ap bio- chapter 6&7
Water moves into a cell when the solution surrounding the cell ...
is hypotonic in comparison to the cell
why are cells small?
keep the ratio of surface area to volume reasonable so material can enter in reasonable time
central vacuole
keep water in cell
extracellular matrix
like a cell wall for animals, glycoproteins
glycolipid
lipid bound to carb
peripheral proteins
loosely bound to the surface of the membrane (does not go in bilayer), nut & bolt
What happens in the nucleolus
make rRNA (for cell replication)
organelles in endomembrane system
nuclear envelope, smooth/rough ER, golgi body, vesicles, lysosomes, vacuoles, plasma membrane
integral proteins
penetrate the hydrophobic interior of lipid bilayer, amphipathic
food vacuole
phagocytosis then fuse with lysosome
what organisms have cell walls?
plants, fungi, unicellular eukaryotes
where is DNA in each type of cell
prokaryote- unbound region (nucleoid) eukaryote- bound region (nucleus)
glycoprotein
protein bound to carb
facilitated diffusion/passive transport
protein helps move molecules/ions through lipid bilayer without energy (high concentration to low concentration)
functions of rough er
protein synthesis, found in large quantities in muscle cells
contractile vacuole
pump water out of cell (freshwater plants)
The interior of the lipid bilayer of a cell membrane forms a nonpolar zone that
repels ions and most polar molecules.
The picture shows a cell model and the solutions associated with it. In this situation the cell model will- (cell is 98% water & solution is 95% WATER)
shrink
Which phrase best describes the property of selective permeability of the lipid bilayer of the plasma (cell) membrane?
small uncharged molecules can pass through
How does water pass through the cell membrane?
through aquaporins, which are channel proteins just for water
cell junctions
tight- plasma membranes seal w each other desmosomes- attach muscles gap- attach cytoplasm to cytoplasm
functions of membrane proteins
transport, enzymic activity, cell recognition, transduction, intercellular joining, attach to cytoskeleton, extracellular matrix
exocytosis
vesicle fuses with membrane to release contents
motor proteins
walk along the cytoskeleton, use ATP
Which of the following statements about the model cell with a water potential of -1 bars in a sucrose solution with a -3.5 bars as shown below is FALSE?
Water will move from the beaker to the model cell.
In the diagram below, the dark dots indicate small molecules. These molecules are moving out of the cells, as indicated by the arrows. The number of dots inside and outside of the two cells represents the relative concentrations of the molecules inside and outside of the cells. ATP is being used to move the molecules out of which cell? A is going from low to high concentration, B is going from high to low concentration
cell A, only
cytoskeleton
A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement
A cell with 5% solute concentration is placed in a beaker with a 1% solute concentration. What will happen to the cell over time?
Cell will expand as it gains water
plasmolysis
Collapse of a walled cell's cytoplasm due to a lack of water
peroxisosomes
Removes H2 O2
Jennifer is observing a cell in a calcium ion (Ca2+) solution and calculates that the concentration of calcium ions in the cell is 100 nM and 2 nM outside the cell. If channel proteins in the cell membrane allow calcium ions to pass from one side to the other, in which direction will these ions naturally flow without an input of energy?
The calcium ions will flow out of the cell.
phagocytosis
cell absorbs bacteria (through endocytosis)
endocytosis
cell takes in material by engulfing it with the membrane
pinocytosis
cells absorbs liquid (through endocytosis)
aquaporin
channel protein for water
plasmodesmata
channels through cell walls that connect the cytoplasms of adjacent cells
Which of the following components of plasma membranes is a steroid that prevents the membrane from becoming either too fluid or too rigid?
cholesterol
The difference in the concentration of dissolved particles from one location to another is called a
concentration gradient
chromosomes/chromatin
condensed DNA/DNA with proteins that help it maintain shape
function of smooth er
detoxification, found in large quantities in liver cells
The dispersal of ink in a beaker of water is an example of
diffusion
active transport
energy (ATP) is required, low concentration to high concentration
The diagram below shows how glucose molecules move down a concentration gradient to enter a cell with the help of transport proteins. What type of transport is being shown?
facilitated diffusion
Transport proteins play a role in both
facilitated diffusion and active transport.
The movement of molecules down a concentration gradient through transport proteins in the cell membrane is a type of
facilitated diffusion.
amphipathic
had both a hydrophobic & hydrophilic region
phospholipid
hydrophilic head (phosphate group), 2 fatty acid tails (hydrophobic), amphipathic
Calculate the water potential of a 0.8M sucrose solution in an open container at 25°C.
-19.8 bars
The approximate molarity of the solution in which the mass of the plant pieces would not change is
.3 M
At 25°C, a cell with a ψP of 3 bars is in equilibrium with its surrounding solution containing 0.2M sucrose in an open container. What is the cell's solute concentration? (i = 1)
0.32 M
Jonah was rushed to the hospital after a bad car accident. He has a cut on his leg that is bleeding very heavily. The doctor orders an IV of saline solution that consists of water and 0.9g/L of sodium chloride, which closely matches the sodium chloride concentration in blood. What type of solution is the saline in the IV to the blood cell?
Isotonic
Which of the statements about the 0.6 M sucrose solution is TRUE? (based off graph: -17% change in mass)
It is hypertonic in comparison to the plant cells
Refer to this experiment in which a dialysis-tubing bag is filled with a mixture of 3% starch and 3% glucose and placed in a beaker of distilled water, as shown below. After 3 hours, glucose can be detected in the water outside the dialysis-tubing bag, but starch cannot. Which of the following statements are true?
The dialysis tubing is impermeable to starch
If a plant cell is placed in an environment that is hypotonic in comparison to itself, what do you think will happen to the pressure potential (Ψp) within the plant cell?
The pressure potential will increase as water flows into the cell causing the membrane to press against the cell wall.
Refer to this experiment in which a dialysis-tubing bag is filled with a mixture of 3% starch and 3% glucose and placed in a beaker of distilled water, as shown below. After 3 hours, glucose can be detected in the water outside the dialysis-tubing bag, but starch cannot. What will be the condition in 24 hours?
The solution in the dialysis-tubing bag will contain a greater percentage of water than it did 24 hrs ago.
nuclear matrix
a framework of protein fibers extending throughout the nuclear interior
Which of the following factors would tend to increase membrane fluidity?
a greater proportion of unsaturated phospholipids
For a protein to be an integral membrane protein, it would have to be ____.
amphipathic, with at least one hydrophobic region