Chp 5-7 Test

Question 1

what factors might affect membrane permeability

Answer 1

of unsaturated and saturated fatty acid tails
temperature: high temp may denature proteins making it more permeable or cool temp will cause the membrane to solidify (if the temperature changes slightly it will stay fluid because it has unsaturated fatty acid tails that do not let them pack too tight)
amount of proteins found in the membrane: larger amount then more molecules can move in and out
pH: may denature some of the proteins

Question 2

examples of passive transport

Answer 2

NO ENERGY: diffusion, osmosis, facilitated diffusion

Question 3

diffusion

Answer 3

tendency for molecules to spread out evenly in a defined space; random thermal movement (high to low concentration) EX: dropping food color into water NO ENERGY NEEDED

Question 4

osmosis

Answer 4

diffusion of water across a membrane structure EX: water entering a cell (high to low concentration) NO ENERGY NEEDED

Question 5

facilitated diffusion

Answer 5

need a transport channel protein with a pathway because the molecules are either small and polar or too large to fit through the membrane without the transport channel protein (high to low concentration) EX: aquaporins NO ENERGY NEEDED

Question 6

examples of active transport

Answer 6

NEED ENERGY (ATP): sodium/potassium pump, endocytosis, exocytosis

Question 7

sodium/potassium pump

Answer 7

pump sodium against the gradient and out of the cell and bring potassium into the cell. ATP phosphorylates the transport protein causing it to change its shape

Question 8

endocytosis

Answer 8

movement of molecules or liquids into the cell creating a vesicle using energy EX: a macrophage digesting a viral infected cell (two types, pino- and phagocytosis)

Question 9

exocytosis

Answer 9

taking a vessel that the golgi apparatus has made and the vessel merges with the cell’s plasma membrane to empties its contents outside the cell EX: signal molecules that the cell molecules that is releasing a hormone into the blood stream

Question 10

hypertonic

Answer 10

a solution that has higher solutes but lower water compared to whatever is in the solution. The cell will shrink and shrivel up.

Question 11

hypotonic

Answer 11

a solution that has lower solutes but higher water compared to whatever is in the solution. The cell will expand-do not worry if a plant cell, worry if animal bc no cell wall and might burst.

Question 12

isotonic

Answer 12

solute concentration in solution is equal to solute concentration in the cell. water concentration in solution is equal to the water concentration in the cell

Question 13

what happens when signal molecules bind to G-coupled protein

Answer 13

G-couples protein receptors are sitting in the membrane. A signal molecule has to bind to the protein receptor-specific for it, has the same shape. Causing the G-protein/GDP to be activated by receiving a phosphate and forming GTP. Then the G-protein travels along the inside of the membrane using microtubules and ATP. It then binds to an enzyme (Adenyl cylcase) that is also in the membrane and activate it by changing its shape. When the signal molecule detaches the enzyme deactivates and goes back to its original shape and the G-protein loses a phosphate and is inactive.

Question 14

what types of signal molecules pass easily through membranes

Answer 14

small molecules (O, CO2) or non polar molecules (steroids, estrogen). their receptors are in the cytoplasm

Question 15

yeast mating factors and how they work

Answer 15

Yeast a creates a signal molecule called alpha and the alpha yeast will create a signal molecule called a. They release them through exocytosis. The signal molecules of alpha will bond to the alpha yeast, the signal molecules of a will bond to the alpha a. When they bind they signal each other to come together. Their nuclei together.

Question 16

first messenger molecule

Answer 16

the original signal molecule. function: starts a signal transduction pathway

Question 17

second messenger molecule

Answer 17

nonprotein water soluble molecule that comes in later in the pathway to help push the signal along farther into the pathway. EX: cAMP

Question 18

cAMP

Answer 18

its a second messenger molecule and it pushes the signal farther into the pathway (cyclic AMP)

Question 19

purpose of phosphorylation cascades

Answer 19

the transduction part of the cascade using kinases to phosphorylate other molecules which continue the signal. possible cell responses: turning on/off a gene, stop/starting to make a protein, and tells cell to divide

Question 20

ATP-where is the energy stored in the molecule

Answer 20

in the bonds-the potential energy in the bonds of the phosphate

Question 21

enzymes

Answer 21

usually a protein, has an active site that was coded during the folding process (active site fits the substrate). creates an environment for the substrate reaction

Question 22

substrates

Answer 22

the molecule or molecules that fit into the enzymes active site. creating an induced fit and producing the product

Question 23

allosteric regulators

Answer 23

a molecule that binds to the enzyme at a different place than the active site resulting in its ability to regulate the availability of the inactive site-can inhibit or enhance

Question 24

exergonic reaction

Answer 24

spontaneous reaction, releases energy EX: ATP

Question 25

endergonic reaction

Answer 25

non spontaneous reaction, absorbs energy EX: photosynthesis

Question 26

anabolic reaction

Answer 26

consumes energy to synthesize complex molecules from simpler ones EX: condensation reactions

Question 27

catabolic reaction

Answer 27

releases energy by breaking down complex molecules into simpler ones EX: hydrolysis

Question 28

ways to regulate enzyme catalysis

Answer 28

by the amount of substrate, amount of enzyme available, inhibitors, enhancers, temp/pH if a protein

Question 29

understand feedback inhibition in terms of enzymes and products

Answer 29

use product to start a reaction from happening. Product becomes an allosteric regulator. will block different steps of a reaction

Question 30

explain the effect of pH/temperature on enzyme function

Answer 30

temperatrue: enzyme will unravel and denature due to the high kinetic energy of the molecules (too hot). the enzyme will denature due to the low kinetic energy of the molecules (too cold)-negative impact pH: protons=positively charged. mess with ionic bonds in the protein-negative impact

Question 31

competitive inhibitor

Answer 31

a molecule that competes for the active site, it will fit in the active site so the substrate cannot and inhibits the reaction

Question 32

noncompetitive inhibitor

Answer 32

a molecule that binds to the enzyme that causes the closing off or shape change of the active site causing the substrate to not be able to bond to the active site

Question 33

movement of H+ ions down the gradient is what type of transport

Answer 33

active transport to pump the ions, using energy, to pump from the mitochondria matrix to the inter membrane space. when the protons come through the ATP synthase by facilitated diffusion

Question 34

what has to be present in the membrane for NADH and FADH2 to drop off their energy and create ATP

Answer 34

proteins in the membrane | ATP synthase

Question 35

how is ATP produced in cell respiration-what process

Answer 35

cheimiosmosis process of oxidative phosphorylation

Question 36

what happens when signal molecules bind to tyrosine-kinase receptors

Answer 36

need two signal molecules to bind to the receptors that causes the tyrosine-kinase receptors to come together and form a dimer. The receptors have sites where phosphates and ATP can phosphorylate the dimer and changes the shape slightly. Then the relay proteins can attach to the activated tyrosine area to activate the relay protein and changes their shape. To inactivate take off signal molecule.

Question 37

how can the rate of reaction of an enzyme be measured

Answer 37

amount of product it is producing, measure of appearance of product, measure of disappearance of substrate

Question 38

effect of temp on cell respiration

Answer 38

plant: do better in warmer temperature animals: warm blooded have to regulate body temperature and burn more in colder temperatures to stay warm. cold blooded do not have to burn more in colder temperature