Unit 2 - Cell Structure and Function Flashcards
higher solute concentration
hypertonic
lower solute concentration
hypotonic
equal solute/solvent concentration
isotonic
diffusion of free water across a selectively permeable membrane
osmosis
the total solute concentration in a solution
osmolarity
Water moves by osmosis into the area with a _______ _______ concentration.
HIGHER solute
Water concentrations and solute concentrations are _______ related
inversely
Water would diffuse out of a ________ environ. –> _______ environ.
hypotonic, hypertonic
Solutes diffuse along their own concentration gradients, __________ environ. –>_________ environ.
hypertonic, hypotonic
In plant and animal cells, osmoregulation maintains ______ balance and allows _______ of internal solute composition/water ________
water, control, potential
LESS cellular solute and MORE cellular water
environmental hypertonicity
EQUAL solute and water
isotonic solution
MORE cellular solute and LESS cellular water
environmental hypotonicity
What is a plant cell’s state in environmental hypertonicty?
Plasmolysis
the process in which cells lose water in a hypertonic solution
plasmolysis
What is a plant cell’s state in isotonic solution?
flaccid
cell lacking turgidity
flaccid
What is a plant cell’s state in environmental hypotonicity?
turgid
OPTIMUM STATE FOR PLANT CELLS
turgidity
Water flows into the plant vacuoles via ________ causing vacuoles to _______ and press against the cell wall
The cell wall expands until it begins to exert the pressure back on the cell, this pressure is called ____________ __________
osmosis, expand, turgor pressure
______ _____ maintains homeostasis for plant in environmental hypotonicity
Cell wall
What is an animal cell’s state in environmental hypertonicty?
shriveled
What is an animal cell’s state in isotonic solution?
normal
What is a animal cell’s state in environmental hypotonicity?
lysed
External environments can be _________, ________, or ________ to the internal environment of cells.
hypertonic, hypotonic, isotonic
Water moves by OSMOSIS from areas of ______ osmolarity/solute concentration to areas of ______ osmolarity/solute concentration.
LOW, HIGH
Growth and homeostasis are maintained by the _________ movement of molecules _______ membranes.
constant, across
Osmoregulation maintains ________ balance and allows organisms to control their _______ _______ compostion
water, internal solute
measures tendency of water to move by osmosis
Water potential
Water potential is calculated from __________ potential and _________ potential
pressure, solute
Water moves by ________ from an area of ________ water potential –> _____ water potential
osmosis, HIGH, LOW
Water moves by ________ from an area of ________ solute potential –> _____ solute potential
osmosis, HIGH, LOW
Values of water potential can be ________, _________, or _________
positive, negative, zero
The more _______ water potential is, the ______ likely it is to move into an area
negative, more
Osmoregulation allows organisms to control what 2 things?
internal solute composition, water potential
As solute potential increases, water potential ___________.
descreases
As pressure potential increases, water potential ___________.
increases
As pressure potential decreases, water potential ___________.
decreases
In an ________ system the pressure potential is ZERO –> water potential ______ solute potential
OPEN, equals
Small molecules pass ______ across a cell membrane
freely
What are three examples of small molecules that can pass across a membrane?
N2, O2, CO2
movement of molecules from high concentration to low concentration
diffusion
Small amounts of very ______ molecules, like water, can diffuse across a cell membrane
polar
movement of molecules from high concentration to low concentration through TRANSPORT PROTEINS
facilitated diffusion
the diffusion of water across a selectively permeable membrane
osmosis
Large quantities of water move via ____________.
aquaporins
Differences in relative solute concentrations can facilitate _________
osmosis
net movement of molecules down their concentration gradient
passive transport
the movement of molecules against their concentration gradient
active transport
Active transport moves molecules and or ions against their concentration gradient from _____ concentration to _____ concentration
LOW, HIGH
carrier proteins used in active transport
protein pumps
Active transport requires _________ energy (such as ATP).
metabolic
Active transport establishes and maintains ___________ __________.
concentration gradients
Name the process:
The cell uses energy to take in macromolecules and particulate matter by forming new vesicles derived from the plasma membrane
endocytosis
Name the process
The cell’s internal vesicles use energy to fuse with the plasma membrane and secrete large macromolecules out of the cell
exocytosis
What are the three types of endocytosis?
Phagocytosis, pinocytosis, receptor-mediated endocytosis
_________ ________ is the net movement of molecules from high concentration to low concentration without direct input of metabolic energy.
