Studied by 11 people
What is resolving power and why is it important in biology?
The ability of a microscope to clearly distinguish between two plants.
How does an electron microscope work and what is the difference between a scanning (SEM) and transmission (TEM) electron microscope?
SEM - focuses on beams of electrons (e-) onto the surface of a specimen—looks 3D TEM - Focuses on beams of electrons (e-) through a specimen (cannot be alive) - shows internal detail
(Prokaryotic Cell) Bacterial chromosome
"The bacterial chromosome is one long, single molecule of double stranded, helical, supercoiled DNA" - https://bio.libretexts.org
(Prokaryotic Cell) Fimbriae
attachment structures on the surface of some prokaryotes
(Prokaryotic Cell) Nucleoid
region where the cell's DNA is located (not enclosed by a membrane)
(Prokaryotic Cell) Ribosomes
complexes that synthesize proteins
(Prokaryotic Cell) Plasma Membrane
membrane enclosing the cytoplasm
(Prokaryotic Cell) Cell Wall
rigid structure outside the plasma structure
(Prokaryotic Cell) Capsule
jelly-like outer coating of many prokaryotes
(Prokaryotic Cell) Flagella
locomotion organelles of some bacteria
Why is surface area to volume such an important concept as it applies to the size of a cell?
As SA:V ratio decreases diffusion slows down and becomes less efficient—the ratio goes down as the cell grows
How can some organelle depict evolutionary origins?
Endosymbiotic Theory - hypothesizes that some of the organelles in eukaryotic cells were once prokaryotic microbes. Mitochondria and chloroplasts are the same size as prokaryotic cells and divide by binary fission. Mitochondria and chloroplasts have their own DNA which is circular, not linear.
(Nucleus) Nuclear Envelope
houses chromosomes, contains nucleoli, has pores that regulate entry/exit of proteins and RNA, has a double membrane
(Nucleus) Nuclear Lamina
mechanically supports nuclear envelope, thus maintaining shape of the nucleus; has net-like array of protein filaments (in animal cells, these protein filaments are called intermediate filaments)
(Nucleus) Chromosomes
consist of coiled up discrete units of DNA—long DNA molecule + many proteins
(Nucleus) Chromatin
complex of uncoiled, long strands of DNA and proteins that make up chromosomes; is usually diffuse but condenses during cell division
(Nucleus) Nucleolus
site of ribosomal (rRNA) synthesis (with proteins), adjoins part of chromatin, made of densely-strained granules and fibers
Ribosomes
assemble site of protein synthesis, made of rRNA + proteins; translates mRNA "messages" to create the primary structures of proteins "While both types of ribosomes are used to make proteins, the difference between them has to do with the fate of the proteins. Cytosolic ribosomes make proteins for the cytosol, which rough endoplasmic reticulum ribosomes make them to be bound in membranes, or to be excreted from the cell in vesicles (exocytosis)." - varsitytutors.com
Smooth Endoplasmic Reticulum
LACKS RIBOSOMES, synthesizes lipids, metabolizes carbohydrates, detoxifies drugs/toxins, stores Calcium (Ca+) ions
Rough Endoplasmic Reticulum
HAS RIBOSOMES, secretes glycoproteins (proteins with carbohydrates covalently-bonded to them, hence the prefix), distributes transport vesicles, creates membranes for itself or other components of the endomembrane system has membrane that separates glycoproteins from the cytosol
Golgi Complex/Apparatus
modifies, stores, and sends products (proteins and phospholipids) of the ER; makes its own macromolecules; sorts and packages material into transport vesicles
Lysosomes
digest macromolecules through membrane sacs with hydrolytic enzymes, recycles organelles (autophagy), carries out apoptosis with mitochondria, performs phagocytosis
Apoptosis
"Apoptosis is the process of programmed cell death" - genome.gov
Phagocytosis
"Amoebas and many other unicellular eukaryotes eat by engulfing smaller organisms or food particles" - Campbell Biology
Vacuoles (General)
large vesicles from ER & golgi complex/apparatus
Food Vacuoles
formed through phagocytosis, fuse with lysosomes
Contractile Vacuoles
found predominentaly in protists and unicellular algae that live in freshwater; osmoregulate (pump out excess water)
Central Vacuole w/Tonoplast
(in plant cells) membrane that separates vacuole from cytoplasm, holds water (turgor pressure) and organic compounds,
(Central Vacuole) Cell Sap
"The solution inside the central vacuole that is the plant cell’s main repository of inorganic ions, including potassium and chloride." - Campbell Biology
Endomembrane System
group of membranes and organelles in eukaryotic cells that work together to modify, package, and transport lipids and proteins
The Endomembrane System includes:
nuclear membrane, smooth & rough ER, golgi apparatus, lysosomes, various vesicles/vacuoles, cell/plasma membrane
Mitochondria
site of cellular respiration (for energy production)
(Mitochondria) Mitochondrial Matrix
gel-like material where the citric acid cycle occurs, included by inner membrane contains enzymes, mitochondrial DNA + ribosomes dynamic state of flux AKA can move and adjust a lot to meet needs of cell
(Mitochondria) Cristae
folds of inner membrane that provide large amount of surface area for chemical reactions to occur
Plastids
a family of plant organelles that DO NOT EXIST IN ANIMAL CELLS
(Plastids) Amyloplast
plastids that produce and store starch in plants; (colorless)
