MODULE 1.1 Flashcards
Types of Specialized Cells (4)
- epithelial cells
- bone cells
- cells of the immune system
- blood cells
a Dutch shopkeeper who had great skill in crafting lenses
Antony van Leeuwenhoek (1600s)
Despite the limitations of his now-ancient lenses, __________ observed the movements of ______ (a type of single-celled organism) and ______, which he collectively termed “__________.”
Antony van Leeuwenhoek;
protista and sperm
animalcules
Who coined the term “cell” for the box-like structures he observed when viewing cork tissue through a lens? And in what publication?
Robert Hooke, Micrographia (1665)
In the 1670s, ___________ discovered bacteria and protozoa.
van Leeuwenhoek
By the late 1830s, botanist ________ and zoologist _______ were studying tissues and proposed the unified cell theory
Matthias Schleiden and Theodor Schwann
Schleiden and Schwann proposed __________ as the method for cell origination, but it was later disproven.
spontaneous generation (also called abiogenesis)
_________ famously dispelled the theory of spontaneous generation by proving that living things do not come from nothing.
Rudolf Virchow
“Omnis cellula e cellula”
“All cells only arise from pre-existing cells”
Rudolf Virchow
Each cell is surrounded by a _____ and contains parts called __________
membrane;
cellular organelles.
Prokaryotic Cells Parts (8)
- plasma membrane
- cytoplasm
- cytoskeletal proteins
- ribosomes
- nucleoid
- plasmids
- glycocalyx
- cell extensions
Unlike eukaryotic cells, which has a cytoskeleton, prokaryotic cells such as the rod-shaped bacteria and archaea possess ___________ that function similarly to the cytoskeleton of eukaryotic cells. This scaffolding provides structural support to the cell and plays a role in cell division
cytoskeletal proteins
It is essentially the “bag” that holds all of the intracellular material and regulates the movement of materials into and out of the cell.
Plasma Membrane
In replacement of the nucleus, prokaryotic cell has the __________ which is the region of the prokaryotic cytoplasm that contains the genome—the main genetic material (DNA) of the cell and typically have a single, circular chromosome.
nucleoid
These are the tiny protein-making machines that carry out the genetic instructions of the cell.
Ribosomes
is a non-essential piece of DNA that confers an advantage to the bacteria, such as antibiotic resistance, virulence (the ability to cause disease) and conjugation (a bacterium’s ability to share this with other bacteria).
Plasmid
is a layer outside of the cell wall, and present in some bacteria.
glycocalyx
There are two types of glycocalyces which are the
slime layers and capsules.
help bacteria stick to things and protect them from drying out, particularly in hypertonic environments.
slime layers
These are long whip-like extensions that help bacteria move about the environment
Flagella
allow bacteria to stick to things, but have the added benefit of helping encapsulated bacteria hide from the host’s immune system.
capsules
are made of delicate protein strands and there are several different type associated with bacteria, including flagella and endoflagella.
cell extensions
These are also flagella but are wrapped around corkscrew-shaped bacteria and move in waves making the bacteria spin
Endoflagella (axial filaments):
Unlike plant cells, animal cells do not have a cell wall. Instead, multicellular animals have other structures that provide support to their tissues and organs, such as ______ and _________.
skeleton and cartilage
It is a non-membranous structure involved in the synthesis of ribosomes. It is within the nucleus and the nucleus has one or more nucleoli.
Nucleolus
t is a material consisting of DNA and proteins, and is visible in a dividing cell as individual condensed chromosomes.
chromatin
is a network of flattened, membrane-bound sacs and tubes that are involved in the production, processing, and transport of proteins that have been synthesized by ribosomes.
Endoplasmic Reticulum
is involved in some protein production, protein folding, quality control and dispatch.
