Exam 2- Cells Flashcards
The most common gradients are the result of concentration differences, therefore called
Concentration gradients
Molecules move naturally with gradients from areas of high to low concentration, and it requires no energy
Passive transport
Molecules can also be moved against gradients from areas of low to high concentration, it requires energy
Active transport
How do some molecules move passively into cells? Moves with concentration gradient and it’s small enough to pass through the bilayer molecules. Example: food coloring in water
Simple diffusion
Specific type of diffusion that involves water is called
Osmosis
Ability of a surrounding solution to cause a cell to gain or lose water
Tonicity
Equal movement of water in and out of cells
Isotonic
Water goes into the cell and expands.
Hypotonic
Water goes out of the cell and shrinks
Hypertonic
A plant cell undergoes
Plasmolysis
Changes in cell shape can alter its ability to function, cells may have certain mechanisms in place in an attempt to maintain a proper water balance, also known as
Osmoregulation
Microorganisms pump water out to prevent lysis by osmotic water diffusion into the cell
Contractile vacuoles
Water content in the large central vacuole of plants help provide ___ on the cell walls
Turgor pressure
Loss of this pressure can cause wilting where the cells can become
Flaccid
The membrane is considered differentially or selectively permeable because
Membrane proteins can allow passage of certain select substances through the bilayer
Facilitated diffusion
Passive transport aided by protein transporters
Proteins act as pumps to transport materials as an example of
Sodium-potassium pump
In some cases, active transport of one substance can be used to establish a
concentration gradient in order to power the transport of a second substance
Cotransport
One carrier builds a high concentration of a substance on one side of the membrane, the substance then moves back via facilitated diffusion through a ___ bringing along another substance
Symporter
If a substance is moved in the opposite direction of its partner, the carrier is called an
Antiporter
A region of the plasma membrane surrounds the material and pinches it off into a vesicle inside the cell
Endocytosis
Large particles are surrounded and engulfed is called
Phagocytosis
The extracellular fluid is surrounded and internalized is called
Pinocytosis
Materials first bind to outer receptors is called
Receptor-mediated
The particular biomolecule a receptor protein binds to is called
Ligand
The reverse process, secreted materials are released from the cell in this way is called
Exocytosis
A combination of endo and exocytosis
Transcytosis
Microtubules
The largest, composed of protein tubulin
Microtubule organizing center
Plant cells can have many, but fungi and animals have one
- In animals it is known as the centrosome
Kinesin
Protein motor protein
Cilia
Like haired structures
Primary cilium
Involved in signal reception
Flagella
Same as cilia but longer.
Axoneme
9+2 core structure of microtubules
Basal body
9+0 arrangement
Dynein
Links the multiple microtubule components of cilia together
Microfilaments
Thinnest of the cytoskeletal components, they are composed of thin rods called actin
Thin rods called
Actin
Cytoplasmic streaming
Where cytosol is made to circulate throughout the cell
Intermediary filaments
Are sized in between the other two filaments.
Cellulose synthase
The cellulose is synthesized by enzymes in the plasma membrane
Hemicellulose
Another polymer of glucose
Pectin
A gel that fills the space between cellulose fibers
Plant cells
Possess a single primary cell wall
The space in between primary cell walls of adjacent cells is called the
Middle lamella
Disrupt hydrogen bonds between celluloses so they can slide past each other and the wall can expand is called
Expansins
Cells that are no longer expanding can deposit a
Secondary cell wall
Lignin
Waterproofs the secondary wall, is hydrophobic
Extracellular Matrix
Animal cells have ECM and are composed of collagen
The collagen fibers are also bound to proteins in the ECM called
Fibronectins
The fibronectin in turn, is connected to the cell surface by transmembrane proteins called
Integrins
Protein strands that extend into and out of the cell
- the internal portion anchors to intermediate filaments
Desmosomes
Proteins called _________ extend outward and interact with each other
Cadherins, holds adjacent cells together like Velcro.
Tight junctions
Proteins that fuse together between the cell membrane, prevents leakage
Gap junctions
Channels that connect insides of cells, similar to air ducts
Plasmodesmata
Continuation of plasma membrane in adjacent cells, the plasma membrane is shared between cells
How can the cell membrane transmit information from outside the cell to the
inside?
Signal transduction
Proteins embedded in the membrane called
Signal Receptors
They are called _ proteins because they bind GTP
G
The product produced as a result of this enzyme being turned on acts as a
Secondary Messenger
Activation of an enzyme called
Adenyly cyclase
These messengers often activate
Protein kinases
Cells are the smallest unit of life
True!
the Cell Theory states three principles about cells, what are they?
a) all living things are made up of cells
b) a cell is the smallest unit of living things
c) all cells arise from pre-existing cells
Cells are so small because
The have to get materials through the surfaces
All cells share three main features, what are they?
a) they are surrounded by a plasma membrane (discussed previously)
b) they contain cytoplasm, the aqueous environment inside a cell
- the cytoplasm contains organelles; structures that can perform
specific cellular tasks
- most are membrane-bound, but not all
- the jelly-like fluid alone is referred to as cytosol
c) they contain DNA in the form of chromosomes
Prokaryotic the DNA is called ___ and have ___
Nucleoid, and ribosomes
Bacterial cell walls are made up of _____
Peptidoglycan
Eukaryotic cells are composed of ____ or ____
Cellulose, or chitin
Nucleus
the control center
Importins
Protein that carries in the materials in the cell
Exportins
Protein that takes the materials out of the cell
What is the Rough ER?
Presence of bound ribosomes gives the surface a textured appearance
What is the Smooth ER?
Site of membrane lipid synthesis, also gives presence have bound ribosomes gives the surface a smooth appearance.
Transport vesicle (like a bubble made up of membrane)
90% of the time will go to the Golgi
Golgi Apparatus
A series of flattened membrane sacs stacked together
Cisternae
The walls of the Golgi
CIsface
The receiving side of the Golgi
Transface
The transferring side where it pinches off the protein out and into a cell
Golgi will do an attachment of a _____ ____ and it acts like a zip code.
Carbohydrate tags
SRP
Signal Recognition Particle
Are bound ribosomes and free bound ribosomes the same?
Yes, the only difference is the location.
The ER is?
An interconnected network of membrane based tunnels.
Lysosomes
Breaks down the larger biomolecules
Peroxisomes
Protective Role against R.O.S (reactive oxygen species)
Glyoxysomes
Breaks down photosynthesis byproducts.
Vacuoles
Storage compartments, in plant cells there only one large vacuole and in animal cells there are multiple ones involving storage.
Plant cells have one big vacuole, it maintains what?
Turgor pressure
Mitochondria
Site of aerobic (requires oxygen gas) cellular respiration
What does the Mitochondria have?
It’s own DNA + ribosomes.
The folds, inner wall, and outer wall of the Mitochondria is called what?
Cristae, folds, and inter-membrane compartment
Plastids
Site of the photosynthesis
The membrane, inner space, and the inside stuff of the Plastid is what?
Thylakoid membrane, Stoma, and Lumen.
Amyloplast
Stores starch
Elaioplast
Stores oil
Chromoplasts
Producing pigment, food and or storing pigment and food.
