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
