of the cell
receptor
glycoproteins are proteins with a _____ group attached. They function in _____ ___, such as when an immune cell checks if a cell is part of the organism. It also functions in ___ ___, as some glycoproteins can act as receptors by binding to signalling molecules. They are also used in cell ___ by binding to molecules outside the cell to help ___ them.
carbohydrate, cell-to-cell communication, cell signalling, adhesion, stabilize
Some membrane proteins are ___ which help to accelerate chemical reactions
enzymes
Membrane proteins can also be involved in attaching cells to ____ cells, and to other ___ and ___ inside and outside the cell, for stability, and ___ ___.
adjacent, proteins, filaments, cell communication
___ ___ form a seal between adjacent cells, ensuring there are no gaps or spaces for materials to pass in between them. This means materials must enter the cells ___ in order to pass through the tissue. For example, in the digestive system, tight junctions are used to keep in ___ ___, and proper __ ___. They are also found in the __ ___ ___, which helps to keep the brain isolated from potentially harmful substances in the body
tight junctions, directly, digestive enzymes, nutrient absorption, blood brain barrier
____ junctions form a thick band that extend across the cell and attaches them to adjacent cells, helping them to organize them into ___. For example, the cells that line the __ __ have adherence junctions to ensure a __ ___ between them to maintain blood vessel integrity. They are also attached to ___ __inside the cell to further stabilize them
adherens, tissues, blood cells, continuous connection, actin filaments
_____ connect adjacent cells to each other, but are a much ___ connection than adherens junctions. They tend to be found in tissues exposed to a lot of ____ ___. For example, the outer layer of the ___ and ___ __ have many desmosomes to prevent them from being separated. Desmosomes are attached to ___ ___ like keratin which are in the inside of the cell for ___
desmosomes, stronger, mechanical stress, skin, cardiac muscles, intermediate filaments, reinforcement
____ look like half a desmosome. They have similar structure and are also connected to __ ___ on the inside of the cell. However, they do not connect cells to adjacent cells. They attach cells to the ___ __, usually to a specific structure called the ___ ___. They help ___ a cell and hold them in place, preventing them from detached from a surface easily. Hemidesmosomes are found in the _____ of the skin.
hemidesmosomes, intermediate filament, extracellular matrix, basement membrane, stabilize, epidermis
___ ____ form narrow tunnels between cells that allow for effective cell-to-cell communication by allowing the passage of __ __ and ___ between adjacent cells. They also allow for a smooth ____ __ ___ to spread through tissues like the -__, because ions like ____ can spread directly from one cardiac muscle cell to the next, resulting in a coordinate heart contraction.
gap junctions, small molecules, ions, synchronized electric signals, heart, sodium
The side of the cell facing the external environment or internal cavity; not attached to anything else
apical surface
The sides of the cell; in tissues, sides will be touching cells adjacent to it
lateral surface
opposite to the apical surface, and bound to the underlying connective tissue like the basement membrane
basal surface
A structure that sits outside the cell that helps to anchor and support the cells attached to it
basement membrane
Type of transport where no energy move substances; move from area of higher to lower concentration
passive transport
When energy is required to move substances; against their concentration gradient
active transport
A passive transport type; net movement of substances down their concentration gradient directly through the cell membrane
simple diffusion
type of passive diffusion; Like simple diffusion but with the assistance of a specific transmembrane transport protein
facilitated diffusion
active transport that uses ATP directly to move a substance against its concentration gradient
primary active transport
active transport that uses an established electrochemical gradient to move a substance against its concentration gradient; can be used to move molecules in the same and different directions
secondary active transport
In _____, substances are brought into the cell by enfolding them with cell membrane. This surrounds the substances into a ____. These substances can be moved out of the cell through ____, where vesicles are fused with the __ ___, causing the substances to exit the cell. Increasing the concentration of ____ will trigger exocytosis, for example when neurons release ___ or endocrine cells release ___ into the bloodstream
endocytosis, vesicle, exocytosis, cell membrane, Ca2+, neurotransmitters, hormones
____ is a type of cell endocytosis in which particles are engulfed by extending structures like ____. They are packaged into a ___ and can be ___ or broken down later.
phagocytosis, pseudopods, vesicle, fused
____ is a type of cell endocytosis in which a cell continually _____ ___ ___ and whatever substances are in it into small vesicles. The solutes are dissolved in ___ and taken up into the cell. This is a _____ process
pinocytosis, drinks extracellular fluid, droplets, non-selective
___ _____ is a type of endocytosis in which molecules outside the cell bind to ___ on the cell membrane. Then, a protein called ____ will bind to areas of the membrane that have bound receptors on the inside. These proteins form a ___ that pulls the membrane inward and creates a ___. in the end, the proteins detach.
