Test 2 ACTUALLY Flashcards
Magnification
Ration of an objects to its actual size
Resolution
Measure of an images clarity
Contrast
How different one structure looks from another in terms of brightness
Light microscope
Uses light from illumination. Was first invented in 1590
Electron microscope
Uses an electron beam for illumination
Transmission electron miscrscopy (TEM)
Beam of electrons transmitted through thin slide of the sample
scanning electron microscopy (SEM)
An electrons transmitted through thin slide of the sample
Cell fractionation
The breaking up of cell vía centrifugación,in order to allow scientist to better study sub cellular structures
Plasma (cell) membrane
Barrier surrounding each cell
Cytoplasm
Gel-filled region including everything inside the plasma membrane
Chromosomes
Tightly bound bundle of DNA, containing genes
Ribosomes
Non-organelles involved in protein synthesis
Nucleotide
Region where genetic material is likely to be found
Domain Bacteria
Abundant in everyday temperature environments
Domain Archea
Less common, found in extreme environmental conditions
Cell wall
Protective structure found outside the cell membrane in most prokaryotes and some protists, as well as in fungi and in plants. It helps to maintain the shape of cells and prevents excessive amounts of water from getting into the cell. It’s made of cellulose and is held together with pectin polysaccharides
Organelle
Membrane-bound compartment with its own unique structure and function within a cell
Nuclear envelope
Double membrane enclosing the nucleus
Nuclear pores
Providing passage ways for diffusion of small molecules
Nucleolus
Area is die the nucleus where the ribosomes are made. This region will be bigger in cells with active gene transcription
Endomembrane system
Network of varied membranes including nuclear envelope, the endoplasmic reticulum, the Golgi apparatus, lysosomes, vacuoles, and vesicles
Vesicles
Membrane enclosed sacs
Rough endoplasmic reticulum
studded with bound ribosomes and continuous with nuclear envelope and involved with protein synthesis and sorting but also capable of making phospholipids
Smooth endoplasmic reticulum
lack ribosomes and involved with the detoxification of drugs and poisons, carbohydrate metabolism, calcium ion balance maintenance, and synthesis and modification of lipids
Endoplasmic reticulum
Large network of membranes that form flattened, fluid-filled tubules or compartments used isn’t he manufacture of new molecules
Golgi apparatus
Center of cell product processing, sorting, and shipping. Cells are sent to the golgi through the ER and the cis side takes in the materials. Inside the cisternae the cell products and sent through the the trans side
Lysosomes
Organelles that contain acid hydrolase that performs hydrolysis and creates a space where cells can digest macromolecules safely
Phagocytosis
A type of endocytosis in which large particulate substances of smaller organisms are take up by the cell
Pinocytosis
A type of endocytosis in which a cell ingests extra cellular fluid and it’s dios solved solutes
Auotphagy
Lysosomes use their hydrolysis enzymes to recycle the cells own organic material
Food vacuoles
Formed by phagocytosis of materials in a cell environment, found in protist and human white blood cells and will eventually fused with lysosomes
Contractile vacuoles
Are found in freshwater protists and are used from expelling excess water
Large central vacuoles
Are found in plant cells for storage and cell support. Makes up most of the plant cell
Mitochondria
The primary role is to make ATP via cellular respiration but also involved in the synthesis, modification, and break down of several types of cellular molecules
Chloroplasts
Perform photosynthesis by capturing light energy and using it synthesize organic materials such as glucose
Peroxisomes
Organelles that generate and degrade hydrogen peroxide as part of detoxification reactions
Cytoskeleton
Network of Three different types of protein fibers found throughout the cytoplasm. the three main types of fibers are microtubules, intermediate filaments, and microfilaments
Microtubules
The largest fibers. long hollow cyndrical structures with dynamic instability. Involved in mitosis and meiosis. Cilia and flagella are both part of microtubules
Intermediate filaments
Mid-sized fibers. Rope like and religo ley stable. They reinforce cell shape and fix organelles to a specific location
Microfilaments
The smallest fiber. Long and thin fibers that have a dynamic cell stability( cell support and attachment) These are also referred to as actin filaments
Cilia
Often shorter than flagella and tend to cover all parts of sum part of the cell
Flagella
Usually longer cilia and are typically present in singles or pairs
What is similar between both cilia and flagella
They both have the same internal structure
Motor proteins
Category of cellular proteins that use ATP as a source of energy to promote movement. They have a head, hinge, and tail that they use to walk across the cell
Plasmodesmata
Cell wall channels that link the cytosol of neighboring plant cells, allowing material to pass between cells. this is only in plant cells
Tight junctions
Make a tissue watertight by providing connecting between close neighboring cells
Desmosomes
Keeps one cell attached to the other like buttons. They are not water tight and there are gaps in between like buttons
Which type of microscope gives scientists the highest level of magnification and resolution
SEM microscope
What is the difference between transmission electron microscopy and scanning electron microscopy
The scanning electron microscopy is the bets microscope because it is able to excite the the electrons to make a 3D image of the thing being looked at. The electron microscope cannot make a 3D image
During the process of cell fractionation, which “size class” of sub cellular structures will form pellets first
Larger sub cellular
Similarities and differences between Prokaryotes and Eukaryotes
Prokaryotic cells are very primitive and do not have a nucleus. Eukaryotic cells have membrane bound organelles while prokaryotic cells have organelles that float around in the cytoplasm
Main features of a Prokaryotic cell
No nucleus, no membrane bound organelles, small than Eukaryotic cells, has tail
How does the presence of organelles in. Ell sof eukaryotes always many of them to afford to be multicellular
More efficient use of time, energy, and cell materials due to division of labor