Rough ER
is associated with the production and metabolism of fats and steroid hormones
Smooth ER
, receives proteins from the ER and folds, sorts, and packages these proteins into vesicles
Golgi apparatus
These are specialized vesicles that contain digestive enzymes and are used extensively within the cell for metabolism and transport of large molecules that cannot cross the membrane unaided.
waste disposal/recycling department of the cell
Lysosomes
There are three types of cytoskeletal filaments
microfilaments, microtubules, and intermediate filaments
the organelle with various specialized metabolic functions and produces hydrogen peroxide as a by-product, the converts it to water.
Peroxisome
These are projections that increase the cell’s surface area.
Microvilli
This is the region where the cell’s microtubules are initiated and it contains a pair of centrioles.
Centrosome
It is the motility structure present in some animal cells, composed of a cluster of microtubules within an extension of the plasma membrane.
Flagellum
Plant cells are differentiated from the animal cells by their (3)
cell walls, chloroplasts, and central vacuole
plant cells are ___________ because they use light energy from the sun to produce glucose
photoautotrophic
The cell wall then pushes against the walls of other
cells, creating a force known as
turgor pressure
Parts of chloroplasts (2)
stroma
thylakoid
It is a fluid matrix at the center of the chloroplast that is enclosed by the double membrane
Stroma
These are flattened disks within the stroma, and when stacked, is called _____.
thylakoids; grand
Thylakoids have a high concentration of _________ and __________ , which are pigments that capture light energy from the sun.
chlorophyll and carotenoids
is a small sphere of plasma membrane within the cell that can contain fluid, ions, and other molecules.
vacuoles
are essentially just large vesicles.
is a flexible layer formed on the outside of a growing plant cell.
Primary cell wall
a tough, thick layer formed inside the primary plant cell wall when the cell is mature.
Secondary cell wall
In plants, the cell wall contains mainly ______, along with other molecules like hemicellulose, pectin, and lignins, unlike bacterial cell wall which contains ___________.
cellulose;
peptidoglycan
cytoplasmic channels through cell walls that connect the cytoplasms of adjacent cells.
Plasmodesmata
– This is done by having visible light pass through the specimen and then through glass lenses
Light Microscopy
The three important parameters in Light Microscopy
magnificaiton
resolution
contrast
(ratio of an object’s image size to its real size
magnification
clarity of image
resolution
accentuates differences in parts of the sample
contrast
Different Types of Light Microscopy (8)
- Brightfield(unstained specimen)
- Brightfield (stained specimen)
- Phase-contrast
- Differential-interference-contrast(NOMARSKI)
- Fluorescence
- Confocal
- Deconvolution
- Super-resolution
– It focuses a beam of electrons through the specimen or onto its surface
Electron microscopy
Two Types of Electron Microscopy:
Scanning electron microscopy (SEM)
Transmission electron microscopy (TEM)
is useful for a detailed study of the topography of a specimen. The electron beam scans the surface of the sample, usually coated with a thin film of gold. The beam excites electrons on the surface, and these secondary electrons are detected by a device that translates the pattern of electrons into an electronic signal to a video screen. The result is an image of the specimen’s surface that appears three dimensional.
Scanning EM
It is used to study the internal structure of cells. It aims an electron beam through a very thin section of the specimen, similar to the way a light microscope transmits light through a slide. The specimen has been stained with atoms of heavy metals, which attach to certain cellular structures, thus enhancing the electron density of some parts of the cell more than others. The electrons passing through the specimen are scattered more in the denser regions, so fewer are transmitted. The image displays the pattern of transmitted electrons.
Transmission EM
The process takes cells apart and separates major organelles and other subcellular structures from one another.
Cell fractionation
Instrument used in cell fractionation
centrifuge
At cell fractionation, each speed, the resulting force causes a fraction of the cell components to settle to the bottom of the tube forming a ______. Which at lower speeds , consists of larger components, and higher speeds with smaller components.
pellet
This is for preparing cell components in bulk and identifying their functions, a task not possible with intact cells.
Cell Fractionation