receptor-mediated endocytosis, receptors, clathrin, lattice, vesicle
A solution with very low concentration
hypotonic
solution that has the same concentration
isotonic
a solution that has a high concentration
hypertonic
A plant cell is usually in a ____ environment, so most of the time, more water is ____. However, since the cell is surrounded by a ____ ____ ___, it doesn’t burst, and remains in a swollen state, called ___. The __ __ which is responsible for holding large volumes of water, is enlarged due to large volumes of water in the cell
hypotonic, entering, stiff cell wall, turgid, central vacuole
A plant cell in an isotonic environment is ____.
flaccid
A plant cell wall in a hypertonic environment, will ___ __ from its ___ ___, but the latter will remain in place.
pull back, cell wall
Cell walls are an additional layer outside the ___ ____ for support and ____. They are found in ___, ___, ___ and ___.
plasma membrane, protection, bacteria, fungi, plants, protists
Bacterial cells walls are made of ____ and are either ____ or ____. plant cell walls are made of ___, and fungi cell walls are made of ___
peptidoglycans, gram-negative, gram-positive cellulose, chitin
a gram negative bacteria have very ____ peptidoglycan layer, while a gram positive bacteria has a ____ one. Gram negative bacteria have an ___ and ___ membrane, while a gram positive bacteria only have one membrane. Gram negative bacteria have a structure called a ________ embedded in their outer membrane, and when the bacteria is destroyed, these structures are released as a toxic compound called ___, which can trigger an __ ___.
thin, thick, inner, outer, lipopolysaccharides, endotoxins, immune response
The glycocalyx is a layer of ___ that coats the outer surface of some bacteria and animal cells. It is made up of a ___ ___ or a ____, and provides a physical barrier that shields the cell from ___ or ___ damage to prevent pathogens from being able to enter the cell. It primarily functions for ____ ____ and ___. It can also be found on the inside of __ ___, where it provides a protective barrier and maintains the __ ___.
carbohydrates, slime layer, capsule, chemical physical, cell-to-cell communication, adhesion, blood vessels, vascular walls
The _____ ____ is an external network found in animals in the area surrounding cells beyond the plasma membrane and glycocalyx. It is a network composed of ___ __ __, ___ __ and ____.
extracellular matrix, fibrous structural proteins, adhesion proteins, polysaccharides
The ECM functions to provide __ ___, ___ __ and __ ___. It provides support from its ___ ___. It participates in cell adhesion by serving as an ____ for cells to attach to. Finally it also functions in cellular communication both _____, by moving the cellular matrix and transmitting a signal to the cells attached to it, and ___ by serving as a ___ for __ __ to attach to, and acting as a ___ that holds signalling molecules and prevents them from being ___, allowing them to bind cells in a more controlled way and for ___ periods of time
structural support, cell communication, cell adhesion, support proteins, anchorage, mechanically, chemically, scaffold, receptor proteins, reservoir, degraded, longer
The components of the ECM: _____ and ___ are proteins that have carbohydrate groups attached. The groups attached to the former are ___ and ____, and mostly used for cell signalling and adhesion. In the latter, the carbohydrate groups are __ and ___, and have more of a role in ___ __
glycoproteins, proteoglycans, short, branched, long, unbranched, structural support
Components of the ECM: ______ is a protein that attaches the rest of the components of the ECM to ___, which are proteins integrated in the cell membrane. This faciliates cell ____
fibronectin, integrins, adhesion
Components of the ECM: ___ is the most abundant protein in mammals. It is found in ___, ___, __ and ___, in areas that need lots of structural strength. Every third amino acid in its sequence is a _____. It also has a ____ ___ structure, which gives it its structure. These are eventually arranged into collagen ___ that are ___ and bundled together for even more strength
collagen, bone, muscles, skin, tendons, glycine, triple helix, fibers, cross-linked
Microtubules extend throughout the cell and provide the ___ along which __ and ___ are transported using motor proteins
tracks, organelles, vesicles
____ is a motor protein that binds to the whatever it is transporting on one end, and walks along the ___ on its opposite end. It moves from the ___ of the cell to the ____.
kinesin, microtubule, center, periphery
____ is a motor protein that functions like kinesin, but moving from the ___ of the cell to the ____.
dynein, periphery, center
___ is the streaming movement of the cytoplasm within the cell. This circulates cytoplasm around the cell, allowing __ ___ to be moved around. This motion is created by the contracting and relaxing movements of ___ and ____ filaments of the cell ____.
cyclosis, cellular components, actin, myosin, cytoskeleton