Passive transport
Via simple diffusion, water is transported in ____ amounts
small
Via facilitated diffusion, water is transported in ________ amounts through _________
large, aquaporins
______ ________ requires the direct input of energy to move molecules from regions of low concentration to regions of high concentration.
active transport
Large molecules and large molecules are moved INTO the cell by ________.
endocytosis
Large molecules and large molecules are moved OUT OF the cell by ________.
exocytosis
Phospholipids are _____________.
amphipathic
Phospholipids have a _________ ________ head and _______ ___________ tail.
polar hydrophillic, nonpolar hydrophobic
Phospholipids spontaneously forms a ______ in an AQUEOUS environment
bi-layer
Selective permeability is a direct consequence of ________ ______
membrane structure
What are the two types of transport proteins?
channel and carrier
What type of transport protein spans membrane and changes shape to bring molec. into cell?
carrier
What type of transport protein is a hydrophilic tunnel that allows small molecules to move through?
channel
What cell organelle:
- is the boundary between cell and environment
- controls transport of materials in and out cell
cell membrane
What are the two types of embedded protein?
peripheral and integral
Embedded proteins can be _______ or ________.
hydrophilic or hydrophobic
an embedded protein that is loosely bound to the exterior of the cell membrane
peripheral protein
A peripheral protein is HYROPHILIC with ______ ______ _______ groups
charged polar side
A peripheral protein is HYDROPHILIC with ______ ______ _______ groups
charged polar side
an embedded protein that spans the cell membrane
integral protein
A peripheral protein is:
- HYDROPHILIC with ______ ______ _______ groups
- HYDROPHOBIC with ______ side groups
and:
__________ hydrophobic interior of bilayer
charge polar side, nonpolar, penetrates
The structure of the cell membrane is called a ________ _______. It is not _______ because it is joined by _________ interactions, which are weaker than covalent bonds.
fluid bilayer, static, hydrophobic
A steroid type found between phospholipid layer and cell surface
cholestrol
regulates bilayer fluidity under different conditions
cholesterol
Diversity and loca. of carbs and lipids enable them to function as _____________.
markers
What are the six functions of embedded proteins?
(1) Transport
(2) Cell-cell recog.
(3) Enzymatic activity
(4) Signal transduction
(5) Intercellular joining
(6) Attachment for extracellular matrix or cytoskeleton
A protein that forms an ion channel through a membrane is most likely
a transmembrane protein
_______ function as recognition sites for interactions between cells
glycolipids
______________ is the driving force for BOTH facilitated and simple diffusion.
Concentration gradient
a passive process during which molecules move from a region of higher to lower concentration
Diffusion
What is the cholesterol in the cell membrane?
It stabilizes the cell membrane
composed of ribosomal RNA and protein. They help to synthesize proteins.
ribosomes
provides mechanical support and plays a role in intracellular transport 🚕
endoplasmic reticulum (ER)
What are the two types of ER?
Rough and smooth
helps to compartmentalize the cell and helps to carry out protein synthesis in the ribosomes.
Rough ER
helps in detoxification and lipid production
Smooth ER
- a membrane-bound organelle that is composed of several flattened membrane sacs
- vital in the final stages of preparing a protein. - helps correctly folding and modifying protein as needed
- packages 📦 proteins
Golgi Complex
- helps with ATP production
- has a small set of its own DNA 🧬
- a double membrane organelle
- its outer membrane is a smooth phospholipid bilayer
- its inner membrane is highly convoluted, (highly folded) which increases the surface area for a growing number of electron transport chains
Mitochondria
The mitochondria’s increase in _____ ________ facilitates the production of ATP.
surface area
Where does cellular respiration occur?
mitochondria
What is the first step of cellular respiration?
It occurs with or without _____.
It does NOT occur in the ______.
glycolysis; oxygen; mitochondria
After the completion of glycolysis, the rest of cellular respiration occurs in the ___________, given that __________ is present.
mitochondria; oxygen
Where does the Citric Acid/Krebs Cycle occur?
matrix of mitochondria
Oxidative phosphorylation, with the help of the electron transport chain, occurs in the _______ ________.
inner membrane (of mitochondria)
- membrane-enclosed sacs that contain hydrolytic enzymes
- these enzymes = digestive enzymes –> help to break down 🚮 excess or worn-out cell parts
- help with programmed cell death ☠️, apoptosis
lysosomes
- a membrane-bound sac that has many different roles including:
storage + release of macromolecules and waste
vacuole
Plants 🌱 have a specialized large central vacuole that also serves many functions. The primary function of the large central vacuole is ____ ______.
water retention
Water retention is important for _____ ______.