How does the presence of a plasma membrane ensure the maintenance of homeostasis on a cell
It decides what can come in and out of the cell at any time
What do the nuclear pores do
Allow materials such as mRNA and ribosomes to easily move from the nucleus into the endomembrane system
Where are ribosomes made
The nucleolus
How are vesicles used in the endomembrane system
They are used to package cell for intracellular transport or extra cellular export
What are the structural differences between the rough and smooth ER
The rough ER contains ribosomes as is involved in protein synthesis. The smooth ER does not contain ribosomes and involves the detoxification of drugs
What do lysosomes contain that help them break down a wide variety of substances
Acid hydrolase that performs hydrolysis
why are mitochondria and chloroplasts referred to as semi autonomous organelles
Because they are almost a small nucleus are thought to evolved from one cell eating another
What toxic by product do the demolition reactions occurring in a Peroxisomes create, and how does a Peroxisomes deal with this by product
The reactions create hydrogen peroxide, which is broken down by the Peroxisomes into water and oxygen gas thought the use of catalase
Be able to differentiate between descriptions cilia and flagella
Flagella is bigger than cilia and are only present by itself for with one other while cilia is smaller and mostly on larger groups
what are the three wats ATPcreate move to within a cell
By “walking” along a cytoskeleton fiber, by remaining stationary while cytoskeleton fiber is “pulled/fed along” beneath it, and by causing a cytoskeleton fiber to bend/flex
What are the three figures a plant cell has that an animal cell doesn’t
Large central vacuole, cell wall, chloroplasts
How are animal cells held in place
By ECM primarily composed by collagen fibers
Phospholipid bilayer
The composition of the plasma membrane studded with proteins
Amphipathic
Having both a hydrophilic and hydrophobic region
Selectively permeability
Some substances travel across it much more easily than others
Fluid mosaic model
Aggregate mosaic of lipid, protein, carbohydrate molecules resembling a fluid because the lipids and protein can move relative to each other with in the membrane
Peripheral proteins
non covalently bound to regions of integral proteins that project from the membrane, or bound to the polar head of phospholipids
Integral protein
Penetrate the hydrophobic core of the lipid bilayer
Glycolipid
Crabohydrate bound to a lipid
Glycoprotein
Carbohydrate bound to a protein, more common
Diffusion
The spontaneous tendency of any substance to spread out evenly across all available space
Concentration gradient
Difference in concentration
Passive transport
Does not require energy input and involves diffusion of a solute to achieve equal distribution on either side of the membrane barrier
Passive transport
Does not require energy input and involves diffusion of a solute to achieve equal distribution on either side of the membrane barrier
Passive diffusion
Does not require energy input and involves diffusion of a solute to achieve equal distribution on either side of the membrane bilayer
Facilitated diffusion
Diffusion of a solute through a membrane with the aid of a transport protein
Active transport
Requires an energy input and involves moving a solute moving “up its concentration gradient”
Osmosis
Diffusion of water across a selectively mergeable membrane
Hypertonic
Region with higher concentration of solute
Hypotonic
Region with lower concentration of solute
Turgor pressure
Water pressure present inside a plant cell that pushed the plasma membrane against that cell wall
Channel proteins
Form open passageways to allow the diffusion of ions or molecules across the membrane
Ion channels
Allow passage across membrane for ions, often gated
Aquaporins
Channels for water
Carrier proteins
Perform a conformational change to transport solute
homeostasis
living cells maintain a relatively constant internal environment different from their external environment
primary active transport
uses ATP as the energy source (as an ATP-driven pump) to transport solute
secondary active transport:
uses a pre existing concentration gradient to drive transport of solute
sodium-potassium pump:
actively transport Na+ and K+ against their gradients by using the energy from ATP hydrolysis (breakdown)
uniporter
single molecule or ion is moved
cotransporter (symporter
two or more ions or molecules are transported in the same direction
antiporter
two or more ions or molecules are transported in opposite directions
exocytosis
cell products are packaged into vesicles for export and excreted/released into the extracellular environment
phagocytosis
“cellular eating” of whole pieces of debris or arts of other cells
pinocytosis
“cellular drinking” of fluid
receptor-mediated endocytosis:
involves the entry of large particles that require recognition by a cell membrane receptor
signal transduction pathway:
process by which a chemical signal on a cells surface is converted into a specific cellular response
reception stage:
occurs when a signal molecule binds to a cellular protein
transduction stage
after binding with a signal molecule, a change occurs in the receptor protein that triggers a signal transduction pathway within a cell
response stage:
the transducer signal triggers specific cellular activities
paracrine signaling:
involves local chemical signals secreted by one cell and received by neighboring cels
synaptic signaling:
involves local chemical signals produces by one nerve cell and received by another nerve cell
hormones
involves long-distance chemical signal produced but the endocrine system
G protein-coupled receptors:
G protein-coupled receptors:
phosphorylation/dephosphorylation:
the transfer/removal of phosphate groups from ATP to proteins
protein kinases
enzymes that add phosphate groups from proteins
protein phosphatases:
enzymes that remove phosphate groups to proteins
wha is the major component of any biological membrane
phospholipid
which part of a phospholipid faces outward towards the watery environment
head
what produces energy for flippase to move lipids from one side of a membrane bilayer to the other
ATP
Will a membrane be more fluid if the fatty acid tails of its lipids are longer or shorter? Will a membrane be more fluid if single bonds or multiple bonds are present in the fatty acid tails of its lipids?
