BIOL 1201 Chapter : Week 5

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azuremammoth471

15 Mar 2019

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Week 5: membrane permeability, size and shape of molecules, solubility in lipids, net electric charge, chemical properties, water moves freely across membrane, diffusion, physical property of matter, from high to low concentration (atoms, ions, molecules, ect) Side a: 1m sucrose, 2m glucose, 3m nacl. Side b: 2m sucrose, 3m glucose, 1m nacl. Side b, has higher concentration, needs more water to lessen: terminology of solutions (relative terms in relation to another solution, hypertonic, more concentrated, more solute outside of cell, water goes outside, shrivels up. Less concentrated: more solute inside the cell, takes in water, could blow up, 1m sugar in cell, 2m sugar outside of cell. Water leaves cell: single celled freshwater organism is placed in saltwater. The cell shrinks: passive transport, diffusion of substances across the membrane down their concentration gradient; does not require the cell to expend energy, diffusion (molecules that are permeable, small molecules.

Related Questions

Read the following scenarios and indicate which of the following processes they describe.

11. Sodium molecules move randomly around a solution of sodium chloride in water, frequently colliding with other sodium ions and chloride ions. secondary active transport diffusion osmosis facilitated diffusion primary active transport

12. Sodium ions (Na+) move through sodium channels in a synthetic membrane. primary active transport secondary active transport facilitated diffusion osmosis

13. Water molecules move into the cytosol of a cell placed in a hypotonic solution. primary active transport secondary active transport facilitated diffusion osmosis

14. Water molecules move into the cytosol of a cell placed in pure water. facilitated diffusion osmosis secondary active transport primary active transport

15. Water molecules move out of a cell placed in a hypertonic solution. facilitated diffusion primary active transport secondary active transport osmosis

16. The action of sodium-potassium pumps moves sodium ions (Na+) out of a cell and potassium ions (K+) into a cell. facilitated diffusion secondary active transport osmosis primary active transport

17. Glucose molecules move into cells lining the intestine against their concentration gradient driven by the movement of sodium ions (Na+) into the cells down their concentration gradient. osmosis secondary active transport primary active transport facilitated diffusion

18. A beaker of water is separated by a selectively permeable membrane that allows the passage of water but not ions. A solution of 4% sodium chloride (NaCl) is placed on one side of the membrane and pure water is placed on the other side of the membrane. The solutions are allowed to equilibrate. At this point, which process is going on? facilitated diffusion osmosis secondary active transport primary active transport

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Question 1

Plasma membranes are selectively permeable. This means that

	A.	glucose cannot enter the cell.
	B.	the plasma membrane allows some substances to enter or leave a cell more easily than others.
	C.	plasma membranes must be very thick.

Question 2

Oxygen molecules O₂ crosse a plasma membrane by

	A.	passive transport
	B.	osmosis
	C.	active transport

Question 3

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.

		A. energy and channel proteins; against (up)
		B. transport proteins that make channels ; down
		C. energy ; down

Question 4

When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will

		A. move to the side with lower water concentration
	B.	move to the side with higher water concentration
	C.	move to the side with lower solute concentration

Question 5

Kinetic energy differs from chemical energy in that

	A.	chemical energy is a particular form of kinetic energy.
	B.	kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.
	C.	kinetic energy is stored energy that has the potential to do work, and chemical energy is the energy of movement.

Question 6

When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction.

	A.	exergonic; endergonic
	B.	endergonic; exergonic
	C.	spontaneous; exergonic

Question 7

When an enzyme catalyzes a reaction

		A. it raises the activation energy of the reaction.
		B. it lowers the activation energy of the reaction.
		C. it is used once and discarded.

Question 8

Which of the following statements regarding enzyme function is false?

		A. An enzyme's function depends on its three-dimensional shape.
		B. Enzymes are very specific for their substrates.
		C. Enzymes are used up when they catalyze a chemical reaction so must be synthesized for each new chemical reaction

I have this questions for my homework i need help with them look please it is important i need help so please give me the correct answers for each question and also please be clear to understand and aslo be correct it is very important becuase i need them so i really need the right answers. please help me and on Questions 6 and 9 please help me with it hope you can help me with the correct answers please

Question 5

At a constant temperature, if you increase the number of unsaturated fatty acid chains in the phospholipid, the membrane will become......

less fluid

more fluid

fluidity will be unchanged

Question 6

Bacteria in a hot spring at 80 degrees celsius would be expected to have ______________ in their cell membrane

high proportions of saturated phospholipids

high proportions of unsaturated phospholipids

an equal ratio of saturated to unsaturated phospholipid

Question 7

Membrane proteins have an important role in membrane fluidity

True

False

Question 8

The HIV virus can't attach to cells that have a mutation in the CCR5 gene and so such individuals are resistant to HIV. What population of people have a higher incidence of the mutant CCR5 gene and why?

europeans because their ancestors survived the bubonic plague

North Americans because their ancestors survived small pox

europeans because they have a longer evolutionary past with HIV

Africans because they have a longer evolutionary past with HIV

Question 9

Nematode trapping fungi have ______________ molecules called ______________ that recognize specific carbohydrates on the surface of the nematode worms. This is how a fungus can recognize that its prey, the nematode worm, has wriggled into the loop. Write two words on lowercase separated by a space with no other syntax

Question 10

Diffusion requires energy

True

False

Question 11

The net direction of molecule movement when molecules diffuse is

down their concentration gradient

random directions

Question 12

In osmosis, water molecules from a solution of higher solute concentration cross a semi-permeable membrane into a solution of lower solute concentration?

True

False

Question 13

Which best defines osmosis?

In osmosis, water from a solution of lower solute concentration move across a semi-permeable membrane into a solution of higher solute concentration?

In osmosis, water from a solution of higher solute concentration move across a semi-permeable membrane into a solution of lower solute concentration?

Question 14

Animal cells placed into a hypotonic solution would most likely?

lyse (burst)

shrink

remain unchanged in size

Question 15