(Plastids) Chromoplast
colored plastids (OTHER THAN CHLOROPLASTS) typically containing yellow (lutein) and green (carotene) pigment
(Plastids) Chloroplast
photosynthesis—contains chlorophyll
(Chloroplast) Thylakoid
interconnected, flattened sacs with chlorophyll where light reactions take place Granum - stacked thylakoids
(Chloroplast) Stroma
colorless fluid surrounding grana (stacked thylakoids) within chloroplast where "dark" reactions take place; contains chloroplast DNA + ribosomes + enzymes
Peroxisome
metabolic compartment w/ single membrane (it is a membrane-bound organelle; has enzymes that remove hydrogen atoms from substrates and then add oxygen atoms to form hydrogen peroxide (H2O2)—THIS IS THEIR NAMESAKE; breaks down fatty acids into smaller molecules for mitochondria (and therefore cellular respiration)
(Peroxisome) Glyoxysome
(in certain fat-storing tissues of plant seeds) specialized peroxisomes that convert fatty acids into sugar
Cytoskeleton (General)
fiber network throughout cytoplasm mechanical support, maintains shape anchors organelles + enzymes easily reassemble-able cell motility (movement) w/ help of motor proteins manipulates cell (plasma) membrane
(Cytoskeleton) Microtubules
hollow tubes (made of tubulin, or globular proteins) maintain shape of cell, movement of organelles & chromosomes guides vesicles separates chromosomes during cell division
(Microtubules) Centrosomes & Centrioles
help organize microtubule assembly Centrioles - 9 sets of triplet microtubules in ring arrangement that come in pairs PLANT CELLS LACK BOTH CENTROSOMES AND CENTRIOLES
(Microtubules) Cilia and Flagella
microtubule-containing extensions on some cells for locomotion of cell itself or move substances across cell cilia move like oars, flagella move w/ single undulations (think ocean snakes) both are anchored to cell by basal bodies cilia come in large numbers VS flagella single or in small numbers most animals cells a primary cilium with an "antenna" function instead of locomotion
(Microtubules) Dynein Walking
motor proteins that cause microtubules to move and allow organelles or cells to bend
Microfilaments
thin, solid rods made of twiste actin double chains; bears tension
(Microfilaments) Actin
globular proteins where microfilaments are formed
(Microfilaments) Cortex
outer cytoplasmic layer of a cell; has semi-solid consistency (like gel) due to the network of microfilaments
(Microfilaments) Pseudopodia
"false foot" actin and myosin work together to cause movement "The cell crawls along a surface by extending cellular extensions called pseudopodia and moving toward them" - Campbell Biology
(Microfilaments) Cytoplasmic Streaming
actin proteins allowing for movement of cytoplasm in a circular flow within large plant cells facilitates movement of organelles + materials within cell
Intermediate Filament
in terms of size, microfilaments < intermediate filaments < microtubules ONLY FOUND IN ANIMAL CELLS, bears tension is more "permanent" i.e. is not deconstructed and reconstructed as much cages the nucleus (mentioned in nuclear lamina flashcard)
Cell Wall (General)
extracellular structure of PLANT CELLS protects, maintains shape, prevents excess water (some other organisms have cell walls but not animals)
(Cell Wall) Primary Cell Wall
young, thin, flexible cell wall
(Cell Wall) Middle Lamella
pectin (a sticky polysaccharide) layer between adjacent cells, essentially a "glue"
(Cell Wall) Secondary Cell Wall
strong, double matrix that adds support to the primary cell wall NOT ALL PLANT CELL HAVE SECONDARY CELL WALLS
Extracellular Matrix (ECM) (General)
glycoproteins + other carbohydrate-containing molecules
(ECM) Collagen
most abundant glycoprotein; forms strong, long fibers outside cells—strengthens tissues and adds structural integrity
(ECM) Proteoglycans
made up with carbohydrates (95%), interwoven with collagen fibers
(ECM) Fibronectin
an ECM glycoprotein that acts as bridges between integrins and other ECM glycoprotein (such as collagen)
(ECM) Integrin
receptor proteins embedded in cell/plasma membrane "integrins are in a position to transmit signals between the ECM and the cytoskeleton and thus to integrate changes occurring outside and inside the cell" - Campbell Biology
What are intercellular junctions and why are they important?
Interactions that enable communication, interaction, or adhesion between cells
Plasmodesmata
DO NOT EXIST IN ANIMAL CELLS channels between adjacent plant cells (enable exchange between cells)
Gap Junction
DO NOT EXIST IN PLANT CELLS channels between adjacent animal cells (enable exchange between) cells
Tight Junction
DO NOT EXIST IN PLANT CELLS watertight (all fluid-tight) seal between two adjacent animal cells
Desmosome
DO NOT EXIST IN PLANT CELLS acts like a spot weld to ensure that cells in stretchy organs and tissues (e.g. skin, cardiac muscle) remained connected in unbroken sheets
Contrast plasmodesmata, tight junctions, desmosomes, and gap junctions
"Plasmodesmata are channels between adjacent plant cells (allowing for exchange between cells), while gap junctions are channels between adjacent animal cells (allowing transport of ions, water and other substances). A tight junction is a watertight seal between two adjacent animal cells, while a desmosome acts like a spot weld ensuring that cells in organs and tissues that stretch, such as skin and cardiac muscle, remain connected in an unbroken sheet."
69
69
Note 
Flashcard (38)