turgor pressure
- photosynthetic algae and plants contain specialized organelles that can photosynthesize (capture, store, and use solar energy ⚡️) and make simple sugars
- have double membrane and thylakoids = flattened sacs with a phospholipid bilayer.
chloroplasts
Plants cells have BOTH chloroplasts AND _________
mitochondria
Where does photosynthesis occur?
chloroplast
What are the two stages of photosynthesis?
light-dependent ☀️ and light-independent 🌓
The light-DEPENDENT reaction of photosynthesis occurs in the _______ and produces the _____ and ______ necessary for the light-independent reaction.
grana; ATP, NADPH
The light-INDEPENDENT reaction of photosynthesis is where the _______ ______ takes place and ______ is fixed to make simple ______.
Calvin-Benson, carbon, sugars
In what type of microscopy are animal cells visible?
light
type of electron microscopy - slices through nucleus with a diamond blade
transmission
type of electron microscopy - scans electrons on surface of cell and produces 3D image of organelles
scanning
What is the only thing that can leave the nucleus?
RNA
Animal cells have multiple mito_______.
Plant cells have multiple chloro_______ and mito_________.
chondria; plasts, chondria
What is the biggest organelle in the plant cell?
central vacuole
Eukaryotic vs Prokaryotic:
- DNA
- Ribosomes
- Golgi and ER?
Eukaryotic | Prokaryotic
- contained in membrane | - free
- regular | - smaller 70s rib.
- yes | - no
Free living prokaryotic cells ate by primitive pro-eukaryotic cells to become mitochondria and chloroplasts seperately
endosymbiotic theory
a membrane bound sac
vesicles
What is the shape of vesicles, including vacuoles, contractile vacuoles, lysosomes, and peroxisomes?
circle
large vesicle, function varies; found in animal and plant cells
vacuoles
found in protists and other things; helps regulate temperature in paramecium
contractile vacuole
vesicle with enzymes that remove H+ found in plants and animals
peroxisomes
What human organs should have a higher amount of peroxisomes?
- Liver
- Kidney
- Lungs
Both chloroplasts and mitochondria have their own ______.
DNA
type of phospholipid in phospholipid bilayer/cell membrane:
- one or more double bonds create a “kink” or bend that pushes phospholipids in cell membrane apart and make more liquidy
unsaturated
Kinks make the cell _______.
weaker
The more compact your membrane is, the more ______ it is.
sturdy
type of phospholipid in phospolipid bilayer/cell membrane:
- normal and no kinks
saturated
Low temperatures cause phospholipids to draw closer to each other. Cholesterol pushes the phospholipids _______ from each other.
away
Higer temperatures cause phospholipids to drift farther from each other. Cholesterol pushes the phosphlipids ________ to each other.
close
What does cholesterol do for the cell membrane?
Stabilizes it
At low temperatures, cholesterol prevents the membrane from ______.
hardening
At high temperatures, cholesterol keeps membrane _______.
solid
_______, ________ molecules can pass through the cell membrane through simple diffusion
small, hydrophobic (non-polar)
channel proteins that only allow water in (passive transport)
aquaporin
not really an organelle - a clump of DNA that produces ribosomes
nucleolus
The inside of a transport protein is likely to be ________.
hydrophillic
Protein CHANNELS allow ______, ______ molecules or polar molecules to cross the plasma membrane. __________ amino acids will line the inner portion of the channel to allow this movement.
small, charged, hydrophillic
What three organelles display folded structures which allows them to function more efficiently?
The Golgi complex, mitochondria, chloroplast, and endoplasmic reticulum (ER)
Prokarya do not have ____________ or __________.
mitochondira, chloroplasts
Facilitated diffusion is an example of _________ transport. The movement of water across a cell membrane _______ require energy but it is facilitated or helped through _______ membrane proteins.
passive, doesn’t, aquaporin
A mutation causes the membrane of a lysosome to become leaky. Describe a result of this:
Hydrolytic enzymes leak into the cytoplasm causing digestion of vital proteins.
The lysosomal membrane separates __________ enzymes from the _______. Without this membrane, hydrolytic enzymes are capable of __________ essential components in the cytosol.
hydrolytic, cystol, destroying
This organelle contains a double membrane which provides compartmentalization to separate different metabolic reactions
mitochondria
The water potential of pure water is:
0
PURE water DOES NOT contain any _______. As solutes are added to a solution, water potential becomes MORE ______.
solute, negative
epidermal pores on a plant’s surface that are essential for the control of water balance in plants
stomata
- located in the leaf epidermis
- form stomatal pores, which regulate CO2 influx from the atmosphere into the leaves for photosynthetic carbon fixation
- regulate water loss of plants via transpiration to the atmosphere by closing/opening stomata
guard cells
Osmoregulation in plants occurs by
the work of guard cells
the process of regulating water potential in order to keep fluid and electrolyte balance within a cell or organism relative to the surrounding
osmoregulation
The membrane of the chloroplast is _______ permeable.