The shorter the fatty acid the more fluid it will be because the fatty acids will interact with each other less. The more the tails, the harder it is as well to interact, which makes the bilayer more fluid
What does cholesterol do for a cell
insulate a cell from extreme temps
how do the hydrophilic and hydrophobic regions of proteins determine how they can interact with cell membranes
The peripheral proteins bound to the polar header of the phospholipids while the integral proteins penetrate the hydrophobic core of the lipid bilayer
How is the movement of some membrane proteins restricted?
Cholesterol reduces membrane fluidity
When looking at a TEM image of a cell membrane cross-section, why do the hydrophobic centers of lipid bilayers look “empty,” while their hydrophilic “edges” appear dark?
The dye binds tightly with the polar heads but doesn’t effect the tails at all
Where are the lipids needed for cell membranes synthesized in a cell?
(smooth ER)
Where are the proteins needed for cell membranes synthesized?
(rough ER)
What properties make it more likely that a molecule will move easily across a membrane? What properties make it less likely to be able to move across?
Small, uncharges, or inside some sort of vesicle make it easies for molecules
Why do the processes of diffusion and osmosis occur?
Remember that the Second Law of Thermodynamics dictates that all substances tend to spread out evenly in a given environment because the universe tends toward entropy/chaos.
Why are plant cells not able to lyse? What does turgor pressure provide for a plant?
Turgor pressure is pressure that is always against a plant cell wall that keeps it from lysing (exploding)
Why do ions and water molecules require a protein channel to move across a membrane?
Ions are charged, which makes it harder for them to cross the membrane
What makes carrier proteins different from channel proteins?
Carriers are shape specific to let specific molecules across the membrane. Channels are just holes in the membrane that allow for things to pass through
Why is it important to control movement of molecules across a membrane?
Homeostasis cannot be kept if there are too little or too much of certain things
What is the difference between primary and secondary active transport?
Uses ATP to transport solute. Uses concentration gradient to transport solute
How does the sodium-potassium pump provide a good example of a primary transport antiporter?
It is an ATP-driven pump moving 2 substances in opposite directions.
Why is it also an electrogenic pump?
(It is moving positively charged ions in unequal numbers to opposite sides of a cell membrane.)
When very large molecules/particles/droplets are moved across a membrane via exocytosis or endocytosis, what “encapsulates” the material being moved?
Vesicles
Understand that the sequence of the three stages of a signal transduction pathway would be:
Reception stage where a ligand binds to a cellular protein, then transduction that occurs after the ligand has bonded that triggers a transduction pathway within a cell, lastly the response stage when the signal triggers specific cellular activities
Which of the types of signaling that we discussed (direct cell contact, paracrine signaling, synaptic signaling, or hormone signaling) is the only one that would work across long distances in a multicellular organism?
Hormones
Be able to recognize written descriptions of examples of cell membrane receptors (i.e. G protein-coupled receptors, tyrosine-kinase receptors, or ligand-gated ion channels embedded in outer cell membranes that are binding incoming chemical signals) vs. intracellular receptors (steroid or thyroid hormones that diffuse through cell membrane and then bind to receptors in the cytosol or nucleus).
The G- protein is like an on off switch for signaling molecules. When its bound to GDP its inactive and when its bound to GTP its active. The tyrosesn kinase receptor transfers phosphate groups from ATP to multiple tyrosine amine acids in order to allow their binding with more than one relay protein. Ligand gated ions is an ion channel guarded by ligands. Steroid and thyroid hormone signaling is hydrophobic chemical signals that pass through the cell membrane before being bound by cytosol to nucleus receptors
Why is the use of signal transduction pathways so beneficial to cells?
It produces an amplification of any incoming signals, and also allows cells to have a large degree of specificity and control over how they respond to a chemical signal.
What do glycolipids and glycoproteins do for the cell
often help receive signals or serve as markers on the surface of cells to provide a recognition flag for other cells to see
Land and cell membrane binding is…
ALWAYS SHAPE SPECIFIC
what is a common way to activate/deactivate relay proteins that are involved in a signal transduction pathway
phosphorylation/dephosphorylation
different type of cells receiving identical incoming cells are likely to…
have completely different responses due to variation that exists in their individual signal transduction pathways
Homeostasis
Living cells maintain a relatively constant internal environment different from their external environment
