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