FREELY
stacks of thylakoids
grana
the site of photochemical or LIGHT-DEPENDENT reactions of photosynthesis
thylakoid
Increased folding increases efficiency for________ __________ reactions, and all reactions in the chloroplast.
light-dependent
Fluid between the inner chloroplast membrane and outside thylakoids
CARBON FIXATION (CALVIN CYCLE) REACTIONS OCCUR HERE
stroma
________ captures energy from macromolecules.
Mitochondria
Some viral infections can lead to the rupture of the lysosome membrane. Which prediction of the effect of this disruption of cellular compartmentalization is most likely correct?
Hydrolytic enzymes will be released, which will cause cell death.
Gaucher disease is an inherited disorder in which cells of the body are unable to break down a particular type of lipid, resulting in a buildup of the lipid in some tissues and organs.
Based on the information provided, Gaucher disease results most directly from a defect in the function of which of the following organelles?
The lysosome
The _________ contains specific enzymes used to break down a variety of molecules and cellular waste products.
lysosome
Testosterone is a small steroid hormone that is important in cell signaling. Which of the following describes where testosterone enters a cell and why it is able to cross at that point?
testosterone is nonpolar and can diffuse through the membrane.
Researchers investigate the transport of a certain protein into cells by endocytosis. In an experiment, the researchers incubate the cells in the presence of the protein and measure the amount of the protein that is absorbed into the cells over a five-minute period.
Based on their observations, what should the researchers do to further clarify how the availability of the protein outside the cells affects the rate of endocytosis of the protein?
Incubate the cells in the presence of several different concentrations of the protein.
Which of the following transport mechanisms will be affected most directly by a temporary shortage of ATP molecules inside the cell?
The transport of glucose molecules against a concentration gradient
Photosynthesis is a process used by both _________ and some _________.
eukaryotes (algae and plants), prokaryotes (cyanobacteria)
Which of the following observations best supports the claim that mitochondria evolved from once-free-living prokaryotic cells by the process of endocytosis?
Mitochondria has a double membrane
The double membranes of mitochondria provide evidence that an ancestor of mitochondria, which was most likely a type of free-living ______ ________, was ingested via endocystosis by a ________ eukaryotic cell.
aerobic bacterium, primitive
Beetroot cells contain a family of dark red pigments called betalains. The selectively permeable nature of the beetroot cells keeps the internal environment of the cell separate from the external environment of the cell. Researchers are interested in determining whether the selective permeability of beetroot cells is due to the cell membrane or if it is due to the cell wall.
Exposure to cellulase is known to damage the structure of the cell wall. An experiment is set up in which beetroot cells are placed in an aqueous solution with cellulase and in one without cellulase.
Which of the following results best refutes the alternative hypothesis that selective permeability is a consequence of the cell wall?
When beetroot cells are placed in a solution with cellulase, the solution remains clear.
Cellulase digests _______ and damages the structure of the cell _____, not the cell ________. The lack of color change in the solution indicates that the betalain is not leaking out of the beetroot cells even though the cell wall has been damaged. This refutes the alternative hypothesis.
cellulose, wall, membrane
Why do the hydrolytic enzymes released by lysosomes when they fuse with damaged organelles do not continue to act on other health functioning organelles are the targeted organelle is broken down and recycled?
Enzymes of lysosomes = acidic pH for functional shape
alkaline pH of cytosol quickly denatures them
A researcher studying membrane dynamics fuses two small cubiodal cells together to form one cell. What happens to the cell due to the altered SA:V?
The cell will have difficulty taking in and eliminating nutrients and waste materials.
The HYDROPHOBIC tails of the cell membrane phospholipid bilayer prevent large quantities of ______ from entering the cell without _______ _______.
water, transport proteins
The HYDROPHILLIC heads of the cell membrane phospholipid bilayer allow large quantities of ______ from entering the cell without _______ _______.
small, nonpolar molecules; transport proteins
Potassium ions (K+) will use ______ diffusion to travel ACROSS GRADIENT to the less concentrated, HYPOTONIC cell solution
facilitated
Potassium ions (K+) will use ______ _______ to travel AGAINST GRADIENT to the concentrated, HYPERTONIC cell solution
active transport
